Hand - Extensor and Flexor Tendon Injury Flashcards
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 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 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 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. 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.
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.
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.
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
The correct response 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.
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
Correct answer 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.
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 75-year-old woman with severe carpal tunnel syndrome has impaired movement of the right thumb. Once the thumb is positioned correctly, it can oppose. Which of the following tendon transfers will best improve thumb motion in this patient?
(A) Abductor digiti minimi (Huber)
(B) Extensor carpi ulnaris (Phalen/Miller)
(C) Extensor indicis proprius (Burkhalter)
(D) Flexor digitorum superficialis of the ring finger (Bunnell)
(E) Palmaris longus (Camitz)
The correct response is Option E.
In this 75-year-old woman who has severe carpal tunnel syndrome, the palmaris longus tendon should be transferred to improve thumb motion. Patients with severe carpal tunnel syndrome are often unable to fully clear the thumb from the palm. The Camitz abductorplasty can be used to augment the abductor pollicis brevis tendon with the palmaris longus.
In contrast to an abductorplasty, a true opponensplasty restores thumb-finger opposition. Opponensplasties vary according to their point of insertion and associated pulleys. The Bunnell opponensplasty involves transfer of the flexor digitorum superficialis tendon of the ring finger, while the Huber opponensplasty transfers the abductor digiti minimi tendon. The Phalen-Miller opponensplasty is a transfer of the extensor carpi ulnaris tendon, and the Burkhalter opponensplasty involves transfer of the extensor indicis proprius tendon.
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 25-year-old lawyer comes to the office because of a 1-year history of limited ability to extend the right long finger at the proximal interphalangeal joint with no limitation of flexion following a jammed finger after playing basketball. X-ray study shows a normal articular surface and no evidence of fracture or foreign body. Which of the following is the most likely cause of this patient’s condition?
A) Dorsal collateral ligament contracture
B) Dorsal edema
C) Dupuytren contracture
D) Extensor adhesions
E) Flexor adhesions
The correct response is Option E.
Previous injuries to a flexor tendon or canal can result in scar formation of the tendon to an adjacent structure. Other structures which can limit digital extension include volar plate contracture (including checkrein ligaments), collateral ligament contracture (true and accessory), scarring or insufficiency of the skin volar to the joint, and joint irregularity, arthrosis, or bony block.
Dorsal collateral ligament contractures can limit the passive and active flexion of the PIP joint. Dorsal edema occurs commonly following injury near the PIP joint but also limits flexion of the joint. Dupuytren contracture rarely involves the proximal interphalangeal (PIP) joint in a patient of the age described; it is a spontaneously occurring condition that is more common with advanced age. The metacarpophalangeal joint is more likely to be involved first, followed by the PIP joint. Extensor adhesions can occur following injury to the dorsal finger and are a common cause of limitation in flexion.
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.
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 right-hand–dominant, 72-year-old man presents with clicking, locking, and pain deep to the distal palmar crease of the right ring finger. Four weeks prior he had a 40 mg triamcinolone injection with incomplete resolution of his symptoms. How long should he wait after the corticosteroid injection before performing an A1 pulley release in order to mitigate the increased risk of surgical site occurrence?
A) 1 week from injection
B) 4 weeks from injection
C) 8 weeks from injection
D) 12 weeks from injection
E) There is no increased risk of surgical site occurrence
The correct response is Option D.
The risk of surgical site occurrence is mitigated at approximately 80 days (~12 weeks) from corticosteroid injection. In a retrospective review of 999 patients who underwent corticosteroid injection for trigger digit and subsequently underwent surgery, they carefully scrutinized rates of surgical site occurrence. Charts were queried for infection/occurrence by identifying “infection,” “suture abscess,” “worrisome for infection,”, or “return to the operating room for infection.” Those who did not develop an infection had a significantly longer time between corticosteroid injection and surgery (mean 260 days vs mean 79 days, p less than 0.05). There were no differences in infection rates between those who underwent one or multiple corticosteroid injections prior to surgery (Ng et al.).1
In male patients with a single involved digit, the average success rate for corticosteroid injection alone is low (35%). One may suggest that surgery is indicated in this patient population prior to attempting corticosteroid injection. When evaluating the treatment of trigger digit from a cost perspective, males with single digit involvement or multiple digit involvement and women with multiple digit involvement should forgo corticosteroid injection because of low success rates (35%, 37%, and 56%, respectively) (Brozovich et al. and Wojahn et al).2,3
The decision to treat trigger digit with corticosteroid injection versus surgery may also be a personal decision by the patient after informed discussion with the surgeon. It is important to remember that corticosteroid injection preceding surgery may increase the risk for surgical site occurrences.
