Hand Fractures/Dislocations Flashcards
A 54-year-old woman is evaluated for an injury to the proximal interphalangeal (PIP) joint of the long finger of the left hand that she sustained during a motor vehicle collision. X-ray study is shown. Which of the following methods is the most appropriate surgical management of this patient’s fracture?
A) Dynamic external fixation
B) Hemihamate arthroplasty
C) Lag screw fixation
D) PIP joint arthrodesis
E) Volar plate arthroplasty
The correct response is Option A.
This patient presents with an intra-articular, or pilon, fracture of the middle phalanx base. Typically, pilon fractures are axial load injuries to the finger resulting in impaction, comminution, central depression, and splaying of the middle phalanx fracture fragments both volarly and dorsally.
Fractures involving the proximal interphalangeal (PIP) joint are generally divided into three categories: volar rim fractures, dorsal rim fractures, and pilon fractures (volar and dorsal rim) with or without joint dislocation. Joint dislocation occurs secondary to ligamentous injury and correlates to the amount of articular surface involved in the fracture. Management of these injuries depends on the fracture type, severity, degree of articular surface involvement, extent of dislocation, and associated soft-tissue injuries. Pilon fractures due to the comminution and crush component of the middle phalanx base can be very difficult to treat. Post-traumatic osteoarthritis causing stiffness, impaired function, and pain is a known complication.
Multiple different types of dynamic external fixation devices have been described in the literature. These are mostly fabricated from K-wires with or without a rubber band traction system. The devices work by the principles of a lever and ligamentotaxis to maintain fracture reduction and joint congruency and to allow early motion for joint surface remodeling. The devices are inexpensive and relatively easy to place with experience, and can be placed using local anesthesia. Dynamic distraction external fixation has been indicated for use in pilon fractures and unstable PIP joint fracture dislocations. The constructs are usually removed 4 to 6 weeks after fracture consolidation and clinical healing is present. Most studies report 60 to 88 degrees of PIP motion with good patient satisfaction and return of function. The presence of arthritic changes on x-ray studies is common after these injuries. Pin tract infections up to 40% have been reported in retrospective studies; however, these seem to be treated with oral antibiotics alone and do not require pin removal. They do not progress to osteomyelitis.
PIP joint arthrodesis is an option for treatment in very severe pilon fractures or crush injuries with severe soft-tissue involvement; however, this sacrifices motion and should be reserved for cases where there are no other viable treatment options.
Hemi-hamate arthroplasty and volar plate arthroplasty are operations described to treat PIP joint fracture dislocations with isolated volar rim involvement. These procedures require an intact dorsal cortex of the middle phalanx base to achieve stable fixation. Both procedures are indicated for comminuted fractures involving 30 to 50% of the articular surface of the middle phalanx base.
Open reduction and internal fixation of pilon fracture with locking plates has been described, but is technically challenging and requires significant soft-tissue dissection compared with percutaneous dynamic external fixation. Lag screws are inadequate fixation in general for pilon fractures. Isolated volar rim fractures with a larger fracture fragment can be treated successfully with lag screws.
A 20-year-old rugby player is evaluated for an acute thumb injury 4 hours after falling onto his outstretched hand while being tackled. X-ray study is shown. Surgical intervention is planned. Which of the following is the most appropriate force to apply to the thumb metacarpal during reduction?
A) Abduction
B) Axial compression
C) Flexion
D) Supination
The correct response is Option A.
In a Bennett fracture, the smaller volar-ulnar fragment is retained by the anterior oblique (beak) ligament, while the abductor pollicis longus, thumb extensor tendons, and the adductor pollicis combine to distract the base of the larger shaft fragment radially, dorsally, and proximally. These distracting forces create joint incongruity, which is a relative indication for fracture reduction. These forces must be countered to reduce the fracture, thus, requiring axial distraction, pronation, and abduction of the metacarpal shaft, while simultaneously applying external pressure at the radial base of the metacarpal.
