Hand - Extensor and Flexor Tendon Injury Flashcards
A 34-year-old woman who is a concert pianist is brought to the emergency department because of a laceration on the volar aspect of the right index finger at the mid-proximal phalanx caused by a broken vase. Operative exploration shows complete laceration of the radial digital nerve and the profundus and superficialis tendons in the flexor tendon sheath. Which of the following is the most effective management of the flexor tendon injury?
A ) Excision of the superficialis tendon; repair of the profundus tendon; early active-motion protocol
B ) Excision of the superficialis tendon; repair of the profundus tendon; immobilization for three weeks
C ) Repair of the profundus and superficialis tendons; early passive-motion protocol
D ) Repair of the profundus and superficialis tendons; immobilization for three weeks
The correct response is Option C.
The most effective management is profundus and superficialis tendon repair with early passive-motion protocol. Repairing the superficialis tendon not only improves strength and function but also has been shown to increase circulation to the tendon repairs.
Many studies have shown that a direct correlation exists between the strength of the tendon repair and the number of core sutures used across the repair (strength is proportional to the number of sutures).
Many studies have shown the strength and adhesion-prevention benefits of early passive-motion protocols. Some studies have advocated early flexion active-motion protocols, but none have found the results superior to the early passive-motion protocols. One study has also shown that early passive-motion protocols do not interfere with the outcomes of primary digital nerve repairs when Zone II flexor tendon and digital nerve injuries occur simultaneously.
Under normal conditions, the intrinsic muscles of the hand move the metacarpophalangeal, proximal interphalangeal, and distal interphalangeal joints in which of the following ways?
The correct response is Option D.
The intrinsic muscles are those with an origin and insertion within the hand and include the muscles of the thenar and hypothenar compartments, interossei, and lumbricals. They account for approximately 53% of grip strength and 85% of pinch strength. In general, the intrinsic muscles produce metacarpophalangeal joint flexion and interphalangeal joint extension, which occurs because the tendons of lumbrical and interosseous muscles are volar to the metacarpophalangeal axis of rotation but dorsal to the interphalangeal axis of rotation. The exception is when the metacarpophalangeal joint is hyperextended when the dorsal interosseous tendon is capable of producing extension. Tightness of these intrinsic muscles can be evaluated by the Bunnell-Littler test, whereby the force required to passively flex the proximal interphalangeal joint increases with extension of the metacarpophalangeal joint.
A 36 year-old-man comes to the office for follow-up examination four months after undergoing revision amputation at the distal interphalangeal joint of the left long finger to repair a partial traumatic amputation injury. Since undergoing the procedure, the patient has had difficulty making a fist. Physical examination shows extension of the proximal interphalangeal (PIP) joint when the metacarpophalangeal (MCP) joint is actively flexed. The patient has full active and passive range of motion of the PIP joint when the MCP joint is extended. Radiographs show no abnormalities. Which of the following is the most appropriate next step in management?
(A) Dynamic flexion splinting
(B) Fusion of the PIP joint
(C) Injection of a corticosteroid into the area of the A1 pulley
(D) Surgical release of the lumbrical
(E) Tenolysis
The correct response is Option D.
The patient described has a lumbrical plus deformity. This deformity occurs following amputation when proximal migration of the profundus tendon results in contracture of the lumbrical muscle. This contracture can result in tightness of the lumbricals, which produces paradoxical extension of the PIP joint during active flexion of the MCP joint. The lumbrical muscle is a component of the intrinsic extensor mechanism, which is responsible for MCP flexion and PIP extension. The lumbrical plus deformity is treated most appropriately by division of the lumbrical tendon.
Dynamic flexion splinting is occasionally used for extension contractures of the PIP joint caused by joint stiffness. Fusion of the PIP joint is indicated for cases of arthritis. Injection of a corticosteroid is appropriate if the patient has active triggering at the level of the A1 pulley. Tenolysis is used when flexor tendon adhesions are suspected (when passive joint motion is greater than active joint motion).
A 21-year-old man comes to the office after injuring the right long finger while playing football. On physical examination, the patient is unable to flex the distal phalanx. Hollowness is noted along the volar aspect of the finger, with pain in the palm upon palpation. X-ray studies show no abnormalities. Which of the following is the latest at which primary repair is expected?
A) 1 day
B) 1 week
C) 1 month
D) 2 months
E) 3 months
The correct response is Option B.
Rupture of the flexor digitorum profundus (FDP) tendon from its distal attachment is commonly known as jersey finger. The injury is often overlooked by players and trainers and misdiagnosed as a sprained finger, but it requires more urgent management than these minor injuries. Jersey finger occurs when a flexed distal interphalangeal (DIP) joint is suddenly and forcefully hyperextended, leading to rupture of the FDP tendon at its insertion on the distal phalanx.
FDP injuries can be classified based upon the degree of tendon retraction, as described in Leddy and Packer’s grading scheme:
Type I injuries involve retraction of the profundus tendon all the way to the palm, with associated injuries to the vincula longus and vinculum brevis. Injuries to the vincula disrupt the blood supply to the tendon, necessitating surgical repair within 7 days to avoid necrosis of the tendon and a permanent contracture deformity.
Type II injuries involve retraction of the tendon to the proximal interphalangeal (PIP) joint. The tendon stump is held in place by the vincula longus, which are often intact. An avulsion fracture sometimes occurs with type II injuries, and often becomes trapped in the A2 pulley. Without an observable bony fragment on x-ray study, it is impossible to determine the degree of retraction; thus, all type II injuries should be surgically repaired within 7 days.
Type III injuries involve a large avulsion fragment that is often intraarticular. The bony fragment prevents retraction past the A4 pulley and holds the tendon in near-anatomic position, obviating the need for urgent repair. Type III injuries are amenable to repair within 2 to 3 months.
Type IV injuries are type III lesions with the addition of an avulsion of the FDP tendon from the fracture fragment. Type IV injuries are rare but require urgent repair because of the disruption to the tendon’s blood supply.
A 30-year-old woman comes for follow-up 1 week after undergoing repair of the flexor digitorum superficialis (FDS) and flexor digitorum profundus (FDP) tendons in Zone II following a stab wound to her little finger. Physical examination shows that she is unable to flex her distal joint. MRI shows FDP tendon rupture. Which of the following is the most appropriate next step in management?
A ) FDS IV tendon transfer
B ) Free-tendon graft
C ) Fuse the distal interphalangeal (DIP) joint
D ) Repair FDP tendon
E ) No intervention at this time
The correct response is Option D.
Ruptures of repaired tendons usually occur postoperative days 7 through 10. The best way to diagnose the rupture is MRI when active flexion is relatively contraindicated. Early ruptures can be managed with urgent re-repair. Tendon transfers and grafting should be reserved as secondary reconstruction procedures and should not be needed when the native FDP is available and not shortened. Fusion should be reserved for salvage and in patients where shorter recovery times are beneficial, such as laborers. Doing nothing can lead to swan-neck deformities, adhesions, and stiffness.
A 46-year-old woman comes to the office because she cut her nondominant little finger while peeling an avocado 6 months ago. Since the time of the injury, the patient says that her grip has been weak. Physical examination shows a healed 1-cm scar over the volar aspect of the proximal phalanx. The patient is unable to actively flex the distal interphalangeal (DIP) or proximal interphalangeal (PIP) joint. Two-point discrimination shows no abnormalities on both the ulnar and radial sides of the injured finger. Tendon grafting will be performed to restore little finger flexion. Which of the following is the most important consideration to confirm before performing surgery?
A ) Function of the flexor digitorum superficialis tendon
B ) Location of the proximal flexor digitorum profundus (FDP) stump
C ) Normal passive range of motion
D ) Presence of a palmaris longus at either forearm
E ) Symmetry of grip strength
The correct response is Option C.
The most important preoperative achievement is the restoration of good passive flexion of the involved digit. This will allow active range of motion in the postoperative period.
Preoperative examination clearly shows no function of the flexor digitorum superficialis tendon. Therefore, in the setting of the sharp injury, it would not be expected to be improvable.
The location of the proximal FDP stump is not appropriate because it is not a significant factor in timing secondary tendon reconstruction; it would not be reasonable to consider planning a delayed primary repair 3 months out. And with a Zone 2 laceration and no FDP function, the FDP stump will be in the palm, due to tethering by the lumbrical muscle.
Confirmation of the presence of a palmaris longus at either forearm is not appropriate because the palmaris is not the only donor tendon for secondary finger flexor reconstruction. The plantaris is a viable option as well, as are the long toe extensors.
Preoperative strengthening of grip is not appropriate because it would do nothing to prepare the little finger for reconstruction.
An 18-year-old football player comes to the office because he has been unable to flex his ring finger since tackling an opponent during a game 3 hours ago. Physical examination shows the distal joint in the neutral position with an inability to actively flex. Which of the following is the most likely mechanism of injury?
A ) Forced axial load compression
B ) Forced distal interphalangeal (DIP) joint extension with simultaneous maximal flexion effort
C ) Forced metacarpophalangeal (MCP) joint extension with simultaneous maximal abduction effort
D ) Forced pilon style crush
E ) Forced proximal interphalangeal (PIP) joint extension with simultaneous maximal extension effort
The correct response is Option B.
Jersey injury occurs when a player grabs the opposing player’s jersey. The DIP joint is in a flexed position and when the tackle is broken, there is a forced extension. Flexor digitorum profundus (FDP) avulsion occurs 75% of the time in the ring finger. In Type I, the tendon only retracts into the palm and requires urgent repair and reinsertion within 7 to 10 days. In Type II, the tendon retracts to the PIP joint level being tethered by the long vinculum. Repair can be delayed 6 to 12 weeks. In Type III, a large bony fragment blocks the tendon from entering the A4 pulley and can be repaired at any time. The FDP insertion is avulsed from the distal phalanx with or without bone fragments. Force applied in any of the other vectors would not create FDP avulsion.
A 42-year-old man is brought to the emergency department after he sustained major injuries when he fell from a ladder. In addition to abdominal trauma, he sustained lacerations of the flexor carpi ulnaris tendons, ulnar artery, ulnar nerve, flexor digitorum profundus tendons, flexor digitorum superficialis tendons, flexor pollicis longus muscles, palmaris longus tendon, median nerve, radial artery, and flexor carpi radialis tendon of the right arm. During emergent exploratory laparotomy with general anesthesia, an upper arm tourniquet is inflated to 250 mmHg. Two hours later, when the laparotomy is completed, the tourniquet is still in place and the patient is asleep. Which of the following is the most appropriate management of the injuries to this patient=s hand?
(A) Release the tourniquet, close the skin, and repair the severed structures electively
(B) Release the tourniquet and repair the severed structures immediately
(C) Leave the tourniquet in place and repair the severed structures immediately
(D) Release the tourniquet for five minutes, reinflate the tourniquet, and repair the severed structures
(E) Release the tourniquet for 20 minutes, reinflate the tourniquet, and repair the severed structures
The correct response is Option E.
Difficult situations such as these often arise, especially in patients who have sustained multiple traumas. This patient has had a delay in the care of a cold hand because of a limb-threatening injury. Because of the threatened limb, closing the skin and performing the repairs on another day is not an option. Continuation of the tourniquet would be dangerous to this patient; the upper limit of time for tourniquet use in the upper extremity is most frequently defined as two hours, after which muscle and nerve damage begins. Performing the surgery without tourniquet control is an option but is not the best option in a true spaghetti-like wrist, for which a bloodless field is best for meticulous preparation and identification of structures. Of the options listed, the best choice is to release the tourniquet for 20 minutes (5 minutes for every 30 minutes the tourniquet was in use) and to finish the case immediately. Release of the tourniquet for only five minutes is not adequate after two hours of tourniquet use. Indeed, revascularization of the hand with closure of the wound, opting to finish the case on another day is an option, but was not offered as a choice for this item.
References
A 42-year-old right-hand–dominant construction worker is evaluated for an 8-week history of pain with wrist motion. Physical examination shows swelling 4 cm proximal to the Lister tubercle. There is tenderness to palpation and crepitation over the muscle bellies of the abductor pollicis longus and extensor pollicis brevis. The remainder of the examination shows no abnormalities. Which of the following is the most likely diagnosis?
A) Basal joint synovitis
B) de Quervain synovitis
C) Extensor pollicis longus tendinitis
D) Intersection syndrome
E) Wartenberg syndrome
The correct response is Option D.
Intersection syndrome is synovitis of the second dorsal compartment. It is located where the abductor pollicis longus and extensor pollicis brevis cross the extensor carpi radialis longus and extensor carpi radialis brevis. The syndrome often occurs in athletes with repetitive forceful extension. The swelling is located 4 to 6 cm proximal to Lister tubercle.
Basal joint arthritis and synovitis would have tenderness located at the wrist crease at the carpometacarpal joint and may have x-ray findings. de Quervain is synovitis of the first dorsal compartment, which would be located over the radial styloid and have a positive Finkelstein sign. Wartenberg syndrome is radial sensory nerve compression where the nerve exits the supinator muscle. Symptoms would be paresthesia over the radial nerve distribution and a Tinel sign. Extensor pollicis longus tendinitis is synovitis of the third dorsal compartment with vague dorsal wrist pain and tenderness, usually over the Lister tubercle with exacerbation with thumb extension.
A 36-year-old woman has a boutonniere deformity of the right middle finger after sustaining a closed central slip injury while playing volleyball two months ago. She is able to extend the proximal interphalangeal (PIP) joint passively to 0 degrees.
Which of the following is the most appropriate management?
(A) Buddy taping of the PIP joint
(B) Splinting the distal interphalangeal joint at 0 degrees
(C) Splinting the PIP joint at 0 degrees
(D) Primary repair of the PIP joint
(E) Open repair of the PIP joint
The correct response is Option C.
This patient has a boutonniere deformity, in which the extensor mechanism (comprised of the central slip, transverse and oblique retinacular ligaments, and lateral bands) becomes imbalanced. In patients with this deformity, the central slip is damaged and the transverse retinacular ligament is stretched. The lateral bands begin to drift volarly, eventually moving anterior to the center of rotation of the proximal interphalangeal (PIP) joint. As a result, the lateral bands flex the PIP joint, and passive extension of the PIP joint becomes impossible.
There are three stages of boutonniere deformity. Patients with stage 1 deformities can passively extend the PIP joint. With stage 2, the joint becomes contracted and cannot be extended fully, but the joint itself is not yet involved. Degeneration of the joint is seen in a patient with a stage 3 boutonniere deformity.
Because this patient has only a stage 1 boutonniere deformity, the most appropriate management is splinting the PIP joint in extension (ie, at 0 degrees) for a minimum of six to eight months. The distal interphalangeal (DIP) joint should be unencumbered and allowed to flex actively, and an exercise program should be initiated for joint rehabilitation.
Buddy taping is only useful for certain types of injuries involving the collateral ligament and volar plate. Splinting of the DIP joint in extension is appropriate for treatment of a mallet finger deformity. Primary repair and open repair are difficult procedures and are not advocated as management options for patients with stage 1 deformities.
A 22-year-old laborer underwent four-strand and epitendinous repair of a Zone II flexor digitorum profundus (FDP) and flexor digitorum superficialis (FDS) injury to the long finger of the dominant right hand 5 days ago. Early active motion therapy protocol is selected for rehabilitation, by which the injured finger is passively flexed and the wrist extended, with the patient then asked to actively maintain a flexed grasp. In contrast to the rubber band Kleinert technique, this protocol is most likely to have which of the following effects on the repaired finger?
A) Decreased risk of tendon rupture
B) Greater risk of finger flexion contracture
C) Increased FDP and FDS excursion
D) More tendon adhesions
E) Prolonged tendon repair softening
The correct response is Option C.