A 21-year-old man is brought to the emergency department after sustaining injuries to the right volar wrist when he punched a glass window. Surgical exploration shows a complete laceration through the palmaris longus tendon. Based on the proximity of the patient?s injury, which of the following additional structures is most likely injured?
A ) Flexor digitorum superficialis to index
B ) Flexor pollicis longus
C ) Median nerve
D ) Pronator quadratus
E ) Radial artery
The correct response is Option C.
The palmaris longus tendon is located in the middle of the volar wrist, and the median nerve is directly dorsal to this structure. In patients with palmaris longus lacerations at the level of the wrist, it is common to also find the median nerve to be injured.
The palmaris longus tendon is absent in 20% of patients. The superficial volar wrist tendons are the flexor carpi radialis, palmaris longus, and the flexor carpi ulnaris. The flexor superficialis tendons lie dorsal to the superficial flexors. However, the median nerve rests immediately dorsal to the palmaris longus at the level of the wrist. The flexor superficialis tendons are in a stacked position such that the long and ring finger flexor superficialis tendons rest volar to the index and little finger flexor digitorum superficialis tendons. The flexor digitorum profundus tendons are deep or dorsal to the flexor superficialis tendons and lie in a flat array corresponding to each finger the tendon is coursing to distally. The ulnar nerve and artery are found dorsal to the flexor carpi ulnaris. Accordingly, injuries involving the flexor carpi ulnaris tendon are frequently associated with ulnar nerve and artery injuries.
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 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.
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.
A 35-year-old man has a 10-degree extensor lag at the proximal interphalangeal joint of the right index finger three months after undergoing flexor tendon repair in zone II. On examination, active motion of the finger is as follows:
Metacarpophalangeal joint - 80 degrees
Proximal interphalangeal joint - 60 degrees
Distal interphalangeal joint - 20 degrees
What is the total active range of motion of the index finger in this patient?
(A) 130 Degrees
(B) 140 Degrees
(C) 150 Degrees
(D) 160 Degrees
(E) 170 Degrees
The correct response is Option C.
The total active range of motion of the index finger in this patient is 150 degrees. Total active motion (TAM), which is used to measure range of motion of the fingers, is the sum total of active motion of the metacarpophalangeal (MP), proximal interphalangeal (PIP), and distal interphalangeal (DIP) joints, subtracting any extension deficit of the joints. The range of motion of the MP joint (80 degrees), PIP joint (60 degrees), and DIP joint (20 degrees) is 160 degrees; the 10-degree extensor lag is then subtracted for a TAM of 150 degrees.
A person with normal TAM would have 90 degrees of motion in the MP joint, 110 degrees in the PIP joint, and 70 degrees in the DIP joint for a total of 270 degrees.
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.
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 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 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 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 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.
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 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 22-year-old man comes to the office because of injury to the right index finger flexor tendons in Zone II. During open repair, which of the following flexor tendon pulleys arise from volar plates?
A) A1, A2, and A3
B) A1, A3, and A4
C) A1, A3, and A5
D) A2 and A4
E) A4 and A5
The correct response is Option C.
The flexor tendons are bound within a fibro-osseous sheath, with pulleys essential to prevent bowstringing (and consequent poor force transfer). The pulley system includes both annual and cruciate pulleys. Pulleys A2 and A4 attach to bone. Pulleys A1, A3, and A5 are attached to the volar plates at their respective joints. The strength of pulleys, in order from strongest to weakest, are the A2, A1, and A4 pulleys. The pulleys attached to bone have a higher breaking strength compared with those attached to the volar plates.