Axial compression will worsen proximal migration of the metacarpal shaft. Extension will worsen dorsal displacement, and supination will further distract the volar surfaces of the fracture fragments. Application of these forces will not promote fracture reduction.
2018
A 30-year-old man is evaluated for a hand injury after punching a wall. X-ray study shows a fracture of the fifth metacarpal neck. Which of the following findings is most likely to require surgical intervention?
A) Angulation
B) Callus formation
C) Impaction
D) Malrotation
E) Shortening
The correct response is Option D.
Malrotation causes scissoring of the affected digit, which will adversely affect neighboring digits. This will affect activities of daily living and is an indication for operative intervention. Other indications for operative intervention include displaced intra-articular fractures, severe soft-tissue injury, unstable open fractures, segmental bone loss, and multiple fractures. Angulation is usually dorsal tip–oriented because of intrinsic and extrinsic muscle pull. A good rule of thumb is the 10, 20, 30, 40 for digits two, three, four, and five. The fourth and fifth digits have carpometacarpal joint mobility and can tolerate larger angulation. The fifth digit metacarpal may even tolerate up to 70 degrees of angulation as long as there is no extensor lag. Impaction can lead to shortening and/or angulation, which is tolerated more than rotational deformities. Similarly, shortening is well tolerated as long as there is no extensor lag. Nonoperative complications include aesthetic with loss of knuckle and possible pain in the palm from the metacarpal head. Callus formation is indicative of an old, healed fracture.
2018
A 25-year-old man comes to the office 48 hours after “jamming” the right index finger while playing volleyball. The patient reports pain and swelling around the proximal interphalangeal (PIP) joint that prevents him from flexing the digit. Examination does not show malrotation or angulation of the fingertip, but range of motion is limited at the PIP joint because of pain. X-ray studies are shown. Which of the following is the most appropriate next step in management?
A) Arthrodesis of the PIP joint
B) Dorsal block splinting
C) Dynamic traction reduction
D) Hemi-hamate arthroplasty
E) Splint immobilization for 4 weeks
The correct response is Option C.
Dislocations of the proximal interphalangeal joint may be treated with splinting, typically dorsal block splinting, and early motion. In the setting of a volar dislocation, where injury to the central slip is suspected, splinting for 3 to 6 weeks in extension may be necessary. Splinting alone is inadequate treatment for fracture dislocations where the middle phalanx remains subluxed dorsally compared with the proximal phalanx condyles. This particular injury requires reduction prior to splinting or other methods of maintaining the joint congruity. Fracture/dislocations of the proximal interphalangeal joint that can be reduced and maintained with joint flexion can be successfully treated with either dorsal block splinting or percutaneous pinning as a dorsal block. Injury patterns amenable to this treatment typically involve <40% of the volar articular surface. The lateral radiograph demonstrates a comminuted fracture of 50 to 60% of the volar articular surface of the middle phalanx with the presence of a centrally depressed fragment; which is too large for a hemihamate graft. The AP radiograph shows comminution extending obliquely as well as in the sagittal plane, suggesting a pilon-type injury. This pattern of injury would not be reduced adequately with dorsal blocking alone. Complex fractures/dislocations of the base of the middle phalanx prove challenging to treat. Keys to success involve reduction of the dorsally dislocated middle phalanx base, restoration of articular congruity, and provision of early motion.