Low force and moderate excursion therapy protocols continue to be the most effective protocol following flexor tendon repairs. However, increasing the applied force to the repair site during postoperative rehabilitation beyond 5 N does not accelerate accrual of repair site strength after a multistranded repair. In vivo repair, results have shown that early active mobilization may limit tendon end softening and loss of repair strength that generally occurs after the first 7 days.
The mode of rehabilitation described was popularized by Strickland and has been shown to improve outcomes of Zone II repairs, probably due to both increased absolute as well as relative tendon excursions. However, in order to reduce the potential increased repair rupture rate, at least four-strand repair is required. This increased excursion leads to fewer tendon adhesions.
Because the fingers are flexed by rubber bands, the Kleinert technique predisposes the patient to flexion contractures. A combination of the Duran passive range of motion and the Kleinert technique improves the results.
A 62-year-old woman is evaluated for acute rupture of an extensor tendon after undergoing closed treatment of a nondisplaced distal radius fracture 6 months ago. The tendon most likely to be involved is located in which of the following extensor compartments?
A) First
B) Second
C) Third
D) Fourth
E) Fifth
The correct response is Option C.
Spontaneous rupture of the extensor pollicis longus (EPL) tendon is reported to occur in approximately 0.3 to 5% of nondisplaced or minimally displaced distal radius fractures, but it can also occur without trauma or in patients with inflammatory conditions such as rheumatoid arthritis. This is thought to arise from a loss of vascularity and atrophic changes in the compartment, and, because the tendon substance is usually degenerated, primary repair of the tendon is usually not possible. Tendon transfer using the extensor indicis proprius is the standard of care. Spontaneous rupture of other extensor tendons can occur in association with other conditions (e.g., rheumatoid arthritis), but would be exceedingly uncommon in the clinical scenario presented. The EPL passes through the third extensor compartment. Extensor tendon-compartment relationships include the following:
First - abductor pollicis longus, extensor pollicis brevis
Second - extensor carpi radialis longus, extensor carpi radialis brevis
Third - extensor pollicis longus
Fourth - extensor digitorum communis, extensor indicis proprius
Fifth - extensor digiti minimi
Sixth - extensor carpi ulnaris
A 24-year-old man comes to the office three months after sustaining a crush injury to the volar aspect of the right forearm during the rollover of a motor vehicle. Fasciotomies were performed when he awoke from a coma two days after the initial injury. Physical examination shows the digits flexed into the palm. Tenodesis effect without fixed contractures is present. A modified Henry fasciotomy scar is noted on the right forearm; skin coverage is otherwise excellent. No peripheral nerve injury is noted. Which of the following is the most appropriate surgical procedure to correct this deformity?
A ) Innervated free muscle transfer
B ) Muscle slide
C ) Resection of the intrinsic muscles
D ) Tendon lengthening
E ) Tendon transfers
The correct response is Option D.
The most appropriate surgical procedure for the correction of the deformity described is tendon lengthening. Patients with established ischemic forearm contractures are categorized by both the Holden and Tsuge classification systems. In Holden I injuries, the arterial ischemia and venous stasis begin proximal to the forearm fascial compartment. Holden II injuries are from direct trauma, and the ischemia begins at the site of the injury. The Tsuge classification defines the extent of muscle involvement as mild, moderate, or severe.
The patient described would be classified as a Holden II, mild type, because his ischemia was caused by direct trauma and his muscle involvement is limited to the deep flexors at the site of the injury. Z-plasty tendon lengthening and possible skin release and limited scarred muscle resection are sufficient.
Innervated free muscle transfers are reserved for Holden I or II, severe type, injuries. Often with nerve grafting in an attempt to establish protective distal sensation and other procedures, innervated free muscle transfers are utilized to provide both function and coverage in these patients with complete loss of muscle function after ischemic injury.
Muscle slide techniques are reserved for patients with Holden I, moderate injuries. These patients have ischemic changes affecting the entire muscle belly. Some of the muscles €™ contractile units should be intact. Combined with other procedures, the muscle slide permits a reduction of the distal contractures while preserving the muscle €™s residual contractile capabilities.
Resection of the dorsal intrinsic muscles and part of the adductor pollicis muscle is reserved for patients with ischemic contracture of the intrinsic muscles. Intrinsic ischemic contractures may accompany any ischemic Volkmann contracture, but this will often present as the hand assuming the intrinsic-plus position following reconstruction of the extrinsic musculature. The patient described is not presenting with an intrinsic-plus deformity.
Tendon transfers are used for patients with Holden II, moderate type, injuries. Proximal muscle slides are not usually performed because detachment of these healthy muscles will potentially diminish their functional capacity. Combined with other procedures, tendon transfers are used to augment any residual existing muscle function.
A 32-year-old woman comes to the emergency department after she sustained an isolated sharp transverse laceration of the flexor digitorum profundus tendon of the index finger of the left hand at the proximal interphalangeal joint flexion crease with a kitchen knife. A four-strand core suture is planned for repair. The ideal purchase length is which of the following distances from the cut tendon end?
A) 5 cm
B) 10 cm
C) 15 cm
D) 20 cm
The correct response is Option B.
For both two-strand and four-strand locking core repair methods, the length of core suture purchase significantly influences both resistance to gapping and also ultimate strength to breaking. The optimal length of purchase is between 0.7 and 1.0 cm. Increased length of purchase from 0.7 to 1.2 cm does not increase the repair strength. Purchase length of 0.4 or less greatly reduces repair strength.
A 19-year-old college baseball player comes for evaluation 4 weeks after he jammed and dislocated the long finger of his dominant right hand while sliding into home plate. His coach reduced the dislocation on the field. The patient says he has noticed increasing pain at the site of the injury in the past two days. Physical examination shows edema of the proximal interphalangeal (PIP) joint of the long finger. Lateral stress shows angulation of 30 degrees. X-ray study shows a congruous joint with radial side widening of 1 mm. Which of the following is the most appropriate management?
A) Buddy taping of the long finger to the index finger
B) Immobilization in a dorsal extension block splint at 30 degrees
C) Immobilization with a volar short arm splint
D) Kirschner wire fixation of the PIP joint for 3 weeks
E) Open repair of the radial collateral ligament
The correct response is Option E.
The goal of treatment is to restore normal finger function; prevent pain, stiffness, and traumatic arthritis; and to restore activities of daily living. This patient has a complete tear of the radial collateral ligament of the proximal interphalangeal (PIP) joint of the long finger. Widening of the joint space indicates probable interposition of ligament fibers. Angulation greater than 20 degrees is associated with poor prognosis. Complete tears with subluxation and interposition require surgical repair.Most collateral ligament ruptures occur at the proximal attachment to the middle phalanx.
Partial tears can be treated with nonsurgical and conservative methods. Splinting, buddy taping, extension block placement, and temporary fixation with a Kirschner wire would be incorrect.
A 35-year-old woman presents with a laceration of the left middle finger from a kitchen knife. Wound exploration in the emergency department prior to closure demonstrates partial flexor tendon laceration. Which of the following is an absolute indication for operative exploration?
A) Digital artery injury
B) Injury to the A4 pulley
C) 20% Laceration of the flexor digitorum profundus tendon
D) 40% Laceration of the flexor digitorum profundus tendon
E) Triggering
The correct response is Option E.
In one large meta-analysis, tendon lacerations up to 90% were managed with early protected range of motion. The only absolute indication for surgery from the list is triggering. There is no evidence that repairing the sheath or pulley without bowstringing is necessary. Isolated A4 laceration would not result in bowstringing. Single digital artery injury in the setting of a perfused digit does not necessitate repair.
A 60-year-old woman presents with weakness and inability to fully extend the right dominant thumb at the interphalangeal joint. History includes a Colles fracture of the right wrist 6 months ago. Management of the fracture included cast immobilization. On physical examination, the patient’s thumb is at 30 degrees of flexion. Finger metacarpophalangeal joint active extension is normal. The patient cannot extend or lift the thumb with her hand flattened on a table. With the thumb adducted, she can extend it to neutral. All thumb joints are supple and have full range of passive motion. Which of the following is the most likely cause of this patient’s inability to extend the thumb?
A) Intersection syndrome
B) Radial nerve palsy
C) Rupture of the extensor pollicis longus
D) Saddle deformity of the basal joint
E) Trigger thumb with locking
The correct response is Option C.
Extensor pollicis longus (EPL) rupture is most commonly caused by late effects of distal radius fractures. Devascularization is the most likely cause leading to attritional rupture. Rupture can present 2 weeks to 11 months after fracture; the average is 7 weeks. This patient can extend her thumb when it is adducted because of connections of the intrinsics with the dorsal apparatus. Tendon transfer of the extensor indicis proprius to distal EPL stump is the first-line treatment.
Other causes of EPL rupture include synovitis from rheumatoid arthritis and lupus causing friction at Lister’s tubercle, steroid injections, excessive abnormal wrist motion, bony spurs following distal radius and scaphoid fractures, scaphoid nonunion, misplaced external fixator pin, and subluxation of the distal ulna.
A trigger thumb would more likely have pain and tenderness on physical examination along the volar flexor sheath. A locked thumb would not have passive extensibility or active extension with adduction.
Saddle deformity is seen on physical examination in advanced osteoarthritis of the basal joint. Interphalangeal joint flexion of the thumb is caused by zigzag longitudinal collapse with hyperextension of the metacarpophalangeal joint.
Intersection syndrome is characterized by pain and tenderness along the radial side of the forearm where the abductor pollicis longus and extensor pollicis brevis muscles intersect.
Radial nerve palsy would not only affect the thumb interphalangeal joint.
A 25-year-old woman comes to the office with a 2-day history of difficulty moving the left thumb. Eight weeks ago, she sustained a nondisplaced distal radius fracture. She has been out of a cast for the past 2 weeks. On examination, thumb retropulsion is absent. Which of the following is the most appropriate definitive treatment?
A) Fusion of the carpometacarpal (CMC) joint of the thumb
B) Fusion of the interphalangeal (IP) joint of the thumb
C) Transfer of the anterior interosseous nerve to the recurrent branch of the median nerve
D) Transfer of the extensor indicis proprius (EIP) tendon to the abductor pollicis brevis tendon
E) Transfer of the EIP tendon to the extensor pollicis longus tendon
The correct response is Option E.
The scenario depicts a classic case of extensor pollicis longus (EPL) tendon rupture following distal radius fracture. The reported incidence of EPL tendon rupture ranges from 0.2 to 3%. Ruptures can occur after internal or external fixation due to impingement of hardware on the tendon or due to ischemic changes in the tendon due to swelling of the tendon and the third dorsal compartment.
Reconstruction of the EPL tendon can be accomplished either by tendon transplantation, typically the palmaris interposition between the proximal and distal healthy segments of the EPL tendon, or by transfer of the EIP to the distal segment of EPL tendon. When identified and treated before the EPL muscles retract and shorten, equivalent outcomes can be achieved. Later treatment necessitates tendon transfer.
Fusion of the thumb IP joint may be useful in flexor pollicis longus ruptures that cannot be repaired, but this would not restore thumb retropulsion.
Fusion of the CMC joint can alleviate pain from basal joint arthritis, but would result in further loss of motion of the thumb.
Transfer of the EIP to the abductor pollicis brevis and transfer of the anterior interosseous nerve to the recurrent branch of the median nerve are techniques for restoring thumb palmar abduction/opposition and would not restore retropulsion/extension.
An 18-year-old man is brought to the emergency department after sustaining a degloving injury to the dorsal aspect of the nondominant left hand in an all-terrain vehicle rollover. Physical examination shows loss of the soft tissues and the extensor tendons of the index, long, ring, and little fingers and an abnormal Allen test. Fractures of the second, third, and fourth metacarpal shafts are also present. Following serial debridements, the patient has a dorsal hand defect measuring 6 × 8 cm with obvious open fractures. Which of the following is the most appropriate management of the soft-tissue defect?
A) Anterolateral thigh free flap
B) Full-thickness skin grafting
C) Rectus abdominis muscle free flap
D) Reverse radial forearm flap
E) Split-thickness skin grafting
The correct response is Option A.
Degloving injuries of the dorsal hand are managed initially with serial debridements. Negative pressure dressings can also be used as a bridge to definitive soft-tissue reconstruction. Single-stage reconstruction involves bone fixation, tendon reconstruction, and soft-tissue coverage. Dorsal hand defects with exposed bone cannot be safely reconstructed with a split-thickness skin graft and require durable coverage. Although more durable than split-thickness skin grafts, full-thickness grafts cannot be expected to take over a large area such as this defect with exposed bone. Appropriate choices include the anterolateral thigh free flap or other perforator flaps (thoracodorsal artery perforator flap) or muscle flaps. A defect of the size described is best reconstructed with a perforator flap that minimizes donor site defects. Local flaps such as the reverse radial forearm flap can be used in the upper extremity, although advances in microsurgery have led to a decrease in use, so as to minimize the added morbidity of the already injured extremity.
A 30-year-old man comes to the emergency department after sustaining a laceration of the palm of the left hand from a knife. He reports difficulty flexing the ring finger of the left hand. A photograph is shown. Which of the following is the most appropriate method to clinically assess the integrity of the flexor digitorum superficialis tendon?
A) Hold the distal interphalangeal joint of the ring finger in extension and ask the patient to flex
B) Hold the index, long, and little fingers in extension and ask the patient to flex
C) Hold the long, ring, and little fingers flexed at the metacarpophalangeal (MCP) joint and ask the patient to flex
D) Hold the MCP joints of the index, long, and little fingers in flexion and ask the patient to extend
E) Hold the ring finger extended at the MCP joint and ask the patient to flex
Correct answer is option B.
The flexor digitorum superficialis (FDS) tendon flexes the proximal interphalangeal (PIP) joint. The flexor digitorum profundus (FDP) tendon can also flex the PIP joint, in addition to flexing the distal interphalangeal (DIP) joint. To confirm that the FDS tendon is flexing the PIP joint, FDP motion must be excluded. The FDP tendons to the long, ring, and little fingers share a common muscle belly. Thus, holding the long and little fingers in extension will prevent the FDP to the long, ring, and little fingers from firing. Any flexion of the PIP joint of the ring finger must then be caused by the FDS tendon. Holding the DIP joint of the ring finger in extension will prevent DIP flexion. It will not, however, prevent the pull of the FDP tendon from being transmitted to the PIP joint. Holding the long, ring, and little fingers flexed at the MCP joint will not exclude FDP motion. Holding the MCP joint of the ring finger extended will not exclude FDP motion. Asking the patient to extend will not assess the integrity of a flexor tendon such as the FDS.
A 57-year-old woman is seen in the emergency department after sustaining a closed crush injury to the dorsum of the right hand. X-ray studies are negative for fracture or dislocation. Examination shows swelling and an inability to actively extend the middle finger at the metacarpophalangeal joint from a flexed position. However, when the finger is placed in extension by the examiner, the patient is able to maintain the finger in extension and resist force. Injury to which of the following structures is the most likely explanation for these findings?
A) Central extensor tendon
B) Juncturae tendinum
C) Lumbrical muscle
D) Oblique retinacular ligament
E) Sagittal band
The correct response is Option E.
Injury to the sagittal band is most likely to account for these findings.
The patient has sustained a closed injury to the dorsum of the hand, resulting in a sagittal band rupture. The sagittal bands are responsible for maintaining the position of the extensor tendon dorsally over the metacarpophalangeal (MCP) joint. When this band is ruptured (commonly either via trauma or in rheumatoid arthritis), the extensor tendon can migrate laterally to the MCP joint and fall into the sulcus, causing difficulty in active initiation of extension. However, if the finger is placed in extension passively, the extensor tendon will resume its correct position and will then be able to hold the finger in extension and resist force.