A 42-year-old man comes to the office because he has a three-month history of significantly decreased grip strength of the dominant left hand since undergoing fusion of the proximal interphalangeal (PIP) joint of the long finger for traumatic arthritis of the joint. Fusion was performed with the PIP joint held in approximately 30 degrees of flexion. Radiographs show a well €‘healed fusion site. Physical examination shows a 25% decrease in grip strength of the left hand compared with the nondominant uninjured hand. Full active range of motion of the distal interphalangeal and metacarpophalangeal joints of the injured finger is noted. Which of the following is the most likely cause of these findings?
(A) Disuse atrophy
(B) Extrinsic tightness
(C) Flexor tendon injury
(D) Intrinsic tightness
(E) Quadriga effect
The correct response is Option E.
A quadriga (from the Latin quadria [four] and jungere [to yoke]) is a four-horse chariot that was raced in the Olympics and other sacred games. The patient described is experiencing weakness caused by the quadriga effect imposed by the fusion of the PIP joint of the long finger.
PIP fusion is often well tolerated in the index finger because that finger €™s relatively independent profundus function does not impose a significant quadriga effect on the other fingers during power grasp. PIP fusion of the long finger, however, has been shown to decrease the excursion of all profundus tendons, reducing grip strength. PIP fusion restricts profundus excursion to a greater extent than distal interphalangeal (DIP) or metacarpophalangeal (MCP) joint fusion. A significant decrease in grip strength occurs when the PIP joints of the index and small fingers are fixed at less than 45 degrees and when the long and ring fingers are fused in a position of less than 60 degrees of flexion. Any time there is limitation of profundus excursion in the long through small fingers, some decrease in grip strength is expected. By fusing the PIP joint, excursion of the profundus tendon within the finger is effectively limited.
Disuse atrophy would be unlikely in the patient described, as atrophy of the muscle bellies would have to occur in the forearm, which is far away from the site of injury. Extrinsic tightness would be noted in cases where MCP flexion limits PIP flexion. Intrinsic tightness would be noted if the patient was found to have inability to flex the PIP joint with MCP extension. Flexor tendon injury is unlikely if DIP joint and MCP joint motion are normal.
A 40-year-old man comes to the office for evaluation of sudden-onset difficulty flexing the thumb at the interphalangeal joint. He sustained a displaced scaphoid fracture 6 months ago after a bicycle collision. Which of the following tendons is most likely injured in this patient?
A ) Abductor pollicis brevis
B ) Abductor pollicis longus
C ) Adductor pollicis
D ) Flexor pollicis longus
E ) Opponens pollicis brevis
The correct response is Option D.
The flexor pollicis longus tendon courses through the vicinity of the scaphoid. Scaphoid fracture malunion or scaphoid arthritic spurs can result in ruptures to the flexor pollicis longus tendon. The other tendons described do not course in the area of the scaphoid and would not be injured with disease in the area of the scaphoid.
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 30-year-old woman comes to the office because of pain and swelling of the right radial/distal forearm. The pain worsens with ulnar deviation of the wrist over a clasped thumb. Immobilization and a corticosteroid injection have failed, and surgical release is planned. Which of the following anatomic findings is most likely to have contributed to this patient’s condition?
A) Absent extensor pollicis brevis
B) Combined first and second compartments
C) Distal muscle belly on extensor pollicis brevis tendon
D) Multiple slips of abductor pollicis longus
E) Septum between abductor pollicis longus and extensor pollicis brevis
The correct response is Option E.
There is considerable variability in the anatomy of the first dorsal compartment of the wrist; this is particularly true when considering the presence or absence of a septum in the compartment. The significance of these variations is that they may predict failure of steroid injections to resolve de Quervain disease and must be considered when releasing the compartment surgically to ensure that a complete release of all tendons is performed.
While studies vary, based on methodology of imaging, cadaveric dissection, or surgical findings, there is consistency that septa are more common in patients presenting with de Quervain disease than in the general population.
Studies have shown no association between the number of APL slips and de Quervain disease.
A 43-year-old man sustains a traumatic disruption of the central slip of the extensor tendon of the proximal interphalangeal (PIP) joint of the ring finger. If this injury is left untreated, which of the following is most likely to initiate a boutonnière deformity in this patient?