One useful approach to these injuries involves application of a dynamic traction device. Commercial devices are available; however, a construct composed of pins and rubber bands, described by Suzuki, allows creation of a dynamic traction device with materials available at any hospital. Outcomes from this treatment can achieve anywhere between 70 to 90% of the motion of the uninjured joint. When unstable, simple fracture/dislocations of the proximal interphalangeal joint can be treated with open reduction and internal fixation. Multiple techniques have been employed including dorsal, palmar, and midlateral approaches. Screws, cerclage wires, and even miniplates have been used. The lateral radiograph demonstrates this with the depressed articular fragment in the volar half of the joint surface. When severe comminution destroys enough of the volar half of the middle phalanx base so as to make restoration of stability unlikely, an osteochondral graft from the dorsum of the hamate between the little and ring finger metacarpal bases can be harvested and used to replace the lost articular surface. Use of this procedure requires the presence of a dorsal articular segment with some stability, to which the graft may be affixed. The AP radiograph demonstrates fracture lines extending through the dorsoradial articular surface of the middle phalanx, making hemi-hamate grafting difficult if not impossible. Arthrodesis is reserved as a salvage repair after attempts at primary repair have failed.
2017
Which of the following is most likely an open fracture?
A) Barton
B) Colles
C) Epiphyseal
D) Salter-Harris III
E) Seymour
The correct response is Option E.
The Seymour fracture in children displaces through the epiphysis with the nail matrix interposed between the fragments. It is always an open fracture.
The Salter-Harris classification is the most commonly used method to describe the five most frequent patterns of pediatric fractures involving the physis. The classification helps explain the mechanism of injury and anticipate the consequences of the fracture upon subsequent growth. A Salter-Harris III fracture is epiphyseal but is not necessarily open.
Colles and Barton fractures are seen in the distal radius.
2017
A 28-year-old man is brought to the emergency room because of pain, swelling, and deformity of the right small finger and a laceration over the finger after being involved in a motor vehicle collision. Physical examination shows a 7-mm laceration over the fifth metacarpal shaft. X-ray studies confirm a significantly displaced transverse metacarpal shaft fracture of the right small finger. Which of the following is the most appropriate management?
A) Closed reduction of the fracture and splint immobilization followed by 7 to 10 days of outpatient oral antibiotic therapy
B) Closed reduction of the fracture followed by splint immobilization only
C) Emergent debridement in the operating room followed by external fixation of the fracture
D) Inpatient intravenous antibiotic therapy and debridement in the operating room within 48 hours
E) Irrigation of the wound in the emergency room, splint immobilization, 24 hours of oral antibiotic therapy, and elective operative fixation of the fracture
The correct response is Option E.
This patient has a displaced Grade I open fracture of the fifth metacarpal shaft. Appropriate management includes irrigation and debridement of the wound in the emergency room, splint immobilization, and a brief course of antibiotic therapy. This allows the fracture to be managed as if it were a closed injury. Transverse shaft fractures typically are unstable and require some type of elective fixation beyond splint immobilization.
Open fractures usually are classified according to the Gustilo-Anderson scale, although outcomes of upper extremity open fractures do not necessarily correlate to this system. Grade I injuries are defined as fractures with open wounds <1 cm. Grade II fractures have open wounds measuring between 1 and 10 cm. Grade IIIA fractures have wounds >10 cm with comminution but adequate soft-tissue coverage. Grade IIIB fractures have wounds >10 cm with extensive periosteal stripping that requires soft-tissue reconstruction. Grade IIIC fractures have large wounds with associated vascular injury.
In upper extremity fractures, studies have not correlated time to operative debridement or the administration of antibiotic therapy with ultimate outcomes in terms of infection, malunion, or osteomyelitis. Factors that have been shown to correlate to poor outcomes in large-scale studies have been high injury severity score, Gustilo grade III, and fractures of the tibia/fibula. Shorter duration of antibiotic administration for open fractures has not been shown to result in a higher rate of infection. The current recommendation from the American Society of Orthopedic surgeons is a 3-day regimen of antibiotics for Grade I/II injuries and 5 days for Grade III.
Grade I injuries have only a minor soft-tissue component and there is no role for emergent surgery, hospital admission, or the need for provisional external fixation.
Closed reduction and splint immobilization are not appropriate for unstable fractures as definitive management in a healthy, young patient. In addition, there is no role for prolonged courses of antibiotic therapy. The fracture can be treated with percutaneous pin fixation or plate fixation depending on the preference of the surgeon.