Injury to the central extensor tendon will result in loss of active extension as well as an inability to maintain extension and resist force.
The juncturae tendinum connect the extensor tendons to each other at the dorsum of the hand. Pull via the juncturae may allow for some degree of extension function even in the presence of extensor tendon laceration, but injury to the juncturae should not create a deficit in extension if the tendon remains intact.
The lumbrical muscle is one of the intrinsic hand interosseous muscles. It functions to create flexion at the MCP joint and extension at the interphalangeal joints. Injury to the lumbrical muscle will not cause an extensor deficit at the MCP joint.
The oblique retinacular ligament is in the finger, originating at the base of the proximal phalanx and inserting into the distal phalanx. It is believed to coordinate proximal interphalangeal and distal interphalangeal motion but should have no bearing on motion at the MCP joint.
An 18-year-old football player comes to the office because he has been unable to flex his ring finger since tackling an opponent during a game 3 hours ago. Physical examination shows the distal joint in the neutral position with an inability to actively flex. Which of the following is the most likely mechanism of injury?
A) Forced axial load compression
B) Forced distal interphalangeal (DIP) joint extension with simultaneous maximal flexion effort
C) Forced metacarpophalangeal (MCP) joint extension with simultaneous maximal abduction effort
D) Forced pilon style crush
E) Forced proximal interphalangeal (PIP) joint extension with simultaneous maximal extension effort
Correct answer is option B.
Jersey injury occurs when a player grabs the opposing player’s jersey. The DIP joint is in a flexed position and when the tackle is broken, there is a forced extension. Flexor digitorum profundus (FDP) avulsion occurs 75% of the time in the ring finger. In Type I, the tendon only retracts into the palm and requires urgent repair and reinsertion within 7 to 10 days. In Type II, the tendon retracts to the PIP joint level being tethered by the long vinculum. Repair can be delayed 6 to 12 weeks. In Type III, a large bony fragment blocks the tendon from entering the A4 pulley and can be repaired at any time. The FDP insertion is avulsed from the distal phalanx with or without bone fragments. Force applied in any of the other vectors would not create FDP avulsion.
A 38-year-old woman comes for evaluation 7 weeks after undergoing a Zone II flexor tendon repair of the left long finger. She reports feeling a “pop” at home and is now unable to flex the finger at the proximal or distal interphalangeal joints. On examination today, the finger is swollen with moderate stiffness. Flexor tendon rupture is suspected. During operative exploration, ruptures of the flexor digitorum superficialis (FDS) and flexor digitorum profundus tendons are noted. There is a 1.5-cm gap of the profundus tendon and scarring at the A2 pulley. Which of the following is the most appropriate next step in management?
A) Excision of the flexor tendons with implantation of a passive silicone rod prosthesis
B) Fractional lengthening of the tendon in the forearm and revision of primary repair
C) Single-stage reconstruction with implantation of an active silicone rod prosthesis
D) Single-stage tendon reconstruction with palmaris graft
E) Tendon transfer from the ring finger FDS
The correct response is Option A.
Flexor tendon reconstruction in Zone II was originally described by Bassett and Carroll in 1963 and refined by Hunter in 1971. In the first stage, a Dacron-reinforced silicone rod is implanted after excision of the native tendons. It is secured distally to the flexor digitorum profundus stump or directly to the distal phalanx. Proximally, the rod is placed adjacent to the motor tendon but not secured. At this time, pulley reconstruction with tendon or retinacular grafts can be performed as indicated. This allows formation of a pseudosheath around the rod. Once the soft tissue has healed and the patient has regained maximum passive range of motion through therapy, the second-stage tendon grafting is performed. The most commonly reported time frame is 3 months but depends on soft-tissue stability.
The most important management decision is to determine if primary repair is possible. If not, one must then decide between single-stage and two-stage tendon reconstruction. The criteria for single-stage reconstruction include a finger with adequate passive motion of all joints, soft tissues with minimal scarring, functional tendon sheath and pulley system, a neurovascularly intact digit, and a compliant patient. If these criteria are not met, the patient should be treated with a staged reconstruction.
In this patient, primary repair is not likely with a gap >1 cm 7 weeks after the initial repair. Myostatic contraction of the proximal stump would be expected. In addition, this patient’s digit has significant internal scarring and poor passive motion— all factors that preclude a single-stage repair. Fractional lengthening might be considered to allow primary repair if the tendon sheath was better quality.
If a single-stage repair were indicated, one may consider a flexor digitorum superficialis transfer from an adjacent digit as a motor for the transfer. This requires only one tendon anastomosis, and studies have shown decreased adhesion formation with intrasynovial tendon grafts. However, tensioning of the transfer can be more difficult than traditional tendon grafting.
Patients who are unable to tolerate a second-stage procedure can be considered for the implantation of an active silicone rod prosthesis. This device is designed to have both a distal anastomosis to the bone and a proximal anastomosis to the motor muscle-tendon unit with integrated sutures or a loop. This would require meeting the criteria for single-stage reconstruction. Active implants were originally designed for use in two-stage reconstruction, but no studies exist that compare active with passive silicone rods or show any benefit versus a passive implant in a staged reconstruction.
Five weeks after undergoing primary repair of an injury to the flexor digitorum profundus tendon of the ring finger in zone II, a 33-year-old man suddenly loses the ability to flex the distal interphalangeal joint of the ring finger. A controlled trial of early motion was initiated following surgery.
Which of the following is the most appropriate next step in management?
(A) Continued occupational therapy
(B) Repeat operative exploration and repair
(C) Insertion of a silicone rod
(D) Tenolysis
(E) Arthrodesis
The correct response is Option B.
The most appropriate next step in management is repeat operative exploration and repair. This patient has most likely ruptured the flexor tendon. This typically occurs four to six weeks after initial repair and is most commonly caused by excessive grip force or significant devascularization of the tendon.
Further occupational therapy is not necessary in a patient who has good passive range of motion following rupture.
Staged reconstruction with insertion of a silicone rod and/or delayed tendon grafting is appropriate following tendon rupture if passive range of motion of the finger is significantly limited or there is an insufficient quantity of flexor tendon sheath.
Tenolysis is indicated in patients who have tendon adherence or scarring following tendon repair. This procedure is typically delayed for four to six months following the initial repair, and is most effect if the repair is intact and full passive range of motion is maintained.
Arthrodesis may be considered if the flexor tendons and flexor sheath cannot be repaired or reconstructed. This procedure provides stability but results in slightly flexed positioning of the finger.
A 53-year-old woman comes to the office after undergoing fixation of a humerus fracture 17 months ago. Physical examination shows inability to extend the wrist, fingers, and thumb. This has been present since the time of injury, without any recovery of function. Tendon transfers are planned. Transfer of which of the following muscles is most appropriate for restoration of wrist extension?
A) Brachioradialis
B) Flexor carpi ulnaris
C) Flexor digitorum profundus
D) Palmaris longus
E) Pronator teres
The correct response is Option E.
The most appropriate muscle to transfer for restoration of wrist extension is the pronator teres.
The radial nerve can be injured as a result of humerus fracture and/or surgery as it crosses the spiral groove of the humerus. The resultant radial nerve palsy will cause inability to extend the wrist, fingers, and thumb.
Reinnervation of the muscle ideally should be completed within 12 to 18 months after injury to allow for recovery. In this patient, who has high radial nerve palsy after humerus fracture, the time following injury has been too long, so nerve repairs or nerve transfers are not a viable option, and tendon transfer is the procedure of choice.
Tendon transfer involves the use of a noncritical or expendable donor tendon to provide a missing function. The tendon to be transferred should have adequate strength and range of motion to provide the desired function. Ideally the tendon used should have synergistic action and allow for tenodesis to facilitate reeducation.
The pronator teres is a median nerve–innervated muscle that has adequate power and excursion to provide wrist extension. It is typically transferred to the extensor carpi radialis brevis (as opposed to the extensor carpi radialis longus) in these cases to provide for more centrally oriented wrist extension.
The brachioradialis is a radial nerve–innervated muscle and will not be functioning in this patient who has a high radial nerve palsy. In low radial nerve palsies, it can be used to restore thumb extension. The brachioradialis can also be used to restore finger or wrist extension, as well as finger or thumb flexion in the appropriate patient.
The flexor carpi ulnaris would have adequate power and excursion, but it is not synergistic and it would be difficult to learn to use a wrist flexor to power wrist extension, as it provides an opposite function. This is typically used to restore finger extension, as it would take advantage of the tenodesis effect.
The flexor digitorum profundus would be synergistic with wrist extension, but it does not have independent muscle bellies and its use would require sacrifice of important finger flexor activity.
The palmaris longus does not have sufficient power to provide for wrist extension. It can be used as a transfer for thumb extension.
Which of the following best describes the origin and insertion of the lumbrical muscles?
The correct response is Option A.
The lumbrical muscles are intrinsic muscles of the hand. They arise from the flexor digitorum profundus tendon and insert into the radial lateral band of the extensor mechanism. Their origin and insertion both attach to muscle/tendon rather than bone, which makes them unique compared with other muscles, which typically originate from and insert into bone.
No muscles arise from the flexor digitorum superficialis tendon. The interosseous muscles originate from the metacarpal shafts and insert into the proximal phalanges.
A 25-year-old man who is a graduate student comes to the office for evaluation of the right ring finger 4 weeks after sustaining an axial impact. A diagnosis of soft-tissue mallet finger is noted. Which of the following is the most appropriate treatment in this patient?
A) Arthrodesis
B) Orthosis
C) Pinning in extension
D) Tendon grafting
E) Terminal tendon repair
The correct response is Option B.
Most of these injuries even after a month will respond to splinting of the DIP joint in extension for 6 weeks. Any residual extension lag is largely an aesthetic concern and rarely will require further treatment. The operative treatment of soft-tissue mallet injury may lead to unacceptable complications while splinting may lead to skin irritation but little else.
The preferred treatment at 4 weeks is closed reduction and splinting. Surgical treatment may be considered for more chronic injury greater than 3 months. Pinning in extension may be appropriate for a small subgroup of patients with work-related inability to wear an orthosis (such as surgeons).
A 47-year-old man comes to the office 6 months after undergoing tenodermodesis and application of a removable splint because of an open mallet finger injury with a knife to the dominant right hand. The patient was lost to follow-up despite being urged to return for routine follow-up visits, and says he removed his own sutures and discontinued the splint after 2 weeks. Physical examination shows a residual extensor lag of 25 degrees to the finger. A Fowler tenotomy is discussed regarding reconstructive options. Which of the following structures is most likely to be cut to restore extension of the distal phalanx in this patient?
A ) Central slip
B ) Lateral band
C ) Oblique retinacular ligament
D ) Terminal tendon
E ) Triangular ligament
The correct response is Option A.
The Fowler central slip tenotomy is well known, but seldom used. The central slip or tendon inserts on the base of the middle phalanx and acts on the proximal interphalangeal (PIP) joint. A central slip tenotomy will rebalance the extensor mechanism such that the terminal tendon will be able to extend the distal interphalangeal (DIP) joint in patients with a chronic mallet finger. However, many clinical and anatomical studies have shown that the central slip tenotomy may not restore full extension in patients with a preexisting lag of approximately 36 degrees.
Tension on the lateral bands also extends the DIP.
Release of the oblique retinacular ligament (ORL) or the lateral bands would, therefore, not assist in extension of the DIP joint.
Releasing the terminal tendon will only worsen the mallet finger because this is the structure that is disrupted in an open or closed mallet injury. Release of the triangular ligament would likely create a boutonnière deformity. PIP extension (produced by other tissues in the extensor mechanism) elongates the ORL, creating passive tension that extends the DIP.
A 24-year-old man with a 1-year history of poorly controlled diabetes mellitus comes to the office 3 months after sustaining a laceration of the left ring finger. Physical examination shows a thick but mobile cutaneous scar. Two-point discrimination in the fingertip is 7 mm, compared with 3 mm in other fingertips. There is no active or passive range of motion in the affected digit. Photographs are shown. Which of the following findings is most likely to preclude reconstruction in this patient?
A) Elevated hemoglobin A1c
B) Hypertrophy of the scar
C) Increased two-point discrimination
D) Length of time from the initial injury
E) Stiffness of the interphalangeal joints
The correct response is Option E.
Of the options listed, the most likely option to result in poor outcome in the setting of delayed tendon repair is stiffness of the interphalangeal joints. Hand therapy directed at achieving passive range of motion of the finger before reconstruction may make repair possible and should be attempted before proceeding with surgery.
Although poorly controlled diabetes increases the risk of perioperative infection, it would not impact the ability to perform a reconstruction. Likewise, the amount of time that has passed since the initial injury places the patient outside the range typically accepted for delayed primary repair, but would not directly affect a reconstruction.
Digital nerve injury requiring repair/reconstruction has been considered a relative contraindication to repair. The increased two-point discrimination in this patient suggests a prior injury with recovery similar to what might be expected with primary nerve repair. In this setting, the need for concomitant digital nerve repair is unlikely.
Although thick, the cutaneous scar is mobile, suggesting that it is not contributing to the lack of motion at the interphalangeal joints. Immature scars or wounds requiring further reconstruction would also be contraindications to reconstruction.
A 23-year-old man presents with a deep volar distal forearm laceration after striking a window. He is taken emergently to the operating room for repair of multiple flexor tendon, nerve, and arterial transections. Which of the following best describes the anatomical relationship of the flexor digitorum superficialis tendons so that the proximal and distal stumps can be correctly matched and repaired?
A) Index and middle superficialis tendons are volar to the ring and small superficialis tendons
B) Index and small superficialis tendons are volar to the middle and ring superficialis tendons
C) Index, middle, ring, and small superficialis tendons are arranged side-by-side
D) Middle and ring superficialis tendons are volar to the index and small superficialis tendons
E) Ring and small superficialis tendons are volar to the index and middle superficialis tendons
The correct response is Option D.
The superficial location of numerous, tightly packed vital structures at the volar aspect of the wrist/distal forearm makes them susceptible to injury with penetrating trauma. The patient presents with a “spaghetti wrist,” a term used to describe these devastating injuries that may result in transection of multiple flexor tendons and neurovascular structures.
A thorough knowledge of the anatomy in this region is required in order to appropriately align and repair all transected critical structures. In particular, the flexor digitorum superficialis tendons are arranged such that the middle and ring superficialis tendons are superficial to the index and small finger superficialis tendons. Of note, the flexor digitorum profundus tendons are arranged in a side-by-side fashion deep to the superficialis tendons. The median nerve is located between the superficialis and profundus musculotendinous units at this level.
The other options do not describe the correct arrangement of the superficialis tendons at the distal forearm/wrist level.
A 30-year-old man has a flexion deformity of the left long finger eight weeks after sustaining a router injury to the finger. The flexor digitorum profundus tendon was repaired at the time of injury. On current examination, the patient has weakness of all fingers of the left hand and limited flexion of the ring and small fingers. Which of the following is the most likely cause of the current findings?
A) Adhesions of the flexor digitorum profundus tendon
B) Lumbrical plus deformity
C) Quadriga effect
D) Rupture of the flexor digitorum profundus tendon
E) Triggering of the flexor digitorum profundus tendon
Correct answer is option C.
This patient’s deformity is most likely caused by the quadriga effect, which occurs as a result of excess distal pull on one profundus tendon. Because the flexor profundus tendons share a common muscle belly, any excess pull on one tendon will decrease the force and amplitude of all of the tendons. Quadriga can occur secondary to amputations in which the flexor digitorum profundus (FDP) tendon is attached to the extensor tendon or following grafting of excessively short tendons or advancement of the FDP tendon in patients with zone I injuries.
Flexor tendon adhesions can occur following injury or prolonged immobilization. Decreased flexion of the affected digit only is a characteristic finding.