A ) Disruption of the sagittal band
B ) Disruption of the terminal extensor tendon
C ) Intrinsic tightness of the lumbricals
D ) Quadriga effect
E ) Volar subluxation of the lateral bands
The correct response is Option E.
Disruption of the central slip of the extensor tendon at its insertion into the base of the middle phalanx results in extensor lag at the PIP joint of the finger. If this deformity is left untreated, then a boutonnière deformity may result. This deformity results from subsequent volar subluxation of the lateral bands.
Disruption of the terminal extensor tendon does not result in boutonnière deformity; in fact, the use of the extensor tenotomy distal to the triangular ligament may be used for correction of chronic boutonnière deformity. Intrinsic tightness of the lumbricals and sagittal band disruption do not initiate boutonnière deformity. Quadriga effect results from an imbalance of tendon forces between adjacent fingers and is also not responsible for progression to boutonnière deformity.
Many surgeons consider the results of surgical treatment for boutonnière deformity unpredictable, and so they try splint immobilization to first regain extension and then allow the central slip to heal, even in delayed presentations. Surgical options include reattachment of the central slip and various reconstructions of the lateral bands including tenotomy, tendon grafting, and tendon transfer. Management strategies vary depending on the time since injury and the degree and ability to correct a PIP joint flexion contracture.
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 40-year-old surgeon sustains a laceration of the flexor digitorum profundus tendon of the small finger in zone II. Operative repair includes use of a six-strand core with epitendinous sutures. Which of the following is the most effective program to achieve maximum active motion of the finger?
A) Immediate free activity
B) Immediate early active flexion
C) Immediate passive flexion-active extension
D) Late passive flexion-active extension
E) Late active flexion
Correct answer is option B.
In patients with zone II flexor tendon injuries, outcome is most dependent on the repair technique and rehabilitation protocol used. Suture techniques that employ locking loops or multiple strands have been shown to be stronger and to provide a better, longer lasting repair than the standard, two-strand modified Kessler technique. Compliance is critical to successful rehabilitation. In general, an immediate, graded early active flexion program has been shown to result in greater total active motion than early passive flexion and/or late motion programs. Repair techniques that use increased strength, combined with a more detailed early, graded active flexion program, have been shown to optimize active flexion while minimizing tendon rupture. In addition, a history of smoking has been shown to correlate with poorer outcomes regardless of the method of rehabilitation
A 24-year-old woman comes for evaluation 6 days after sustaining a jamming injury to the long finger of the left hand with resultant central slip disruption and acute boutonnière injury. X-ray studies are negative for fracture or dislocation. Treatment with splint immobilization is planned. Which of the following is the most appropriate position of the finger for application of the splint?
A) Distal interphalangeal (DIP) joint extended, proximal interphalangeal (PIP) joint extended
B) DIP extended, PIP free
C) DIP flexed, PIP flexed
D) DIP flexed, PIP free
E) DIP free, PIP extended
The correct response is Option E.
The most appropriate position for splint immobilization of an injury leading to a boutonnière deformity is with the distal interphalangeal (DIP) joint free and the proximal interphalangeal (PIP) joint extended.
The patient sustained a central slip disruption of the long finger of the left hand, resulting in an acute boutonnière deformity. Patients with boutonnière deformity have flexion at the PIP joint and hyperextension at the DIP joint. There is tearing of the extensor tendon from its insertion at the base of the middle phalanx, resulting in decreased ability to extend the finger at the PIP joint. As a result, the lateral bands fall volar to the axis of rotation at the PIP joint, changing their force from extension to flexion at the PIP joint. The extensor force of the lateral bands is then directed toward the terminal tendon at the DIP joint, resulting in hyperextension of the DIP joint.
Splint immobilization of the PIP joint in extension and the DIP joint free to flex permits healing of the central slip back to the middle phalanx. Flexion of the DIP joint through movement will tend to cause the lateral bands to migrate dorsally again, reversing the effect of the boutonnière deformity. When the lateral bands move dorsal to the axis of rotation at the PIP joint, their extensor force is restored and the DIP hyperextension resolves.