2016
The metacarpophalangeal (MCP) joint of the thumb is which of the following types of joint?
A) Ball-and-socket
B) Condyloid
C) Hinge
D) Pivot
E) Saddle
The correct response is Option C.
The metacarpophalangeal (MCP) joint of the thumb and interphalangeal joints of the index through little fingers are hinged joints and allow flexion and extension only. Lateral forces can disrupt the collateral ligaments, resulting in partial or full tears.
Condyloid joints allow flexion and extension, abduction and adduction, and circumduction, and they can be seen in the MCP joints of the index through little fingers and in wrist joints. Saddle joints allow flexion and extension, abduction and adduction, and circumduction, and they can be seen in the carpometacarpal joint on the thumb. Ball-and-socket joints allow flexion and extension, abduction and adduction, and internal and external rotation, and they can be seen in the shoulder and hip joints. Pivot joints allow rotation and are seen in the atlas and axis bones.
2015
A 24-year-old man is evaluated because of a 1-cm metacarpal defect after sustaining a gunshot wound to the hand. In addition to operative fixation of the fracture, which of the following materials placed into the defect is most likely to promote osteogenesis?
A) Calcium hydroxyapatite
B) Cancellous autograft
C) Cortical allograft
D) Demineralized bone matrix
E) Methylmethacrylate
The correct response is Option B.
The material that will most likely provide osteogenesis is cancellous autograft.
Bony defects can be constructed by a variety of methods, and there has been an increase in the number of biomaterials that can be used. Autograft bone is obtained from the same individual, while allograft bone is obtained from another human source (i.e., cadaveric or donor). Demineralized bone matrix does not contain calcium, but retains growth factors and proteins as the nonmineralized components of bone. Calcium hydroxyapatite is a bone substitute that mimics bone in mineral structure, and gradually becomes replaced with native bone. Methylmethacrylate is used in orthopedic bone cement, and is not biodegraded or replaced, but can provide rapid structural support.
Osteoconduction refers to the replacement of the graft material through a process known as creeping substitution, where native cells from the surrounding bone break down the material and replace it with new bone. This is the primary mechanism of healing of cortical bone grafts. It is also seen in biocompatible materials that are replaced with bone, such as calcium hydroxyapatite.
Osteoinduction refers to the stimulation of bone-forming cells from surrounding host tissues, resulting in activation of progenitor cells and differentiation into osteoblasts, leading to the creation of new bone. This process occurs due to growth factors that are present in the graft material, and can be seen in cancellous bone grafts, as well as demineralized bone matrix, which contains growth factors. Osteoinduction also occurs with cortical grafts, although to a lesser extent.
Osteogenesis refers to new bone formation, which is provided from surviving cells within the graft material. In order for osteogenesis to occur, viable cells must be transferred with the graft. This is seen in autograft materials, but not in allograft materials, which are processed and may be decellularized. Cells contained within autografts can survive and produce new bone. Vascularized bone transfer may give rise to more cell viability than traditional autografts, because it maintains perfusion to the grafted bone, rather than relying on nutrients from the bed.
2015
An 11-year-old boy is brought to the emergency department after sustaining an injury to the tip of the left long finger while playing baseball. The long fingertip is held in a flexed position. The proximal nail plate is slightly visible superficial to the eponychial fold, and a small subungual hematoma is noted. An x-ray study is shown. Which of the following is the most appropriate management?
A) Closed reduction and distal interphalangeal joint extension splinting for 6 to 8 weeks
B) Closed reduction, removal of nail plate, and percutaneous pinning
C) Open reduction, repair of nail bed, and Kirschner wire fixation
D) Repair of zone I flexor tendon avulsion
E) Suture repair of lacerations and observation for 6 weeks
The correct response is Option C.