Lumbrical plus deformity most frequently affects the index finger, which has an independent FDP tendon. Division of the distal tendon results in proximal migration of the tendon and lumbrical muscle, exacerbating tension on the lateral bands. This tension results in paradoxical extension of the proximal interphalangeal joint with attempted finger flexion.
A patient with a tendon rupture would be unable to flex the long finger; the other fingers would not be affected.
Triggering of the FDP tendon may be seen following tendon repair because of the excess bulk created as a result of the repair; this appears to interfere with the pulley system. Affected patients would have decreased motion of the long finger without any effect on the other fingers.
A 55-year-old right-hand-dominant man comes to the office because of a 1-month history of inability to extend the interphalangeal (IP) joint of the right thumb. The patient says he first injured his thumb after falling down a flight of stairs 15 months ago, and was treated with 6 weeks of cast immobilization. Physical examination shows flexion of the IP joint is to 45 degrees with no active extension present. No abnormalities were noted. X-ray study shows a united, nondisplaced distal radius fracture. Which of the following is the most appropriate management of this patient’s condition?
A ) Arthrodesis of the thumb IP joint
B ) Excision of bone spur and arthrodesis of the thumb IP joint
C ) Plate fixation of distal radius and tendon transfer of extensor indicis proprius (EIP) tendon
D ) Primary repair of extensor pollicis longus (EPL) tendon
E ) Tendon transfer of EIP to index EPL tendon
The correct response is Option E.
EPL tendon rupture occurs in 1% of fractures of the distal radius after closed reduction. The incidence of tendon rupture after closed treatment of distal radius fracture is actually greater than that of open treatment and plate fixation. Tendon ruptures may occur early, due to bone spurs, but they also may occur late, years after the fracture. This is believed to be due to an inflammatory synovitis in the area of the third dorsal compartment and a relative ischemia of the EPL tendon in this area. Ultrasound can help establish the diagnosis; the optimal treatment is tendon transfer from the EIP tendon. Arthrodesis of the thumb IP joint can prevent the flexion deformity of a tendon rupture, but it is not a preferred reconstruction method for a young, active person. Unless there is significant pathology at the distal radius, no specific treatment is required for the bone. Delayed primary repair of the EPL tendon is rarely possible.
One year after sustaining severe burns to the dorsal aspect of the left hand, a 48-year-old woman is unable to flex the proximal interphalangeal (PIP) joints of the left hand during maximal flexion of the metacarpophalangeal (MP) joints. She underwent operative release of contractures and full-thickness skin grafting over the MP joints nine months ago. Physical examination shows full extension and flexion of the MP joints. She is able to flex the PIP joints approximately 30 degrees with the MP joints fully extended. Radiographs of the hand show no arthritic or pathologic changes in the MP and PIP joints.
Which of the following is the most appropriate management?
(A) Intratendinous lengthening
(B) Release of the central slips
(C) Release of the check rein ligaments
(D) Release of the lateral bands
(E) Split-thickness skin grafting
The correct response is Option B.
The most appropriate management of the extensor tendon tightness seen in this patient is release of the central slips. Central slip releases can be performed under local anesthesia to immediately improve flexion of the proximal interphalangeal (PIP) joint. This simple maneuver may eliminate the need for extensive soft-tissue reconstruction as long as the scar and tendon contractures are located on the dorsal aspect of the hand and the lateral bands, which supply extensor power to the PIP and distal interphalangeal (DIP) joints, are intact. The risk for subluxation of the intact lateral bands and subsequent development of a boutonierre deformity is minimal.
Intratendinous lengthening is performed in patients who have contractures of the extrinsic flexor tendons resulting from cerebral palsy or stroke. Because the metacarpophalangeal (MP), PIP, and DIP joints can all be affected, this technique is primarily recommended to improve the appearance of the hand.
Patients who have intrinsic tendon tightness that does not improve with therapy may be considered for release of the lateral bands. In this condition, which is often a sequela of compartment syndrome, the intrinsic tendons of the hand are foreshortened, and flexion of the PIP joint is inhibited when the MP joints are fully extended.
Although the scar contractures can be released to relieve some of the stiffness in the PIP joints, the affected area should be covered with full-thickness skin grafts (instead of split-thickness grafts) because they provide superior skin quality and decrease the risk for secondary contractures.
A 32-year-old man who works as a carpenter comes to the office for follow-up examination seven days after sustaining a 2-cm laceration to the dorsum of the left thumb proximal to the interphalangeal joint while using a knife. In the emergency department, the laceration was sutured, and the thumb was immobilized with a splint. On physical examination, the wound is clean. No infection is noted. Weak extension of the interphalangeal joint is noted. The patient cannot extend the thumb off the tabletop. Laceration of which of the following tendons is most likely?
A) Abductor pollicis longus
B) Extensor carpi radialis brevis
C) Extensor carpi radialis longus
D) Extensor pollicis brevis
E) Extensor pollicis longus
Correct answer is option E.
The patient described has an injury to the extensor pollicis longus (EPL) tendon, which can be difficult to diagnose in the emergency department. Often, a patient will have weak active extension at the interphalangeal joint. The thumb extensor mechanism receives fibers from the abductor pollicis brevis, adductor pollicis, the ulnar head of the flexor pollicis brevis, and the EPL. If the EPL is lacerated, there may be weak extension at the interphalangeal joint; however, the thumb cannot be actively lifted off a tabletop. The extensor pollicis brevis, abductor pollicis longus, extensor carpi radialis longus, and extensor carpi radialis brevis do not contribute to the extension of the thumb off a tabletop.
A 32-year-old man comes to the office because of a “mallet” deformity of the distal joint of the long finger of the dominant hand sustained 12 years ago while he was playing baseball. He has not sought medical treatment until now. On examination, which of the following deformities is most likely?
A) Boutonnière
B) Camptodactyly
C) Clinodactyly
D) Hook-nail
E) Swan-neck
Correct answer is option E.
Flexion deformity of the distal joint seen in mallet finger will lead to secondary hyperextension of the proximal joint. This occurs in a zigzag fashion because of the imbalance of forces. If the terminal tendon is displaced proximally, the conjoined tendons will slide proximally and become extensors to the proximal joint. A boutonnière deformity is a flexion deformity of the proximal joint from disruption of the central slip. The lateral slips migrate volarly becoming an extensor to the distal joint which then hyperextends. Clinodactyly is a genetic condition in which there is a curvature of the fifth finger toward the fourth finger. A hook nail usually results from loss of nail bed support, usually after amputation. Camptodactyly is also a genetic condition in which there is a fixed flexion deformity of the proximal joint of the little finger.
Which of the following tendons comprise the compartment that forms the volar border of the anatomic snuff box?
A) Abductor pollicis brevis and extensor pollicis longus
B) Abductor pollicis longus and extensor pollicis brevis
C) Extensor digitorum communis and extensor indicis proprius
D) Extensor pollicis longus and abductor pollicis longus
E) Flexor carpi radialis and flexor pollicis longus
Correct answer is option B.
The volar border of the anatomic snuff box is comprised of the abductor pollicis longus (APL) and extensor pollicis brevis (EPB) tendons (first dorsal compartment). The dorsal border is comprised of the extensor pollicis longus (EPL) tendon (third dorsal compartment).
The above diagram shows the dorsal compartments of the forearm. The abductor pollicis brevis tendon is the most radial component of the thenar musculature; the extensor digitorum communis (EDC) and extensor indicis proprius (EIP) tendons are found in the fourth dorsal compartment. The flexor carpi radialis (FCR) tendon can be found radial to the other tendons within the superficial compartment of the volar forearm at the level of the wrist. The flexor pollicis longus (FPL) tendon lies within the deepest compartment of the volar forearm.
A 15-year-old boy is brought to the emergency department because he felt a “pop” followed by acute pain in his left ring finger while grabbing an opposing player’s jersey during a rugby match. Physical examination shows pain, tenderness, and swelling over the volar aspect of the finger, from the area of the distal interphalangeal joint flexor crease to the proximal interphalangeal (PIP) joint crease. The distal phalanx rests at neutral and no active flexion is possible. The patient can flex at the PIP with minimal discomfort. Which of the following is the most appropriate management?
A) End-to-end flexor tendon repair
B) Flexor tendon reinsertion
C) Open reduction and pin fixation of the middle phalanx
D) Splinting, followed in 2 weeks by range-of-motion exercises
E) Tendon transfer
Correct answer is option B.
The scenario described provides a classic example of a distal flexor tendon avulsion. Because of several potential factors, the ring finger is the most common finger to present with this type of injury. The flexor digitorum profundus of the ring finger has a less robust insertion at the distal phalanx than the long finger, which is a tip-off in the vignette for this classic injury. Yet the ring finger is similarly involved in the type of hyperextension force, or resisted flexion force, which generates this injury. The little finger does not present as much with this injury either. Flexor tendon reinsertion is correct, because the indicated management is early operation and reinsertion, if possible, of the avulsed tendon. This can be accomplished in a variety of ways, but that discussion is not central to the question. Splinting, followed in 2 weeks by range-of-motion exercises is wrong, because that answer describes how one might treat a sprain, which this is not. If one treated the tendon avulsion conservatively, and incorrectly, by splinting, the surgeon would lose the window for early repair, and the outcome for the patient would be poor. Secondary or delayed reconstruction in these cases is often not possible, and when possible, they often have results inferior to immediate repair. Tendon transfer is wrong because tendon transfers are not used for immediate repair of flexor avulsions. Tendon transfers are useful for secondary reconstruction in nerve palsies, for example. But they are not relevant to this distal and acute injury, confined to a single digit. Open reduction and pin fixation of the middle phalanx is wrong because the injury is not a fracture of the middle phalanx. It is true that one form of the flexor avulsion can involve an avulsion fracture off of the volar aspect of the distal phalanx, and that reinsertion of the fragment is part of the repair. But flexor tendon avulsion does not involve fracture of the middle phalanx. Furthermore, this is not an avulsion of the flexor digitorum sublimis because the patient flexes at the PIP with minimal discomfort, as per the vignette. End-to-end flexor tendon repair is wrong because this injury is a tendon avulsion from a distal bony insertion. There is no distal tendon to which to perform an end-to-end repair. Successful repair of a flexor digitorum profundus (FDP) avulsion really requires some form of anchoring of the distal FDP to distal phalanx bone.
A 23-year-old man sustains a stab injury to the volar wrist in the region of the carpal tunnel. Examination shows absence of flexion function at the proximal interphalangeal joint of the index finger when the remaining fingers are held in extension. He retains flexor function of the distal interphalangeal joint of the index finger. A diagram of the carpal tunnel contents is shown. Which of the following is the most likely location of the injured tendon?
The correct response is Option C.
Finger flexion results from the actions of the flexor digitorum superficialis (FDS) and flexor digitorum profundus (FDP) tendons. The FDS tendon inserts into the middle phalanx and provides for flexion at the proximal interphalangeal (PIP) joint. The FDP tendon inserts into the distal phalanx and is the only tendon that provides flexion at the DIP joints. Because it also crosses the PIP joint, the pull of the FDP tendon can result in flexion at the PIP joint as well. To independently examine the flexor tendons, the FDP tendon can be neutralized by holding the remaining fingers in extension. Due to a common muscle belly, the FDP will not act upon the finger, allowing inspection of the FDS tendon function by evaluating PIP joint flexion in this situation.
The patient has sustained a flexor tendon laceration in the region of the carpal tunnel. On physical examination, there is absence of flexion function at the index finger of the PIP joint when the remaining fingers are held in extension, indicating laceration to the flexor digitorum superficialis of the index finger.
At the level of the carpal tunnel, the flexor tendons travel through a fibro-osseous canal, which contains nine flexor tendons along with the median nerve. The FDS tendons of the middle and ring fingers are most superficial, with the FDS tendons of the index and small fingers deep to them. The FDP tendons lie parallel to each other at the deepest aspects of the carpal tunnel along the bone. The flexor pollicis longus is the most radial structure within the carpal tunnel. The cross-sectional anatomy of the wrist at the level of the carpal tunnel is diagrammed, along with the corresponding tendon locations in the two images shown:
A – FDS middle
B – FDS ring
C – FDS index
D – FDS small
E – FDP index
F – FDP middle
A 27-year-old man comes to the office because of an inability to extend the distal phalanx of the long finger after slamming it in a door 3 hours ago. Physical examination shows that the distal phalanx of the long finger is held in 75 degrees of flexion. The patient has no active extension of the joint. Ecchymosis and swelling over the distal interphalangeal (DIP) joint is noted. No skin laceration or abrasions exist. X-ray study shows no fracture. A congruent joint is noted. Which of the following is the most appropriate management?
A ) Arthrodesis of the DIP joint in 15 degrees of flexion
B ) Exploration and repair of the extensor tendon
C ) Percutaneous pin fixation of the DIP and proximal interphalangeal (PIP) joints
D ) Splinting of the DIP joint at 0 degrees
E ) Observation only
The correct response is Option D.
Avulsions of the terminal extensor tendon, as well as mallet fingers, are some of the most common hand injuries. Tendon avulsion from the distal phalanx may involve the tendon itself or a portion of its bony attachment. In the absence of large joint subluxation or fractures involving large fracture fragments, conservative nonoperative management with splinting is the recommended treatment.
Conservative treatment involves splinting in extension or slight hyperextension. This can involve prefabricated stack splints, malleable aluminum splints, or casting. Outcomes of each of these treatments are similar, but the type of splinting is generally more limited by skin irritation. Pin fixation for the DIP joint is recommended for patients who cannot tolerate splinting or those with special circumstances, such as a surgeon who requires unencumbered use of the hand. Pin fixation should cross the DIP joint only.
A 24-year-old, right-hand-dominant man comes to the office because of a 2-year history of a deformity of the ring finger of the left hand that has worsened progressively. History includes rheumatoid arthritis that is managed with multiple disease-modifying medications. A photograph and an x-ray study are shown. Which of the following anatomical abnormalities is the most likely cause of this patient’s ring finger deformity?
A) Contraction of the oblique retinacular ligament
B) Flexor digitorum profundus avulsion at the distal interphalangeal (DIP) joint
C) Palmar subluxation of the metacarpophalangeal (MCP) joint
D) Rupture of the central slip of the extensor mechanism
E) Volar plate laxity of the proximal interphalangeal (PIP) joint
The correct response is Option E.
Swan-neck deformity can occur in the post-traumatic setting as well as in the rheumatoid arthritis population. The PIP joint hyperextends, and the DIP joint flexes. Unlike boutonnière deformity, which is always initiated by a rupture of the central slip of the extensor mechanism, the origin of a swan-neck deformity can be at the DIP, PIP, or MCP joint. Regardless of the initiating problem, a swan-neck deformity can only occur if there is laxity of the volar plate of the PIP joint to allow hyperextension.
Flexor digitorum profundus avulsion would lead to inability to flex the DIP joint and would not cause hyperextension of the PIP joint. The oblique retinacular ligament can be used to repair a swan-neck deformity but is not causative of the pathology. Palmar subluxation of the MCP joint can lead to a swan-neck deformity in rheumatoid arthritis patients, but the photograph and x-ray study show this is not present in this patient. Rupture of the central slip of the extensor mechanism would lead to a boutonnière deformity.
References
A 16-year-old girl is brought for evaluation because she has been unable to extend her left ring finger since the tip of her finger was struck by a basketball during a game 3 hours ago. On physical examination, she is unable to straighten the distal interphalangeal (DIP) joint. An extensor lag of 35 degrees is noted. X-ray study shows no fracture or dislocation. Which of the following is the most appropriate management?