Splint immobilization of both joints in extension will not encourage the dorsal migration of the lateral bands. Splint immobilization with the DIP joint in extension and the PIP joint free is recommended in zone 1 extensor tendon injuries (i.e., mallet 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 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
Correct answer 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.
A 33-year-old machinist has high median and ulnar nerve paralysis after sustaining a gunshot wound to the nondominant right elbow. Which of the following tendon transfers is most appropriate for opponensplasty in this patient?
(A) Abductor digiti quinti
(B) Extensor indicis proprius
(C) Flexor digitorum superficialis of the ring finger
(D) Flexor pollicis longus
(E) Palmaris longus
The correct response is Option B.
In order for a tendon transfer to be successful, the muscle-tendon unit must be available, of appropriate strength, and able to be spared at the donor site (ie, function of the muscle cannot be critical to the site). The strength of the antagonist muscle must also be opposed, intercalary joints should have appropriate mobility, and the excursion and direction of the muscle should be well matched. In addition, the proposed tendon transfer should demonstrate integrity and synergy.
In this 33-year-old man who has developed high median and ulnar nerve paralysis, the extensor indicis proprius is the only tendon of those listed that still has motor innervation. The patient’s injuries preclude the use of all muscle-tendon units powered by the paralyzed nerves. However, because the index finger has two independent extensor tendons, the extensor indicis proprius tendon can be used in tendon transfer.
A viable abductor digiti quinti muscle-tendon unit can be used for reconstruction in patients with thumb hypoplasia; this is known as the Huber opponensplasty. The flexor digitorum superficialis tendon of the ring finger can be used for opponensplasty when motor innervation is adequate; likewise, the function of the flexor pollicis longus tendon will most likely be restored with a transfer of the brachioradialis tendon. Transfer of the palmaris longus tendon to the abductor pollicis brevis tendon (Camitz transfer) is an abductorplasty, not an opponensplasty.
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 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 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
The correct response 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.
A 26-year-old man undergoes acute flexor pollicis longus laceration repair at the interphalangeal (IP) joint level. The proximal stump cannot be retrieved through the laceration. An incision at the distal forearm is performed. After identifying the flexor pollicis longus at this level, an attempt to retrieve the proximal stump is initially prevented by an attachment of the flexor pollicis longus to an adjacent tendon. Which of the following tendons is most likely involved in this anomalous connection?
A) Abductor pollicis longus
B) Brachioradialis
C) Flexor carpi radialis
D) Flexor digitorum profundus index
E) Flexor digitorum superficialis index
The correct response is Option D.
An anomalous connection between flexor pollicis longus (FPL) and the profundus tendon to the index finger (flexor digitorum profundus-II) was initially described by Linburg and Comstock in 1979. In their initial report, the Linburg-Comstock anomaly was detected on physical examination in one extremity in 31% of patients and in both extremities in 14%. Dissection of 43 cadavers demonstrated the anomaly in at least one extremity of 25% and in both extremities of 6%. This anomalous tendon connection has been described as a source of tenosynovitis, which is alleviated with surgical division of the connection. The connection typically occurs at the level of the distal forearm, proximal to the carpal tunnel. This connection has been blamed for failure of FPL repair due to transmission of inadvertent tension to the repair site.
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 3-year-old girl is brought by her parents for evaluation because she cannot straighten her left thumb. Her parents have observed intermittent episodes of catching or locking of the thumb since her birth. On physical examination, the thumb cannot be passively extended. A nodule is palpable over the flexor pollicis longus tendon.
Which of the following is the most appropriate management?
(A) Observation for one year
(B) Extension splinting for six months
(C) Injection of a corticosteroid into the tendon sheath
(D) Operative release of the A1 pulley
(E) Reconstruction of the extensor pollicis longus tendon
The correct response is Option D.
In this child who has a fixed flexion deformity of the thumb, most likely resulting from congenital triggering, the most appropriate management is operative release of the A1 pulley. Trigger thumb is an isolated congenital deformity that is thought to occur in 0.05% of live births; 25% to 33% of patients have bilateral findings. This condition is caused by a proliferation of synovial fluid within the tendon. Because the thumb is often minimally flexed in infants, the deformity is not typically diagnosed until age 6 months.