This patient has a Seymour fracture, or an open physeal/juxta-epiphyseal fracture of the distal phalanx. These injuries present as mallet-like injuries, but they are open fractures by definition. The treatment of choice is open reduction, debridement of the fracture site, repair of associated nail bed laceration, and Kirschner wire fixation of the fracture across the distal interphalangeal (DIP) joint. The injury is secondary to hyperflexion and is essentially a Salter I or Salter II fracture of the distal phalanx. The flexed posture occurs because the terminal extensor tendon inserts on the proximal dorsal epiphysis, while the flexor digitorum profundus inserts on the metaphysis of the bone distal to the fracture site. These injuries can often be mistaken for mallet injuries or DIP dislocations. Often a flap of nail bed matrix becomes interposed between the fracture fragments, preventing closed reduction. This must be repaired. It is recommended to not discard the nail plate, because it helps maintain bone reduction. Dorsal physeal widening and flexion of the distal fracture fragment is seen on lateral x-ray studies.
Observation alone for a Seymour fracture, mallet finger, or DIP dislocation is inappropriate.
Closed reduction and DIP extension splinting is generally the treatment of choice for mallet-type injuries. These can be purely soft-tissue mallet fingers or osseous mallet fractures. Initial treatment should include closed reduction by extension or hyperextension and splinting that isolates the DIP joint in extension. Generally, the splint is worn for 6 to 8 weeks continuously, and then for a period of time at night as indicated. Compliance may be an issue with the pediatric or adolescent population, and the patient should be seen regularly to assess splint fit and skin integrity.
Closed reduction and pinning may be necessary for osseous mallet fingers with associated volar subluxation of the distal phalanx. Several techniques have been described, but this is not appropriate for a Seymour fracture. The nail bed tissue must be reduced from the fracture site to achieve anatomic reduction in this case. Also, closed treatment has an unacceptable incidence of infection, residual finger deformity from incomplete reduction, and nail deformity.
A zone I flexor tendon avulsion, or jersey finger, would present with the DIP joint held in extension. This is opposite to the presentation of this patient. In that case, the patient would require open exploration and reinsertion of the profundus tendon to the distal phalanx via bone tunnels or suture anchor.
2015
A 5-year-old boy who underwent closed reduction and pinning of a supracondylar humerus fracture is evaluated in the postanesthesia care unit because of absence of palpable radial pulse in the left wrist. Physical examination shows the left hand is warm with color similar to the right hand. No pulses are palpable at the level of the wrist. Without surgical exploration, which of the following is the most likely outcome for the left forearm?
A) Fibrosis of the deep flexor compartment
B) Ischemic necrosis of the radial hand
C) Median nerve palsy
D) Physeal arrest in the forearm bones
E) No functional impairment
The correct response is Option E.
Vascular impairment related to pediatric supracondylar fractures occurs in roughly 5 to 10% of patients. Given the nontrivial morbidity of exploration of the brachial artery after reduction of the supracondylar fracture, controversy exists over what criteria should prompt surgical intervention. Recent large, retrospective studies have demonstrated that absence of pulses in the wrist after reduction is not, by itself, associated with poor outcomes. Most patients who lack pulses immediately after reduction, but who have an otherwise perfused hand, go on to recover a palpable radial pulse within 24 to 48 hours after the reduction. In this patient with a perfused hand, observation can be expected to result in a good outcome.
Physeal arrest can occur secondary to ischemia, but this would not be the expected outcome based on the perfusion of the hand. Fibrosis of the deep flexor compartment (Volkmann ischemic contracture) is associated with compartment syndromes but would be rare in this setting. Median nerve impairment associated with the vascular insufficiency at the time of injury is advocated as an indication for surgical exploration. Development of a new median palsy as a late result of the vascular injury is unlikely.
Rare case reports of late development of ischemia in the forearm and hand occur, and families should be counseled to watch for color or temperature changes in the hand following discharge after the recommended observation period of 24 to 48 hours.