A) Arthrodesis of the DIP joint
B) Continuous extension splinting of the distal phalanx
C) Exploration and suture of the torn tendon
D) Open repair with reinsertion of the tendon into bone
E) Splinting of the proximal interphalangeal (PIP) joint in extension with the DIP free
The correct response is Option B.
The most appropriate management is continuous extension splinting of the distal phalanx.
The patient has sustained a mallet injury to the left ring finger. There is tearing of the terminal extensor tendon from its insertion at the base of the distal phalanx, resulting in inability to extend the finger at the DIP joint. On occasion, these injuries may be associated with an avulsion fracture from the dorsal aspect of the distal phalanx.
The majority of closed mallet injuries (Type I) in Zone I of the extensor tendon can be treated by continuous extension splinting for 6 to 8 weeks. It is important that the finger not be allowed to flex at the DIP joint during this time period to avoid disruption of healing.
Arthrodesis of the DIP joint is reserved for cases of DIP joint arthritis and would not be necessary in this patient.
Exploration and suture of the tendon can be performed, but results are no better than closed treatment due to the difficulty of obtaining adequate repair of the thin tendinous substance at this level. Additionally, the patient will still require prolonged immobilization of the DIP joint after open repair. Exploration and suture of the tendon is used to treat Type II (open) mallet injuries.
Open repair with reinsertion of tendon into bone is performed in flexor digitorum profundus avulsion injuries.
Splinting of the PIP joint in extension with the DIP joint free is used to treat Zone III extensor tendon injuries (central slip avulsion injuries).
A 53-year-old woman is evaluated for stiffness of the right index finger. On physical examination, the range of motion of the proximal interphalangeal (PIP) joint is 0 to 45 degrees when the metacarpophalangeal (MCP) joint is in extension (at 0 degrees). With the MCP joint in flexion (at 90 degrees), the PIP joint range of motion is 0 to 80 degrees. Which of the following conditions is most likely to account for these findings?
A) Contracture of the PIP joint capsule
B) Extensor tendon shortening
C) Flexor tendon adhesions
D) Intrinsic tightness
E) Palmar fascia hypertrophy
The correct response is Option D.
The condition most likely to account for these examination findings is intrinsic tightness.
This patient exhibits exam signs consistent with stiffness as a result of intrinsic tightness. The Bunnell test for intrinsic tightness involves comparing flexion at the proximal interphalangeal (PIP) joint with the metacarpophalangeal (MCP) joint extended, to flexion at the PIP joint with the MCP joint flexed. In cases of intrinsic tightness, PIP joint flexion will decrease when the MCP joint is extended, and there is increased flexion of the PIP joint when the MCP joint is flexed.
The intrinsic muscles are responsible for flexion at the MCP joints and extension at the PIP joints. When these are tight, PIP joint motion is decreased when the MCP joint is held in extension. There is increased PIP joint flexion possible when the MCP joint is placed in a flexed position because of the decreased tension on the intrinsic muscles that results with MCP flexion, allowing for improved PIP range of motion.
In cases of extensor tendon shortening or tightness (extrinsic extensor tendon contracture), the opposite effect is seen. MCP joint flexion will place additional tension on the extensor mechanism, tightening it and resulting in decreased flexor function at the PIP joint, when compared with an extended MCP joint.
Flexor tendon adhesions and contractures of the PIP joint capsule can result in stiffness but would give equal limitations to PIP flexion regardless of MCP joint position. Palmar fascia hypertrophy is seen in Dupuytren contracture. This contracture could potentially limit PIP extension, which might vary with MCP position, but would not limit flexion of the PIP joint as described in this item.
An 18-year-old college student sustains an injury to the nondominant small finger when he falls while playing flag football. On physical examination, the finger is swollen slightly and held in a flexed position. Active flexion and extension of the finger are limited by pain. A radiograph is shown above. Closed reduction of the finger in the emergency department is unsuccessful.
The most likely cause is interposition of which of the following structures within the joint?
(A) Extensor tendon
(B) Flexor tendon
(C) Joint capsule
(D) Neurovascular bundle
(E) Volar plate
The correct response is Option A.
This 18-year-old college student has sustained a volar dislocation of the proximal interphalangeal (PIP) joint, an injury so named because the middle phalanx is dislocated volar to the proximal phalanx. In volar dislocations, which are far less common than dorsal dislocations, the extensor tendon is torn by the distal condyle of the proximal phalanx, as shown in the intraoperative photograph above. If the condyle has pushed through the extensor tendon, the tendon may tighten and act as a sling to prevent reduction of the dislocation.
Although some physicians may be able to perform closed reduction, operative exploration and repair are recommended because of the possible injury to the extensor tendon. Unsuccessful closed reduction is an absolute indication for operative exploration, as repeat attempts at manipulation will only worsen edema and may contribute to injury. In addition, volar dislocations can be associated with complete avulsion of the central slip, requiring repair.
Although the flexor tendons and volar plate can become interposed within the joint and interfere with closed reduction, this is a rare finding in patients with volar dislocations and is more likely to be associated with irreducible dorsal dislocations. The joint capsule and neurovascular bundle are not involved in volar dislocations of the PIP joint.
A 24-year-old male figure skater comes to the emergency department because of dorsal metacarpophalangeal dislocation of the right thumb. The emergency department staff is unable to reduce the dislocation. Which of the following structures is most likely preventing reduction in this patient’s injury?
A) Extensor pollicis longus tendon
B) Flexor pollicis brevis tendon
C) Opponens pollicis
D) Sesamoid bone
E) Ulnar neurovascular bundle
The correct response is Option D.
The thumb metacarpophalangeal (MCP) sesamoid bone(s) may be associated with an irreducible dorsal dislocation.
Dorsal dislocation of the thumb at the MCP joint typically occurs with forced hyperextension with resultant volar plate and collateral ligament rupture. Irreducibility usually occurs through interposition of the volar plate in the joint. Extensor expansion interposition, collateral ligaments, bony fragments, sesamoids, and flexor pollicis longus entrapment have also been associated with irreducibility. In these circumstances, open reduction is often necessary.
The ulnar neurovascular bundle, extensor pollicis longus, opponens pollicis, and flexor pollicis brevis are not typically associated with an irreducible dislocation.
A 16-year-old boy is brought to the office after “jamming” the right long finger of the dominant hand while playing football. Upon active extension, the patient exhibits an extension lag of 40 degrees at the proximal interphalangeal (PIP) joint, and hyperextension at the distal interphalangeal (DIP) joint. Which of the following is the most likely diagnosis?
A) Central slip disruption
B) Flexor digitorum profundus avulsion
C) PIP volar plate tear
D) Sagittal band rupture
E) Swan neck deformity
Correct answer is option A.
This is the basis of the Elson test for central slip disruption of the extensor mechanism of the finger. When the proximal interphalangeal (PIP) joint is maximally passively flexed, the central slip is normally pulled distally, resulting in slack in the terminal tendon. Injury to the central slip eliminates this slack through the lateral band and allows extensor tension to be generated at the distal interphalangeal (DIP) joint. Thus, with central slip injury, the DIP joint can be actively extended with maximal PIP flexion. Swan neck deformity results from terminal extensor tendon disruption and total inability to extend the DIP joint independent of PIP position. Flexor digitorum profundus (FDP) avulsion results in inability to flex the DIP joint. In the Elson test, DIP flexion is always possible. PIP volar plate injury may result in jamming of the volar plate within the PIP joint and paradoxical inability to flex (extension contracture) at the PIP joint. There will also be hyperextension PIP joint pain and laxity. Sagittal band disruption results in inability to actively extend at the metacarpophalangeal joint, but the finger can often maintain extension if passively placed in this position.
A 35-year-old man presents with a laceration to the dorsum of his nondominant hand sustained with a kitchen knife. Examination shows a laceration to the metacarpophalangeal (MCP) joint of the long finger. There is no obvious joint involvement, but the patient has an extensor lag of 30 degrees at the MCP joint. Surgical repair of the Zone 5 extensor digitorum communis tendon is performed. Postoperatively, which of the following treatment plans is most likely to provide this patient with the most motion and best outcome?
A) 1 week of immobilization followed by relative motion splint and short arc motion
B) 2 weeks of immobilization followed by dynamic extension splint
C) 3 weeks of immobilization followed by full motion
D) 4 weeks of immobilization followed by protected motion
E) No postoperative orthosis and released to full motion immediately
The correct response is Option A.
Traditionally, extensor tendon injuries were treated with 4 to 6 weeks of immobilization that would subsequently lead to decreased flexion and stiffness. More recently, short arc motion protocols with relative motion splints have been utilized and demonstrate improved outcomes. To do this, a thermoplastic yoke splint is constructed by placing the digits of the repaired extensor tendon in approximately 15 to 20 degrees more metacarpophalangeal extension than the adjacent digits for 6 weeks while allowing full interphalangeal joint motion. The wrist is typically placed into an extension splint for 3 weeks at approximately 20 degrees extension to decrease tension on the repair site. Dynamic splinting following extensor tendon repair still limits gliding of the tendon by keeping the digit in a relative static position.
A 50-year-old man who is a biathlete comes to the office because of weakness and pain when gripping or pinching with the left hand. Medical history includes a sprain to the left thumb with forced radial abduction 1 year ago. Physical examination shows a difference in stability of the right thumb and the left thumb during stress testing. Photographs are shown. Which of the following is the most appropriate treatment for this patient’s metacarpophalangeal (MCP) joint injury?
A) Direct repair of the collateral ligament
B) Graft reconstruction of the collateral ligament
C) Occupational therapy for strengthening of the adductor muscle
D) Placement of a short opponens splint for 6 weeks
E) Transfer of the extensor indicis proprius tendon to the adductor insertion
The correct response is Option B.
Injuries to the ulnar collateral ligament (UCL) of the thumb metacarpophalangeal joint (skier’s thumb Injury) can be successfully treated with 4 weeks of immobilization provided that the injury results in either no instability, or limited (<30 to 35-degree laxity under load, or <10 to 15-degree difference from the contralateral UCL under load) instability. The photographs provided show 40 to 45 degrees of laxity, which differs substantially from the contralateral (<10 degrees) thumb. Treatment of this injury requires operative intervention. Incomplete injuries, or injuries with only mild symptomatic laxity, may benefit from occupational therapy. The adductor muscle provides a stabilizing force across the metacarpophalangeal joint and has been a target for treating mild injuries that result in some degree of instability. This would be insufficient for treating this complete rupture. In a similar fashion to strengthening the adductor muscle, addition of another force directed at providing ulnar adduction at the metacarpophalangeal joint has been proposed. As in the case of adductor strengthening, however, this would be inadequate to treat the complete rupture apparent in the clinical photos. When encountered acutely, unstable, complete ruptures of the ulnar collateral ligament of the thumb metacarpophalangeal joint are optimally treated with operative repair. Four to six weeks following the injury, direct repair may be difficult if not impossible. In this patient, the presentation for treatment occurs one year after the initial injury, making repair of the UCL extremely unlikely. On operative exploration in this patient, only a shortened stump of UCL remained attached to the metacarpal head. Chronic unstable injuries of the thumb metacarpophalangeal (MCP) joint ulnar collateral ligament (UCL) may be symptomatic via weakened grip and pinch as well as pain. Treatment in this setting will be dictated by patient needs and by the status of the joint. Patients requiring mobility and lacking arthritic degeneration at the MCP joint are candidates for UCL reconstruction. Reconstruction will typically be accomplished by use of a tendon graft, either palmaris or plantaris, placed through bone tunnels and secured through one of multiple methods (interference screws, periosteal sutures, bone anchors). Given this patient’s presentation one year out from the initial injury, reconstruction is the best option.
A 49-year-old man comes to the office because he has been unable to extend the wrist, fingers, and thumb of his right hand since fracturing his humerus 16 months ago. He underwent open reduction and internal fixation at that time. The fracture healed well. There has been no change in function since the procedure. Physical examination shows the patient is unable to actively extend the wrist, fingers, and thumb. Tendon transfers are planned. Which of the following is the most appropriate muscle to transfer for restoration of finger extension?
A) Brachioradialis
B) Extensor carpi radialis longus
C) Flexor carpi ulnaris
D) Palmaris longus
E) Pronator teres
The correct response is Option C.
The most appropriate muscle to transfer for restoration of finger extension is the flexor carpi ulnaris.
The radial nerve can be injured as a result of humerus fracture and/or surgery as it crosses the spiral groove of the humerus. The resultant radial nerve palsy will cause inability to extend the wrist, fingers, and thumb.
Reinnervation of the muscle ideally should be completed within 12 to 18 months following injury to allow for recovery. In this patient who has radial nerve palsy after humerus fracture, the time following injury has been too long, so nerve repairs or nerve transfers are not a viable option, and tendon transfer is the procedure of choice.
Tendon transfer involves the use of a noncritical or expendable donor tendon to provide a missing function. The tendon to be transferred should have adequate strength and range of motion to provide the desired function. Ideally, the tendon used should have synergistic action and allow for tenodesis to facilitate reeducation.
Transfer of the flexor carpi ulnaris to the extensor digitorum communis will provide extensor function of the fingers, as it has adequate power and excursion and takes advantage of the linkage between wrist flexion and finger extension. Other typical tendon transfers for finger extension in radial nerve palsy include the flexor carpi radialis and the flexor digitorum superficialis.
The brachioradialis is a radial nerve innervated muscle and will not be functioning in this patient who has a high radial nerve palsy. In low radial nerve palsies, it can be used to restore thumb extension. The brachioradialis can also be used to restore finger or wrist extension, as well as finger or thumb flexion in the appropriate patient.
The extensor carpi radialis longus is not functional in this patient with radial nerve palsy. It can be used as a transfer for finger flexion in the appropriate patient.
The palmaris longus does not have sufficient power to provide finger extension. It can be used as a transfer for thumb extension.
The pronator teres has adequate power but less excursion. It is typically used to restore wrist extension rather than finger extension.
A 30-year-old woman comes to the office because of a laceration of the dorsal long finger extensor tendon. Physical examination shows extension of all fingers to zero degrees at the metacarpophalangeal joint. Which of the following structures provides extension force that explains this exam finding?
A) Deep transverse metacarpal ligament
B) Intact paratenon
C) Interosseous muscles
D) Juncturae tendinum
E) Lumbrical muscles
The correct response is Option D.
Juncturae tendinum are tendon-like bands that connect the long, ring, and little finger extensor digitorum communis tendons. If the long finger extensor tendon is lacerated proximal to the attachment of the juncturae tendinum between the long and ring fingers, the ring finger extensor digitorum communis tendon will apply extension force to the distal long finger extensor tendon via the juncturae tendinum and produce metacarpophalangeal (MCP) extension.
Interossesous and lumbrical muscles produce flexion of the MCP joint. The deep transverse metacarpal ligament stabilized the metacarpal heads relative to each other but does not produce motion at the MCP joint. In this patient, the tendon is visible and noted to be completely lacerated; therefore, the paratenon is not intact.
A 15-year-old boy is brought to the emergency department because he felt a “pop” followed by acute pain in his left ring finger while grabbing an opposing player’s jersey during a rugby match. Physical examination shows pain, tenderness, and swelling over the volar aspect of the finger, from the area of the distal interphalangeal joint flexor crease to the proximal interphalangeal (PIP) joint crease. The distal phalanx rests at neutral and no active flexion is possible. The patient can flex at the PIP with minimal discomfort. Which of the following is the most appropriate management?
A) End-to-end flexor tendon repair
B) Flexor tendon reinsertion
C) Open reduction and pin fixation of the middle phalanx
D) Splinting, followed in 2 weeks by range-of-motion exercises
E) Tendon transfer
The correct response is Option B.