Studies have shown that approximately 30% of children with congenital trigger thumb will experience spontaneous resolution of the deformity by age 3 years. However, because there have been no signs of improvement of the deformity in this 3-year-old girl, simple release of the A1 pulley is indicated.
Congenital clasp thumb can produce findings similar to congenital triggering. In children with the clasp thumb deformity, there is absence of the extensor pollicis brevis and/or extensor pollicis longus tendons. This deformity is characterized by extreme flexion of the metacarpophalangeal joint and adduction of the thumb into the palm.
Conservative treatment can be ineffective in children younger than 3 years. Splinting is often impractical for compliance reasons, and injection of a corticosteroid is difficult in a 3-year-old child. Excision of a tendon nodule is recommended only to improve recurrent triggering.
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 27-year-old woman has pain and instability on radial-directed stress in the right thumb eight months after sustaining an injury to the ulnar collateral ligament. Initial management of the injury consisted of thumb spica casting for six weeks. In this patient, which of the following anatomic structures is most likely interposed between the ulnar collateral ligament and the proximal phalanx?
(A) Abductor tendon
(B) Adductor aponeurosis
(C) First dorsal interosseous muscle
(D) Flexor pollicis longus
(E) Joint capsule
The correct response is Option B.
This patient has a classic Stener lesion, in which the adductor aponeurosis becomes interposed between the ruptured ulnar collateral ligament and the base of the proximal phalanx. This lesion cannot heal spontaneously because reattachment of the ulnar collateral ligament to the proximal phalanx is blocked by the interposed tendon. It is important to identify this condition at the time of the initial injury so that operative repair can be performed without delay. Without surgical correction, the patient will have painful instability to radial stress of the metacarpophalangeal joint. The abductor tendon, the first dorsal interosseous muscle, and the flexor pollicis longus are not involved because they are not in the vicinity of the ulnar collateral ligament of the metacarpophalangeal joint of the thumb. Tearing of the joint capsule is a potential complication of a Stener lesion, and an unrepaired capsular tear can be associated with relative supination of the proximal phalanx in relation to the metacarpal. Although the joint capsule should always be inspected, and repaired if necessary, at the time of ligament repair, it is not involved with blocking of the ulnar collateral ligament. In this injury, only the adductor aponeurosis becomes interposed between the ulnar collateral ligament and the proximal phalanx.
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 25-year-old woman presents with Volkmann contracture. Examination shows the patient has supple fingers but no active flexion of the wrist or digits. MRI shows fibrosis of the volar forearm compartment. Electromyography shows no motor action potentials in the forearm flexor musculature. Which of the following is the most appropriate management of this patient to restore extrinsic finger flexion?
A) Flexor digitorum superficialis to flexor digitorum profundus tendon transfer
B) Flexor pronator slide
C) Free gracilis functioning muscle transfer
D) Pronator teres to extensor carpi radialis brevis tendon transfer
E) Z-lengthening of the flexor tendons in the forearm
The correct response is Option C.
This patient has developed Volkmann ischemic contracture, and there has been muscle fibrosis resulting from ischemia of the volar compartment. At this point, there is no functioning flexor muscle. The most appropriate management is thorough debridement of the volar forearm muscles and free functioning muscle transfer to restore extrinsic finger flexion.
Flexor digitorum superficialis to flexor digitorum profundus tendon transfer is a useful treatment to open a nonfunctional hand due to severe spasticity. Pronator teres to extensor carpi radialis brevis tendon transfer is a tendon transfer used to restore wrist extension, not flexion. Flexor pronator slide or lengthening of the flexor tendons is only indicated when there is a contracture but still some functioning muscle. Z-lengthening of the flexor tendons also relies on a mild to moderate contracture and the presence of functioning flexor muscle.
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 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 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
The correct response is Option B.
This patient has a boutonniere deformity, which results from disruption of the central slip of the extensor tendon at the PIP joint with concomitant volar migration of the lateral bands. This volar migration may not be seen until 10 to 21 days after injury. Patients with boutonniere deformities have persistent flexion of the PIP joint resulting from loss of the central slip and the unopposed forces of the flexor digitorum superficialis tendon. The transverse retinacular ligaments become stretched, and the volarly migrated lateral bands exert direct pull on the DIP joint. This leads to the characteristic findings of hypertension of the DIP joint and worsening flexion of the PIP joint.