2015
A 29-year-old man comes to the office because of pain and the inability to flex the little finger of his dominant right hand 6 weeks after injuring it during a recreational football game. He reports that he “jammed” the finger and then pulled it back into place. He did not seek medical care at the time of the injury. He is concerned about maintaining an active lifestyle and preserving the maximum range of motion. Physical examination shows the inability to flex at the proximal interphalangeal joint. Lateral x-ray study of the finger is shown. Which of the following is the most appropriate management?
A) Arthrodesis
B) Dynamic external fixation
C) Hemi-hamate arthroplasty
D) Open reduction and internal fixation
E) Silicone implant reconstruction
The correct response is Option C.
Proximal interphalangeal (PIP) joint fracture dislocations are common finger injuries that result in pain and loss of motion. Normal PIP joint range is 0 to 110 degrees.
This type of injury normally results from an axial load applied to the finger in a hyperextended position. If more than 30 to 50% of the volar base of the middle phalanx breaks off, the joint will become unstable.
If identified early, the fracture can be managed with either open reduction and internal fixation or dynamic external fixation. At 6 weeks post injury, the fracture fragments would not be mobile, making dynamic external fixation unsuccessful. In addition, it is normally not possible to mobilize the fracture fragments in a manner that they can be reduced and fixated this far out from injury.
Silicone implant arthroplasty can provide pain relief and preserve limited PIP motion in low-demand patients such as those with rheumatoid or osteoarthritis. It would not be sufficiently durable to tolerate the lifestyle of this patient and does not provide as much range of motion as a hemi-hamate graft.
Arthrodesis will provide durable stability and pain relief even in a young patient. However, it sacrifices all motion at the PIP joint. As such, it should be reserved as a salvage option if motion-preserving options fail.
Since its description by Hastings in 1999, hemi-hamate arthroplasty has become a reconstruction of choice for unstable late dorsal fracture-dislocations, particularly those involving more than 50% of the articular surface. The dorsal central portion of the hamate is harvested as an osteocartilaginous graft. Due to the thicker articular cartilage of the distal hamate compared with the base of the middle phalanx, the bone surfaces may appear uneven even though the cartilage surface (and, therefore, the joint surface) is confluent.
2014
A 17-year-old boy comes to the office because of ongoing pain of the right hand after he punched a wall 5 days ago. Physical examination demonstrates tenderness of the fifth carpometacarpal joint. Posteroanterior, oblique, and lateral x-ray studies taken at an urgent care facility were read as negative by the radiologist. Which of the following additional radiographic views is most likely to help confirm this patient’s diagnosis?
A) Anteroposterior with 30 degrees of pronation from full supination
B) Carpal tunnel view with wrist in full extension
C) Clenched fist lateral in neutral forearm position
D) Lateral with 15 degrees of supination from neutral forearm position
E) Posteroanterior with 45 degrees of supination from full pronation
The correct response is Option A.
Injuries to the fifth carpometacarpal joint, including subluxation, dislocation, and fracture-dislocation, are often missed with standard two-view and three-view hand images. Two views have been suggested to help detect this subtle injury:
Anteroposterior view with forearm pronated 30 degrees from full supination. This view shows more clearly the profile of the articulation between the hamate and fifth metacarpal base. (This is similar to the “reverse oblique” view, which is typically done in 45 degrees of pronation and might also be useful.)
Lateral with 30 degrees of pronation. This view is especially helpful for detecting subluxation of the metacarpal dorsally off of the hamate. In some cases, CT scan may be warranted if plain films are inconclusive.
2019
An 11-year-old boy is brought to the office with an acute injury of the left small finger. A lateral x-ray study is shown. Which of the following is the most appropriate description of this patient’s injury?
A) Displaced Salter Harris fracture of the middle phalanx
B) Displaced Salter Harris fracture of the proximal phalanx
C) Nondisplaced Salter Harris fracture of the distal phalanx
D) Nondisplaced Salter Harris fracture of the middle phalanx
E) Nondisplaced Salter Harris fracture of the proximal phalanx
The correct response is Option A.