The scenario described provides a classic example of a distal flexor tendon avulsion. Because of several potential factors, the ring finger is the most common finger to present with this type of injury. The flexor digitorum profundus of the ring finger has a less robust insertion at the distal phalanx than the long finger, which is a tip-off in the vignette for this classic injury. Yet the ring finger is similarly involved in the type of hyperextension force, or resisted flexion force, which generates this injury. The little finger does not present as much with this injury either.
Flexor tendon reinsertion is correct, because the indicated management is early operation and reinsertion, if possible, of the avulsed tendon. This can be accomplished in a variety of ways, but that discussion is not central to the question.
Splinting, followed in 2 weeks by range-of-motion exercises is wrong, because that answer describes how one might treat a sprain, which this is not. If one treated the tendon avulsion conservatively, and incorrectly, by splinting, the surgeon would lose the window for early repair, and the outcome for the patient would be poor. Secondary or delayed reconstruction in these cases is often not possible, and when possible, they often have results inferior to immediate repair.
Tendon transfer is wrong because tendon transfers are not used for immediate repair of flexor avulsions. Tendon transfers are useful for secondary reconstruction in nerve palsies, for example. But they are not relevant to this distal and acute injury, confined to a single digit.
Open reduction and pin fixation of the middle phalanx is wrong because the injury is not a fracture of the middle phalanx. It is true that one form of the flexor avulsion can involve an avulsion fracture off of the volar aspect of the distal phalanx, and that reinsertion of the fragment is part of the repair. But flexor tendon avulsion does not involve fracture of the middle phalanx. Furthermore, this is not an avulsion of the flexor digitorum sublimis because the patient flexes at the PIP with minimal discomfort, as per the vignette.
End-to-end flexor tendon repair is wrong because this injury is a tendon avulsion from a distal bony insertion. There is no distal tendon to which to perform an end-to-end repair. Successful repair of a flexor digitorum profundus (FDP) avulsion really requires some form of anchoring of the distal FDP to distal phalanx bone.
An 80-year-old woman comes for evaluation because she is unable to flex the tip of the little finger of her nondominant hand 9 months after sustaining a laceration from a knife. She did not seek treatment at the time of injury. She has no pain or any difficulty with activities of daily living. Physical examination shows a well-healed laceration over the volar aspect of the middle phalanx. Active range of motion is full in the metacarpophalangeal and proximal interphalangeal (PIP) joints; there is no flexion at the distal interphalangeal joint. Which of the following is the most appropriate management?
A) Delayed primary flexor digitorum profundus repair
B) Flexor digitorum superficialis transfer
C) PIP joint arthrodesis
D) Staged flexor tendon reconstruction with placement of a silicone rod followed by tendon grafting
E) No intervention is indicated
The correct response is Option E.
No intervention is indicated for this patient. The principles of tendon repair and reconstruction have evolved since the first description of primary tendon repair in Zone II in 1967. Proper patient selection is essential before attempting any reconstruction to restore functional motion.
The indications for grafting or reconstructing through an intact flexor digitorum superficialis (FDS) are narrow, and sacrifice of an intact FDS is generally not recommended. Most of the functional arch of motion is maintained with the superficialis tendon, and many patients will function well with an FDS digit alone. Profundus reconstruction through an intact FDS is most often reserved for patients between 10 and 21 years old with high occupational demands for dexterity such as artists or musicians. This patient is beyond the recommended age range for an optimal outcome and is reporting no functional deficits as a result of her injury. In addition, delayed symptoms may give a clue to the patient’s ability to comply with rigorous postoperative therapy.
Delayed primary repair can be attempted up to several weeks after a flexor tendon injury, and up to 6 weeks in pediatric patients. However, 9 months is well beyond the time when a primary repair would be possible. The FDS from an adjacent finger can be used as the proximal motor in cases of tendon graft reconstruction or tendon repair rupture. This is a consideration if the native proximal stump of the profundus is significantly damaged or scarred and has poor excursion. In this patient, reconstruction is not indicated, and nothing is mentioned regarding the proximal tendon.
A distal interphalangeal (DIP) joint arthrodesis may be indicated if the DIP joint is unstable with a well-functioning proximal interphalangeal (PIP) joint. Tenodesis of the flexor digitorum profundus stump is another option for soft-tissue DIP stabilization.
Tendon reconstruction is indicated when a delay in treatment makes primary tendon repair impossible. A healed wound with full passive range of motion, absence of significant scarring, and an intact flexor retinacular pulley system are considered prerequisites for a single-stage reconstruction. In any other situation, a two-stage reconstruction with implantation of a temporary silicone rod is indicated. This would be the reconstructive strategy of choice for this patient if the FDS tendon were also involved in the original injury.
A 25-year-old man is scheduled to undergo muscle transfer with the gracilis muscle to restore finger flexion. To optimize function, the muscle should be inset under which of the following?
A) Less tension than it was in the leg
B) The same tension as it was in the leg
C) More tension than it was in the leg
D) No tension
The correct response is Option B.
Functional muscle transfers are a way to restore motion that has been lost. The gracilis muscle is a common option for this kind of transfer. To optimize the outcome, the muscle should be inset at the same tension it was under in the leg.
The physiologic basis for this technique is that muscle fibers function best at a particular length/tension relationship. Muscles are typically under ideal tension in their donor position. When transferred, a muscle can be placed under too much or too little tension. If a muscle is overstretched, there is little overlap of the actin and myosin units, and the contractile force is weak. If the muscle is under too little tension, the actin and myosin units aren’t able to achieve maximal contraction. Insetting a muscle under no tension produces the same result as insetting it under less tension.
A 25-year-old woman presents with a Zone II laceration of the left index finger flexor digitorum superficialis (FDS) and flexor digitorum profundus (FDP). Repair of the FDP and only one slip of FDS is planned. Compared with repairing both slips of FDS, repair of only one slip of the FDS will result in a decrease of which of the following?
A) Range of motion
B) Rate of tendon healing
C) Resistance
D) Risk for infection
E) Strength of FDP repair
The correct response is Option C.
There is a close proximity of the flexor digitorum superficialis (FDS) and flexor digitorum profundus (FDP) tendons in Zone II lacerations. Due to this, adhesion formation is common after injury. Repairing only one slip of the FDS tendon allows for more room within Camper chiasm during motion, which has been found to decrease resistance and improve glide during motion. It has also not been found to limit active range of motion when compared with repairing both FDP and FDS in Zone II. Due to the improvement in glide and decreased resistance, fewer adhesions occur. This also decreases the work of flexion as well. Due to increased adhesion formation with repair of both FDP and FDS in Zone II, there is an increased rate of secondary surgeries for tenolysis. There is no change in the risk for infection or change in the rate of tendon healing with this type of repair compared with repairing both slips of FDS.
A 35-year-old woman who is an artist is evaluated because of Boutonnière deformity with a flexed proximal interphalangeal (PIP) joint and an extended distal joint. She reports sustaining a laceration from a paint knife to the nondominant midline dorsal PIP joint 6 months ago. She did not seek medical attention at the time of injury. This patient’s deformity is a result of attenuation of which of the following structures?
A) Oblique retinacular
B) Sagittal bands
C) Terminal tendon
D) Triangular ligament
E) Volar plate
The correct response is Option D.
A Boutonnière deformity occurs with injury to the central tendon and injury or attenuation of the triangular ligament. The lateral bands migrate volarly to become proximal interphalangeal (PIP) joint flexors, and their action is on the distal interphalangeal (DIP) joint, extending it. The triangular ligaments are bound by the lateral bands, central slip, and terminal tendon.
The sagittal bands of the metacarpophalangeal (MCP) joint originate from the volar plate and anchor the extensor mechanism. The oblique retinacular ligament originates from the volar lateral crest of the proximal phalanx and inserts into the terminal tendon. The volar plates stabilize the MCP and PIP joints. The terminal tendon is the convergence to the lateral bands at the dorsum of the middle phalanx inserting on the distal phalanx.
A 54-year-old man is brought to the emergency department after sustaining a laceration of the right hand from a box cutter. Physical examination shows a laceration over the palmar proximal phalanx of the long finger. Complete laceration of the A2 pulley is found at exploration. If the pulley is not repaired, which of the following best describes how flexor tendon mechanics will be affected?
The correct response is Option C.
The moment arm of the joint refers to a perpendicular line drawn from the mid axis of the joint to the tendon causing movement in the joint. The moment arm represents torque and can be thought of as power at an individual joint. The system can be broken down into simpler terms by thinking of wrenches of different lengths. The longer the wrench, the greater the amount of power can be placed in the turning of a nut onto a bolt. The same applies to the joints of the hand. As the tendon itself gets farther away from the center of rotation of the joint (increased moment arm), there is an increase in the torque on that joint, and, in turn, the power acting upon the rotation of the joint. As a flexor tendon gets farther away from the PIP joint (increase in moment arm), for the same strength of pull, there is an increase in force to that joint. However, there is also a loss of efficiency because the excursion of the tendon needs to increase more and more as the tendon itself gets farther away from the axis of rotation. A greater amount of excursion is required to flex the joint through to a given angle. Therefore, only an increase in moment arm, decrease in PIP joint motion, and increase in power is an appropriate response. This has clinical significance in situations such as those presented in the scenario described. Cutting the A2 pulley allows the tendon to migrate farther in a palmar direction, or “bowstring” away, from the axis of rotation. This yields an increase in the moment arm, a decrease in tendon excursion, and, ultimately, an increase in power, with the loss of efficiency. The range of motion is decreased as the flexor tendons can no longer flex the joint fully. This effect is strongest in the A2 and A4 pulleys, which prevent bowstringing of the tendons at the proximal and middle phalanges, respectively.
A 46-year-old man is brought to the emergency department after sustaining an injury to the dominant right wrist. Examination shows a 6-cm-diameter wound on the dorsal surface of the wrist. Significant contamination of the wound and segmental tendon loss are noted. Neurovascular status is intact. The patient is unable to extend the index, long, and ring fingers. Which of the following is the most important next step in management?
A) Immediate coverage with a free flap and delayed tendon grafting
B) Irrigation and debridement of all contaminated and nonviable tissue
C) Placement of allograft tendons and skin substitutes
D) Primary repair of tendons
E) Primary single-stage tendon grafting and coverage with a groin flap
The correct response is Option B.
Severely contaminated wounds, open fractures, and joint capsule lacerations require emergent and thorough irrigation and debridement. Fractures and skin loss should be treated in the initial procedure when feasible. Fractures should be fixed rigidly enough to allow early dynamic splinting or active motion. For lacerations without associated injury, the extensor tendon can be repaired emergently or in a delayed primary fashion after irrigation, debridement, and loose closure of the wound. If the repair is delayed, it should be performed within 7 days before the tendon ends retract or soften.
The results of extensor tendon repair depend on the complexity of trauma and the anatomical zone of tendon injury. In general, results of primary extensor tendon repair are better in Verdan Zones I, II, IV, and V, and worse in Zones III and VI.
Tendons should not be repaired under tension as tendon force imbalance and tendon rupture will usually result. Tendon grafting should not be performed in a contaminated wound and probably should be staged in this situation if it is necessary because of tendon loss.
Surgical reconstruction of the oblique retinacular ligament is primarily used to treat which of the following?
A) Boutonnière deformity
B) Flexor digitorum profundus tendon avulsion
C) Sagittal band rupture
D) Scapholunate ligament injury
E) Swan-neck deformity
The correct response is Option E.
Spiral oblique retinacular ligament (SORL) reconstruction is used to address digital swan-neck deformity. The procedure is predicated on surgically recreating the proposed function of the oblique retinacular ligament (ORL); linking proximal interphalangeal (PIP) joint and distal interphalangeal (DIP) joint flexion and extension. The ORL arises from the flexor tendon sheath at the base of the proximal phalanx, extends distally and dorsally over the PIP joint, and fuses with the lateral extensor tendon. Because of the site of the ORL origin and insertion, PIP joint extension places the ORL under tension, which results in DIP joint extension. PIP joint flexion, however, decreases tension in the ORL and allows DIP joint flexion. Although anatomical studies are conflicting regarding the actual presence and function of the ORL, surgically recreating this proposed function has been used to treat swan-neck and mallet deformities. Thompson, Littler, and Upton described the dynamic SORL reconstruction in 1978 as an alternative to static techniques, such as transferring a single lateral band volarly to prevent PIP joint hyperextension. In a SORL reconstruction, a free tendon graft is fixated to the dorsal distal phalanx, passed over the radial aspect of the middle phalanx, and then “spiralled” palmarly across the PIP joint, where it is then secured to the ulnar aspect of the proximal phalanx.
A flexor digitorum profundus avulsion (i.e. Jersey finger) is typically managed by reinserting the tendon into the volar base of the distal phalanx. If delayed greater than 8 to12 weeks, interposition tendon reconstruction may be necessary. A boutonniere deformity generally occurs as a result of a central slip injury; this leads to a flexed posture of the PIP joint and an eventual hyperextended posture of the DIP joint as the lateral bands translate volarly. If closed, splinting is indicated. If the central slip was lacerated, an open repair is recommended. A sagittal band tear may cause pain and subluxation of the extensor mechanism at the MCP joint and can be treated with splinting or repair. A scapholunate ligament tear can be directly repaired if acute, or reconstructed using a variety of techniques in the absence of scapholunate advanced collapse and arthritis of the wrist. If arthritis has developed, then partial or total wrist fusion may be indicated.
A 53-year-old man comes to the office for evaluation of a flexion contracture at the proximal interphalangeal (PIP) joint of the left long finger three months after he sustained a volar dislocation. Immobilization immediately after the injury and a subsequent trial of aggressive hand therapy were unsuccessful in restoring passive extension of the joint. On physical examination, the PIP joint is in 40 degrees of flexion and cannot be passively extended. Surgical release of the PIP joint is performed with release of the checkrein ligaments and tenolysis of the flexor tendons. Postoperative examination shows a mild flexion deformity of the PIP joint and slight hyperextension of the distal interphalangeal joint. Which of following is the most likely cause of these findings?
(A) Adhesions of the flexor digitorum profundus tendon
(B) Adhesions of the flexor digitorum superficialis tendon
(C) Inadequate release of the checkrein ligaments
(D) Laxity of the extensor tendon
(E) Tightness of the ligament of Landsmeer
The correct response is Option E.
The oblique retinacular ligament of Landsmeer passes volar to the axis of rotation of the proximal interphalangeal (PIP) joint, and when it is involved in a fibrotic process, it may produce hyperextension of the distal interphalangeal (DIP) joint. Tightness of this ligament can result in contractural deformity resulting in a boutonnière deformity. Inadequate checkrein release would result in persistent flexion deformity at the PIP joint but would not impact the position of the DIP joint. Scar adhesions of the flexor tendons would limit active range of motion of the digit but would not create a hyperextension deformity at the DIP joint. Extensor tendon laxity would limit active extension at the DIP joint, creating a flexion deformity rather than a hyperextension deformity.
A 50-year-old woman comes to the emergency department after sustaining an avulsion injury of the right ring finger proximal interphalangeal (PIP) joint. A photograph is shown. Examination shows the central slip is disrupted, and the inside of the PIP joint is visible through the dorsal wound. The patient is able to actively extend the PIP joint. Which of the following anatomical structures allows the patient to extend the PIP joint?
A) Extrinsic extensor tendon
B) Interosseous muscle tendon
C) Lateral conjoined tendon
D) Oblique retinacular ligament
E) Sagittal band
The correct response is Option B.
The central slip of the extensor mechanism is the terminal direct extension of the extrinsic extensor tendon (extensor digitorum communis and extensor digiti quinti) and is the primary extensor of the proximal interphalangeal (PIP) joint. Injury to the central slip will normally produce flexion of the PIP joint due to unopposed action of the flexor digitorum superficialis (FDS) and flexor digitorum profundus (FDP) tendons and is called a boutonniere deformity.