The most appropriate management is splinting of the PIP joint in extension; this can be performed successfully as late as six weeks after initial injury. The DIP joint should be left unencumbered to allow motion, which will result in dorsal migration of the lateral bands and reestablish the normal relationship of the tendinous structures within the finger.
A 35-year-old man is brought to the emergency department after sustaining a deep laceration of his left dorsal hand. Physical examination shows a transverse 2-cm laceration over the dorsal metacarpal joint of the index finger with exposed extensor tendons. Radial nerve block at the level of the wrist is planned before exploration. The needle should be inserted superficial to which of the following landmarks?
A) Flexor carpi radialis tendon
B) Lister tubercle
C) Radial artery
D) Second dorsal extensor compartment
E) Styloid process of the radius
The correct response is Option E.
The sensory branch of the radial nerve arises between the brachioradialis and extensor carpi radialis brevis approximately 8 cm proximal to the styloid process of the radius. It pierces the fascia approximately 5 cm (3 fingerbreadths) proximal to the radial styloid. The nerve then fans out proximal to the wrist and passes superficially to the radial styloid and first dorsal compartment. The flexor carpi radialis tendon and radial artery are located in the volar forearm. The second dorsal extensor compartment and Lister tubercle of the radius are dorsal and ulnar to the radial sensory nerve.
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 56-year-old man is evaluated because of high radial nerve palsy 12 months after sustaining a gunshot wound to the upper arm with complete radial nerve transection. To restore wrist and digit extension, tendon transfers are considered. Which of the following transfers is most appropriate for this patient?
A) Brachioradialis to extensor indicis proprius
B) Flexor carpi radialis to extensor digitorum communis
C) Palmaris longus to extensor pollicis brevis
D) Pronator quadratus to extensor carpi radialis brevis
The correct response is Option B.
Tendon transfers for complete high radial nerve injuries are often performed within weeks after injury and allow restoration of wrist and digital extensor stabilization. If present, the palmaris longus tendon is transferred to the extensor pollicis longus tendon to allow for thumb extension. The flexor carpi radialis is transferred to the extensor digitorum communis for finger extension. The pronator teres is transferred to the extensor carpi radialis brevis to add support for wrist extension.
The brachioradialis is not generally a good transfer in a high radial nerve palsy as it is typically weak. The extensor indicis proprius does not usually receive a tendon for transfer as the extensor digitorum communis will provide extension to all digits, including the index. The extensor pollicis brevis does not normally receive a tendon transfer since thumb MP joint extension (in addition to IP joint extension) is normally restored with transfer to the extensor pollicis longus tendon.
Pronator quadratus is not used for tendon transfers for wrist extension and cannot reach the extensor carpi radialis brevis.
A 27-year-old man has a palpable mass on the ulnar aspect of the metacarpal head after falling on his outstretched left thumb. Physical examination shows an additional 45 degrees of laxity of the ulnar collateral ligament of the left thumb when compared with the right thumb.
Operative exploration is most likely to show interposition of which of the following structures between the ends of the collateral ligament?
(A) Abductor pollicis brevis
(B) Abductor pollicis longus
(C) Adductor pollicis
(D) Flexor pollicis brevis
(E) Opponens pollicis
The correct response is Option C.
The palpable mass on the ulnar aspect of the metacarpal head is a Stener lesion, which is formed by interposition of the fascia of the adductor pollicis between the torn ulnar collateral ligament and the metacarpophalangeal (MP) joint. The proximal stump of the ulnar collateral ligament lies superficial and proximal to the fascia of the adductor pollicis. Interposition of the adductor pollicis prevents healing of the ligament. Operative repair is indicated in patients with Stener lesions.
The abductor pollicis brevis and flexor pollicis brevis insert into the radial side of the MP joint, and the opponens pollicis inserts into the radial side of the metacarpal shaft. The abductor pollicis longus is not involved with the MP joint.
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 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 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 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 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.
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 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 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 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.
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 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.
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 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 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 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.
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 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.
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 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 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.