The intrinsic extensor mechanism, via the middle band of the interosseous muscles, also inserts on the dorsal base of the middle phalanx and causes extension of the PIP joint. In an open injury, the central slip may be injured without concurrent injury to the interosseous muscle tendon, allowing the patient to still actively extend the PIP joint even in the presence of a disruption of the central slip.
The oblique retinacular ligament connects the flexor tendon sheath volarly to the terminal extensor tendon dorsally. When a patient sustains a laceration to the extensor mechanism over the body of the middle phalanx bone, the oblique retinacular ligament may prevent the occurrence of an extensor lag and a mallet deformity.
The lateral conjoined tendon is formed by the lateral bands of the interosseous muscles and the lateral slips of the extrinsic extensor and produces extension of the distal interphalangeal (DIP) joint.
The sagittal band keeps the extrinsic extensor tendon centralized over the dorsal metacarpophalangeal (MP) joint by connecting to the volar plate. Disruption of the sagittal band on one side of a finger would allow the extrinsic extensor tendon to dislocate and impair its ability to extend the MP joint.
A 35-year-old man has clawing of all four fingers of the right hand 2 years after repair of a forearm laceration that injured the median and ulnar nerves. Photographs are shown. Both nerves were repaired shortly after the injury. All fingers have full passive range of motion. An extensor carpi radialis longus transfer is planned to correct the clawing of all four fingers. Which of the following donor sites is most likely to provide sufficient tendon graft for this procedure?
A) Abductor digiti quinti
B) Extensor digitorum longus
C) Flexor digitorum superficialis of the long finger
D) Palmaris brevis
E) Pronator teres
The correct response is Option B.
The Brand transfer uses the extensor carpi radialis longus or brevis as a donor motor to correct clawing of the fingers. It can be used to correct ulnar (ring and small finger) clawing or clawing of all four fingers. In either case, a tendon graft is needed to bridge the gap between the native distal limit of the extensor carpi radialis longus or brevis (on the index or long finger metacarpal base, respectively) to the transfer insertion on the lateral band at the proximal phalanx level. The transfer can be passed through the interosseous membrane in the forearm and then through the carpal tunnel or the intermetacarpal spaces in the hand. The transfer must pass volar to the deep transverse metacarpal ligament to have the correct vector of pull.
The extensor digitorum longus provides four tendon slips distally, each with its own paratenon, but has one tendon coming off the muscle proximally. A photograph is shown. There is minimal donor site morbidity in the foot due to the retained function of the extensor digitorum brevis.
Palmaris brevus has no tendon and cannot be used as a graft donor.
Abductor digiti quinti can be used as a donor muscle for thumb opposition transfer, most commonly in children. It has a very short tendon and cannot be used for anti-claw transfers. In addition, due to this patient’s injury, the abductor digiti quinti is likely denervated and would not be functional for a transfer.
Flexor digitorum superficialis (FDS) of the long finger can be used for anti-claw transfers. The tendon can be split along the plane of Camper’s chiasm to create two distal slips for insertion. It is well suited as an anti-claw transfer in patients with isolated ulnar nerve palsy. The FDS tendon cannot be split into four slips for insertion, as would be needed in this patient, and the power of one FDS muscle is insufficient to correct clawing in four fingers. In addition, the FDS resides superficial to the median nerve. In a patient who sustained a forearm laceration with injury to the median nerve, the overlying FDS is also likely to have been injured.
Pronator teres is the most common donor motor to restore wrist extension in patients with radial nerve palsy. It has a very short tendon and is not used for anti-claw transfers.
A 28-year-old woman comes to the office for follow-up examination after six weeks of splinting to correct a closed injury without fracture of the right index finger (shown). Despite instructions to wear the splint at all times, the patient says she has been taking it off when she showers and when she types at work because it gets in the way. Which of the following is the most appropriate next step in management?
A) Splinting for an additional six weeks
B) Transarticular fixation with Kirschner wires
C) Central slip tenotomy
D) Open repair with direct suturing of the terminal tendon
E) Fusion of the distal interphalangeal joint
Correct answer is option B.
This patient has a mallet finger deformity. No fracture was involved; therefore, it is considered a Type I mallet injury. Patients are sometimes noncompliant or not well instructed regarding how the splint is to be used. Both the Fowler tenotomy and open repair should be reserved for chronic cases of mallet finger. In fact, open repair with direct suture of the terminal tendon has shown poor results. Fusion of the distal interphalangeal joint is an extreme method of treating this condition and would not be indicated at this time. An additional six-week period of splinting would be appropriate in a compliant patient. One author has shown that mallet fingers that remain untreated for up to 12 weeks can be treated conservatively with six weeks of splinting. However, a noncompliant patient would benefit from transarticular fixation with Kirschner wires, which would be more difficult to manipulate versus splinting alone.
A 30-year-old man who works as an executive presents with a Zone II flexor tendon laceration. He undergoes immediate four-strand core suture flexor tendon repair and epitendinous suture. In the early postoperative period, which of the following approaches is recommended to optimize the outcome in this patient?
The correct response is Option B.
Advances in primary flexor tendon repair techniques and postoperative mobilization protocols have improved functional results for Zone II injuries. Repair strength has been shown to be related to the number of strands that cross the repair site. Other factors that contribute to repair strength include suture caliber, adequate core suture purchase (at least 0.7 to 1.0 cm), and the use of an epitendinous repair in addition to core suture placement. A forearm-based dorsal block splint is placed to protect flexor tendon repairs. Compared with passive mobilization protocols, early active mobilization protocols demonstrate better functional outcomes without a significantly increased rate of tendon rupture. A minimum of a four-strand core repair is necessary to tolerate an early active mobilization protocol. In this patient, a six-strand core repair with an epitendinous repair is appropriate for an active motion protocol. Although the flexor repair described in this scenario is strong enough to tolerate protected early active motion, complete absence of a protective splint with unrestricted use of the hand would be inappropriate and risks tendon rupture. The Kleinert splint is a dorsal extension block splint that allows active extension and utilizes rubber bands for passive flexion. This is not considered an early active flexion protocol. A relative motion extension splint with immediate controlled active motion is used following extensor tendon repairs/injuries. Cast immobilization following flexor repair would not be appropriate in this scenario if the goal is to maximize flexor function, but it may have a role in the postoperative management of flexor injuries in children or unreliable adults.
A 28-year-old woman is brought to the emergency department after sustaining an injury to the arm during a motor vehicle collision. A photograph is shown. Physical examination shows inability to extend the index or long fingers, and a rent in the dorsal wrist capsule. Which of the following extensor zones is most likely involved?
A) II
B) III
C) IV
D) V
E) VI
The correct response is Option E.
The patient described sustained a dorsal wrist injury involving extensors of the wrist and fingers, with the injury at the base of the hand and over the carpus. Typically this is considered zones VI and VII. The other zones represent the following areas with some common conditions listed for each zone. Knowing and reporting zones of injury are helpful not just for descriptive purposes, but also for communicating with other doctors and therapists. Common therapy protocols are based on which zone or zones are involved in the injury.
Which of the following Zone II four-strand flexor tendon repair configurations demonstrates the greatest overall fatigue strength and gap resistance in biomechanical testing?
The correct response is Option A.
Increasing the suture caliber has shown to increase the force in static testing and fatigue strength in dynamic testing. The use of 3-0 polyethylene terephthlate fiber suture increased the fatigue strength compared with 4-0 sutures by two to three times.
The placement of the suture dorsally has been shown to increase the strength of the repair by two to four times, and is more environmentally favored because of a decreased risk for interference with the synovial fluid.
It has been shown that locking loops improve force and gap resistance compared with grasping loops in flexor tendon repair. Statistically significant improvement was observed with the locking loop technique for ultimate and gap strength values using 2-0 core suture and ultimate strength values using 3-0 core suture.
A 44-year-old woman sustained a second-degree burn to the volar surface of the wrist and palm. She is sent to occupational therapy for fabrication of a splint, placing the wrist and fingers in an intrinsic plus position. Which of the following best describes the position of the wrist and fingers in this splint?
The correct response is Option C.
The position of safe immobilization (POSI), also called the intrinsic plus position, was described initially by J.I.P. James (British orthopedic surgeon) and is recognized as the correct position in which to immobilize the hand safely following injury or surgery. The wrist is placed in 0 to 30 degrees of extension, metacarpophalangeal (MCP) joints in 70 to 90 degrees of flexion and interphalangeal (IP) joints in full extension. This position creates pretension on the collateral ligaments of the wrist and the MCP and IP joints of the hand, thereby decreasing the risk of stiffness and contracture.
A 28-year-old woman comes to the office for follow-up examination after six weeks of splinting to correct a closed injury without fracture of the right index finger (shown). Despite instructions to wear the splint at all times, the patient says she has been taking it off when she showers and when she types at work because it gets in the way. Which of the following is the most appropriate next step in management?
(A) Splinting for an additional six weeks
(B) Transarticular fixation with Kirschner wires
(C) Central slip tenotomy
(D) Open repair with direct suturing of the terminal tendon
(E) Fusion of the distal interphalangeal joint
The correct response is Option B.
This patient has a mallet finger deformity. No fracture was involved; therefore, it is considered a Type I mallet injury. Patients are sometimes noncompliant or not well instructed regarding how the splint is to be used. Both the Fowler tenotomy and open repair should be reserved for chronic cases of mallet finger. In fact, open repair with direct suture of the terminal tendon has shown poor results. Fusion of the distal interphalangeal joint is an extreme method of treating this condition and would not be indicated at this time. An additional six-week period of splinting would be appropriate in a compliant patient. One author has shown that mallet fingers that remain untreated for up to 12 weeks can be treated conservatively with six weeks of splinting. However, a noncompliant patient would benefit from transarticular fixation with Kirschner wires, which would be more difficult to manipulate versus splinting alone.
An 18-year-old female gymnast comes to the office because of the sudden onset of pain, swelling, and ecchymosis of the right ring finger that began 3 days ago while she was practicing hand-only climbing on a rock-wall. Physical examination shows tenderness over the palmar aspect of the finger at the proximal phalanx. Isolated flexion at the distal interphalangeal joint and flexion of the digit at the proximal interphalangeal joint while the remaining digits are held in hyperextension are intact. The patient can fully flex and extend the finger, and the proximal interphalangeal joint is stable to stress. X-ray study is shown. Which of the following is the most likely cause of the findings in this patient?
A) Avulsion of the flexor profundus tendon insertion
B) Dislocation of the proximal interphalangeal joint
C) Rupture of the A2 pulley
D) Stenosing tenosynovitis
E) Volar plate avulsion fracture
The correct response is Option C.
Stenosing tenosynovitis (trigger finger) typically results in pain over the metacarpophalangeal (MCP) joint associated with crepitation, clicking, or locking of the digit with altered motion during the flexion-extension arc.
Dislocation of the proximal interphalangeal (PIP) joint could account for the symptoms; however the imaging shows the joint to be congruent and the exam did not reveal any instability.
An injury originally identified in rock climbers, rupture of the A2 pulley has been increasingly recognized in other sports and activities. The forceful flexion of the flexor profundus and superficialis tendons with the PIP joint flexed 90 degrees and the distal interphalangeal (DIP) joint extended (the “crimp” position) placed loads exceeding the tolerance of the A2 across the palmar PIP joint, resulting in rupture of the underlying pulley. Treatment for an isolated pulley injury includes rest, ice, anti-inflammatory drugs, and external support through use of a ring splint.
Avulsion of the profundus tendon (jersey finger) typically presents with loss of flexion of the DIP joint. Pain may be present both at the avulsion site and over the retracted end of the tendon. This patient’s examination shows the profundus function to be intact.
Volar (palmar) plate avulsion injuries present with pain and swelling at the PIP joint, but the joint will often be painful to stress in hyperextension and potentially, if the injury extends dorsally into the collateral ligaments, it may exhibit instability. X-ray imaging often demonstrates a small bony avulsion fragment (absent in this patient) along the palmar PIP joint.
A 25-year-old woman comes to the office for consultation regarding an injury to the left thumb (shown). During surgical repair of this injury, which of the following is the sequence in which anatomic structures will be encountered?
(A) Abductor pollicis, flexor pollicis longus, volar plate
(B) First dorsal interosseous, oblique pulley, volar plate
(C) Junctura tendineum, extensor pollicis longus, collateral ligament
(D) Sagittal bands, adductor aponeurosis, collateral ligament
(E) Skin, ulnar collateral ligament, volar plate
The correct response is Option D.
This patient has an ulnar collateral ligament injury of the thumb metacarpophalangeal (MP) joint. Although the indications for surgical repair are controversial, the pertinent anatomy is consistent. After the skin and subcutaneous tissue are divided, the sagittal bands are encountered. The sagittal bands stabilize the extensor pollicis longus over the MP joints of the thumb and travel from the lateral aspects of the tendon towards the flexor digital sheath. Repair of this structure is important to prevent subluxation of the tendon with thumb motion.
The adductor for aponeurosis is readily visible under the sagittal bands. This structure should also be tagged before division to facilitate accurate surgical repair. Once the adductor aponeurosis is divided, the ulnar collateral ligament is readily visible and amenable to repair.
The juncturae tendineum are extensor tendon connections on the dorsum of the hand and are not involved with the regional anatomy of the thumb. The extensor pollicis longus is usually dorsal to the area of dissection and does not require surgical manipulation.
The ulnar collateral ligament does not exist under the skin. The volar plate may be injured in a gamekeeper=s type of injury and should be assessed. A clue to a significant volar plate injury requiring repair is volar subluxation of the proximal phalanx in relation to the metacarpal.
The abductor pollicis, flexor pollicis longus, and first dorsal interosseous are out of the zone of injury and should not be surgically disturbed.
A 45-year-old man has a mass in the left volar forearm. An MRI is shown. Oncologic resection will involve removing all muscles of the anterior forearm compartment. Which of the following techniques is most appropriate to reconstruct finger flexion postoperatively?
A) Flexor digitorum profundus to superficialis transfer
B) Flexor pronator slide
C) Free gracilis innervated by a median nerve branch
D) Oberlin-Mackinnon nerve transfer
E) Pedicled latissimus dorsi muscle flap transfer
The correct response is Option C.
A free gracilis muscle would provide a good strength and excursion match to the native finger flexors it would replace. Vascular and nerve connections could be performed in the distal upper arm, outside of the zone of resection. While individual finger flexion would not be restored, the patient would be able to make a composite fist after this surgery.
The flexor digitorum profundus to superficialis transfer is used to treat flexor spastic contracture, typically with palmar hygiene issues, in a patient who still has some voluntary motor control. It requires the presence of flexor digitorum profundus and superficialis muscles, both of which would be removed as part of the anterior forearm compartment muscles.
The Oberlin-Mackinnon nerve transfer transfers branches of the median nerve and ulnar nerve to the brachialis and biceps muscles, respectively. It is used to restore elbow flexion and would not provide finger flexion.
A flexor pronator slide detaches the muscles originating from the medial epicondyle of the humerus and advances them distally. It is used to treat contractures of the fingers, often in patients with mild to moderate Volkmann contracture. In this patient, the flexor muscles have been resected, so this procedure is not possible.
A latissimus dorsi muscle provides broad soft-tissue coverage for wounds and can also provide a strong flexion force. It cannot reach beyond the distal elbow. It can restore elbow flexion but cannot be used as a pedicled transfer to restore finger flexion.
A 53-year-old man comes to the office for evaluation of a flexion contracture at the proximal interphalangeal (PIP) joint of the left long finger three months after he sustained a volar dislocation. Immobilization immediately after the injury and a subsequent trial of aggressive hand therapy were unsuccessful in restoring passive extension of the joint. On physical examination, the PIP joint is in 40 degrees of flexion and cannot be passively extended. Surgical release of the PIP joint is performed with release of the checkrein ligaments and tenolysis of the flexor tendons. Postoperative examination shows a mild flexion deformity of the PIP joint and slight hyperextension of the distal interphalangeal joint. Which of following is the most likely cause of these findings?
A) Adhesions of the flexor digitorum profundus tendon
B) Adhesions of the flexor digitorum superficialis tendon
C) Inadequate release of the checkrein ligaments
D) Laxity of the extensor tendon
E) Tightness of the ligament of Landsmeer
Correct answer is option E.
The oblique retinacular ligament of Landsmeer passes volar to the axis of rotation of the proximal interphalangeal (PIP) joint, and when it is involved in a fibrotic process, it may produce hyperextension of the distal interphalangeal (DIP) joint. Tightness of this ligament can result in contractural deformity resulting in a boutonnière deformity. Inadequate checkrein release would result in persistent flexion deformity at the PIP joint but would not impact the position of the DIP joint. Scar adhesions of the flexor tendons would limit active range of motion of the digit, but would not create a hyperextension deformity at the DIP joint. Extensor tendon laxity would limit active extension at the DIP joint, creating a flexion deformity rather than a hyperextension deformity.
A 45-year-old, left-hand–dominant man presents to the emergency department with right thumb pain after a fall while hiking. X-ray studies are shown. Physical examination shows the thumb is swollen, bruised, and tender to palpation. The metacarpophalangeal joint demonstrates laxity of 40 degrees with a firm endpoint on valgus testing. To determine if nonoperative management is an option, which of the following additional tests should be ordered?
A) Arthrography
B) CT scan
C) Electrodiagnostic studies
D) Triple-phase bone scan
E) Ultrasonography
The correct response is Option E.
An ultrasound will be the most effective way to diagnose a Stener lesion, which would necessitate surgical intervention for this patient. Stener lesions are a unique type of ulnar collateral ligament injury in which the dorsal adductor aponeurosis becomes interposed between the ruptured distal end of the ligament and its insertion at the proximal phalanx. This prevents healing of the ligament, and thus these injuries cannot be treated closed. Ulnar collateral ligament injuries that demonstrate no endpoint on valgus stress testing generally require operative management. Those that demonstrate some laxity with a firm endpoint can be treated with cast immobilization as long as there is no Stener lesion. Stress view x-ray study will show full versus partial disruption of the ligament but will not identify the presence or absence of a Stener lesion. Some consider MRI to be the most sensitive modality for detection of these lesions; however, criticisms of MRI include its cost and delay in availability. Arthrography can be used to identify capsular injury but cannot detect the collateral ligament displacement with high accuracy. CT scan will not be able to resolve the ligament position clearly. Ultrasonography is cost-effective, dynamic, and easy to obtain. Ultrasonography has been shown to have a positive predictive value of 87 to 100% when used to identify Stener lesions. On the imaging examination, an uninjured collateral ligament will appear as a hypoechoic arc. In a Stener lesion, the arc will be disrupted with displacement or a large gap between the two ends, as seen in the image.
A 35-year-old, right-hand-dominant man comes to the office because of passively correctable clawing of all four fingers of the right hand 1 year after he sustained a stab wound to the proximal right forearm that lacerated the ulnar nerve and artery, median nerve, flexor digitorum superficialis (FDS), flexor digitorum profundus, flexor carpi radialis (FCR), and flexor carpi ulnaris (FCU). Each of the injured structures was repaired primarily on the day of injury. A photograph is shown. Which of the following tendons is the most appropriate donor to address the clawing deformity?
A) Abductor pollicis brevis
B) Brachioradialis
C) Extensor carpi radialis brevis
D) FCRbr> E) FDS-3 to the long finger
The correct response is Option C.
The flexor digitorum superficialis and flexor carpi radialis musculotendinous units were lacerated in the original injury. They would not be appropriate donor motors due to this. Brachioradialis transfer to the flexor pollicis longus transfer has been reported for patients with cervical spine injuries, but it is not used for transfers to restore intrinsic muscle function. The abductor pollicis brevis cannot be used to correct a claw deformity due to its small size and position in the thenar eminence; in addition, for this patient, its innervation was injured in the original trauma.
Both the extensor carpi radialis longus and brevis have been described as a tendon transfer. Neither muscle has been affected by the initial injury. Whichever tendon is not harvested can power wrist extension along with the extensor carpi ulnaris. The tendon does need to be elongated with a graft.
A 30-year-old man comes to the emergency department after sustaining a laceration of the palm of the left hand from a knife. He reports difficulty flexing the ring finger of the left hand. A photograph is shown. Which of the following is the most appropriate method to clinically assess the integrity of the flexor digitorum superficialis tendon?
A) Hold the distal interphalangeal joint of the ring finger in extension and ask the patient to flex
B) Hold the index, long, and little fingers in extension and ask the patient to flex
C) Hold the long, ring, and little fingers flexed at the metacarpophalangeal (MCP) joint and ask the patient to flex
D) Hold the MCP joints of the index, long, and little fingers in flexion and ask the patient to extend
E) Hold the ring finger extended at the MCP joint and ask the patient to flex
The correct response is Option B.
The flexor digitorum superficialis (FDS) tendon flexes the proximal interphalangeal (PIP) joint. The flexor digitorum profundus (FDP) tendon can also flex the PIP joint, in addition to flexing the distal interphalangeal (DIP) joint. To confirm that the FDS tendon is flexing the PIP joint, FDP motion must be excluded.
The FDP tendons to the long, ring, and little fingers share a common muscle belly. Thus, holding the long and little fingers in extension will prevent the FDP to the long, ring, and little fingers from firing. Any flexion of the PIP joint of the ring finger must then be caused by the FDS tendon.
Holding the DIP joint of the ring finger in extension will prevent DIP flexion. It will not, however, prevent the pull of the FDP tendon from being transmitted to the PIP joint.
Holding the long, ring, and little fingers flexed at the MCP joint will not exclude FDP motion.
Holding the MCP joint of the ring finger extended will not exclude FDP motion.
Asking the patient to extend will not assess the integrity of a flexor tendon such as the FDS.
An otherwise healthy 32-year-old woman returns to the emergency department because she is unable to use her right hand 20 days after she underwent wound closure for management of a laceration to the hand. A photograph of the patient attempting to make a fist is shown. On examination, there is decreased sensation in the ulnar distribution, and the hand is warm. Which of the following tests is likely to provide the most pertinent information in developing a treatment plan for this patient’s injury?
A) CT angiography
B) Electromyography/nerve conduction study
C) Magnetic resonance angiography
D) Ultrasonography
E) No testing is necessary; physical findings are sufficient
The correct response is Option E.
The patient described has a significant wrist injury until proven otherwise. Physical examination will be the most helpful in making a determination regarding what should be done next. Electromyography/nerve conduction study typically does not give actionable information until 3 weeks or more after injury. Ultrasonography may be helpful but would not give more information than one could get from a thorough physical examination and would likely be painful as the probe is pressed on the wound. CT angiography can be critical preoperatively if there was a concern regarding inflow. Magnetic resonance angiography would be revealing but would be expensive and unnecessary in this setting.
The patient was taken to the operating room for exploration. Intraoperative and postoperative images are shown.
A 50-year-old woman comes to the emergency department because of a stab wound to the right forearm. A photograph is shown. She is taken to the operating room and general anesthesia is administered. Which of the following is the most appropriate examination, in this intubated patient, to assess for tendinous injuries to the fingers?
A) Passively extend the fingers
B) Passively extend the wrist
C) Passively flex the fingers
D) Passively flex the wrist
E) Place hand in cold water
The correct response is Option D.
This patient has sustained a dorsal mid forearm laceration. Common injuries within this location include injuries to the musculotendinous units of the extensors to the wrist, fingers, and thumb. Additionally, the radial sensory nerve and dorsal branch of the ulnar nerve could be injured depending on the location and vector of the object that caused the injury. Passive flexion as demonstrated in the photograph demonstrates the effect of tenodesis. With passive wrist flexion, intact digital extensors should be put under tension and bring the metacarpophalangeal joints into extension. However, in this patient the long and ring fingers do not extend with wrist flexion.
In an uninjured hand, when the wrist is passively flexed the fingers and thumb will extend. With wrist extension, the fingers are brought into flexion and the thumb is brought toward the small finger.
Bringing the wrist into extension would help with a volar wound as it would help establish injuries to digital flexors.
Putting the hand in cold water is a better test for sensory nerve injury as loss of wrinkling will be demonstrated.
Passive flexion or extension of the fingers will not reliably demonstrate which specific tendons are injured in this patient.
A 35-year-old woman is evaluated 2 months after repair of volar lacerations to the dominant ring and long fingers at Zone III in both digits. Physical examination shows both fingers have no active flexion. There is normal passive motion and normal sensation at the fingertips of the affected digits. Surgical exploration shows transsection of the tendons at both levels and 2-cm segmental tendon loss, but no tendon sheath scarring. Which of the following is the most appropriate management?
A) One-stage tendon grafting
B) Primary tendon repair
C) Primary tendon repair with z-lengthening
D) Superficialis to profundus tendon transfer
E) Two-stage tendon grafting
The correct response is Option A.
Several conditions must be met for single-stage tendon grafting to be successful. These include a hand and finger that have good passive motion, a well-healed wound with minimal scarring, and a digit that has intact nerves and arteries. This is a Boyes grade 1 injury.
If the grade of injury is greater than 1, two-stage grafting should be considered with implantation of a silicone rod and additional treatment to manage the other conditions to increase motion and function, such as joint release or reconstruction for loss of motion, nerve repair/reconstruction, and pulley reconstruction.
A primary repair is not going to be possible in this instance. Two-stage tendon grafting should be considered but a single stage graft can have excellent results with only one procedure. A tendon transfer is not appropriate for this situation.
A 53-year-old woman comes to the office because of pain of the dorsum of the left wrist and thumb for the past 3 months. The patient reports that pain occurs with activity. Physical examination shows pain is increased with passive wrist ulnar deviation with the thumb held in the palm and during resisted extension of the thumb metacarpophalangeal (MCP) joint. Axial loading of the thumb does not reproduce pain. An x-ray study is shown. Which of the following is the most likely diagnosis in this patient?
A) Basal joint arthritis
B) de Quervain tenosynovitis
C) Intersection syndrome
D) Scaphotrapezial arthritis
E) Stenosing tenosynovitis
The correct response is Option B.
Pain in the dorsal radial aspect of the wrist can be caused by a variety of conditions; a thorough history and physical examination are key to elucidating the correct diagnosis. In the scenario presented, the patient has a positive Finkelstein test along with reproduction of the pain with resistance to the extensor pollicis brevis muscle. These are classic findings of de Quervain tenosynovitis. The patient’s physical examination points to the first dorsal compartment of the wrist as a source of pathology rather than basal joint or scaphotrapezial arthritis. Radiographs have not been shown to correlate with symptomatology in basilar joint arthritis. Intersection syndrome is a tendinopathy between the intersection of the tendons of the first and second dorsal compartments. The pain of intersection syndrome is generally found more proximally in the forearm and is also increased with resisted wrist extension. Digital flexor tenosynovitis or trigger finger is an inflammatory tendinopathy of the flexor pollicis longus tendon and pain is generally reproduced with resisted thumb flexion.
A 17-year-old high school football player is unable to extend the proximal interphalangeal (PIP) joint of the ring finger two weeks after jamming the finger during a football game. Current physical examination shows hyperextension of the distal interphalangeal (DIP) joint with flexion of the PIP joint. There is full passive range of motion of the finger. Radiographs are unremarkable. Which of the following is the most appropriate initial management?
A) Extension splinting of the DIP joint
B) Extension splinting of the PIP joint
C) Extension splinting of the DIP and PIP joints
D) Closed reduction and percutaneous pin fixation of the PIP joint
E) Open repair of the central slip
This patient has a boutonniere deformity, in which the extensor mechanism (comprised of the central slip, transverse and oblique retinacular ligaments, and lateral bands) becomes imbalanced. In patients with this deformity, the central slip is damaged and the transverse retinacular ligament is stretched. The lateral bands begin to drift volarly (around days 10-21), eventually moving anterior to the center of rotation of the proximal interphalangeal (PIP) joint. As a result, the lateral bands flex the PIP joint, and passive extension of the PIP joint becomes impossible.
There are three stages of boutonniere deformity. Patients with stage 1 deformities can passively extend the PIP joint. With stage 2, the joint becomes contracted and cannot be extended fully, but the joint itself is not yet involved. Degeneration of the joint is seen in a patient with a stage 3 boutonniere deformity.
Because this patient has only a stage 1 boutonniere deformity, the most appropriate management is splinting the PIP joint in extension (ie, at 0 degrees) for a minimum of six to eight weeks. This can be performed successfully as late as six weeks after injury. Splinting of the PIP in extension helps restore central slip continuity; active DIP flexion with the PIP joint extended draws the tight, volarly displaced lateral bands into a more dorsal position while reducing DIP joint hyperextension. The distal interphalangeal (DIP) joint should be unencumbered and allowed to flex actively, and an exercise program should be initiated for joint rehabilitation.
Holding the DIP joint in extension will not correct the underlying deformity. Open central slip repair is indicated if there is an open wound, but that is not the case in this scenario. Chronic Boutonniere deformity (typically injuries older than 6-8 weeks) treatment depends on how supple the PIP joint is. In cases where full passive extension of the PIP joint is still possible, splinting for longer periods (6-12 weeks) may still result in correction. Alternatively, tendon rebalancing procedures can be performed, possibly with joint replacement if there are arthritic changes.
A 23-year-old man presents with a deep volar distal forearm laceration after striking a window. He is taken emergently to the operating room for repair of multiple flexor tendon, nerve, and arterial transections. Which of the following best describes the anatomical relationship of the flexor digitorum superficialis tendons so that the proximal and distal stumps can be correctly matched and repaired?
a. Index and middle superficialis tendons are volar to the ring and small superficialis tendons
b. Index and small superficialis tendons are volar to the middle and ring superficialis tendons
c. Index, middle, ring, and small superficialis tendons are arranged side-by-side
d. Middle and ring superficialis tendons are volar to the index and small superficialis tendons
e. Ring and small superficialis tendons are volar to the index and middle superficialis tendons
The correct response is Option D.
The superficial location of numerous, tightly packed vital structures at the volar aspect of the wrist/distal forearm makes them susceptible to injury with penetrating trauma. The patient presents with a “spaghetti wrist,” a term used to describe these devastating injuries that may result in transection of multiple flexor tendons and neurovascular structures.
A thorough knowledge of the anatomy in this region is required in order to appropriately align and repair all transected critical structures. In particular, the flexor digitorum superficialis tendons are arranged such that the middle and ring superficialis tendons are superficial to the index and small finger superficialis tendons. Of note, the flexor digitorum profundus tendons are arranged in a side-by-side fashion deep to the superficialis tendons. The median nerve is located between the superficialis and profundus musculotendinous units at this level.
The other options do not describe the correct arrangement of the superficialis tendons at the distal forearm/wrist level.
Reference(s)
- Meals CG, Chang J. Ten tips to simplify the spaghetti wrist. Plast Reconstr Surg Glob Open. 2018;6(12):e1971.
- Vaughn CJ, Raghavan SS, Hansen SL, Terry MJ. Obstacles to the care of patients with multicomponent volar wrist lacerations at a county hospital. Ann Plast Surg. 2016;76(suppl 3):S238-S240.
- Yazdanshenas H, Naeeni AF, Ashouri A, Washington ER III, Shamie AN, Azari K. Treatment and postsurgery functional outcome of spaghetti wrist. J Hand Microsurg. 2016;8(3):127-133.