This is a displaced growth plate fracture of the small finger middle phalanx. There is a 90% displacement of the metaphysis relative to epiphysis. Although there is no obvious involvement of the metaphysis and, thus, the injury could be interpreted as a Salter Harris I fracture, minor concurrent involvement of some portion of the metaphysis (making it technically a Salter Harris II fracture) cannot be excluded and is quite common. The proximal and distal phalanges of the small finger are not injured.
The mnemonic “SALTER” may be used to recall Salter–Harris fracture types:
Type I: S (Slipped). The fracture occurs through the cartilage of the growth plate (physis) with an incidence of 5-7%.
Type II: A (Above). The fracture occurs above the physis, through the metaphysis. This is the most common type, occurring in 75% of patients.
Type III: L (Lower). The fracture occurs below the physis into the epiphysis. This occurs in 7-10%.
Type IV: TE (Through Everything). The fracture occurs through everything which includes the metaphysis, physis, and epiphysis. This type occurs in 10%.
Type V: R (Rammed or crushed). The growth plate (physis) has been crushed. This occurs in <1%.
2019
A 6-year-old boy presents with a supracondylar fracture sustained during a fall on an outstretched hand. A splint with the elbow flexed less than 90 degrees is placed. The patient is screaming in pain. Examination shows the affected hand has a 3-second capillary refill. Which of the following is the most appropriate next step in management?
A) Closed reduction
B) Continued observation and application of ice packs
C) Elevation of the arm
D) Exploration of the brachial artery
E) Replacement of the current splint with an elbow extension splint
The correct response is Option A.
Supracondylar fractures are one of the most common traumatic fractures seen in children. It occurs most commonly in children 5 to 7 years of age with similar male and female incidence. The mechanism is usually from a fall onto an outstretched hand. The fracture can lead to severe forearm edema, then ischemia leading to Volkmann’s contracture.
Immobilization would be long arm casting with the elbow flexed at less than 90 degrees. Arm elevation would decrease tissue perfusion and would therefore be contraindicated. Immediate bedside closed reduction by gentle traction and elbow flexion to 20 to 40 degrees would be indicated in this case as a next step. If the closed reduction is unsuccessful or ischemia persists after reduction or recurs, urgent operative closed reduction with percutaneous pinning is required. Pins are placed to prevent recurrence. Brachial artery exploration could be required if ischemia has not resolved even after successful reduction, but not initially.
2020
A 26-year-old man sustained a crush injury to the tip of the left middle finger with an associated fracture at the dorsal base of the distal phalanx with nail bed injury 6 months ago. No treatment was provided. Examination shows non-union of the distal phalanx. Which of the following is the most likely secondary deformity in this patient?
A) Boutonniere deformity
B) Jersey finger
C) Quadriga
D) Swan neck deformity
E) Trigger finger
The correct response is Option D.
The scenario described involves a bony mallet deformity in which a distal phalanx fracture is associated with disruption of terminal extension at the distal interphalangeal joint. If untreated, the DIP extension loss due to a non-union of a bony mallet injury may progress to a swan neck deformity through compensatory proximal phalangeal hyperextension in the setting of continued and persistent flexion at the distal interphalangeal joint (from unopposed pull of the flexor digitorum profundus tendon). A secondary swan neck deformity may occur because of dorsal subluxation of the lateral bands and attenuation of the volar plate and transverse retinacular ligament at the PIP joint level.
A jersey finger is caused by rupture of the terminal flexor digitorum profundus. A boutonniere deformity can be caused by an injury to the central slip (but not the terminal extensor tendon). Quadriga is due to loss of length of a repaired FDP tendon, causing the finger with the repaired tendon to reach terminal flexion sooner than the other fingers whose FDP tendons are of normal length. A trigger finger does not involve a fracture of the DIP joint.
2020
A healthy 11-year-old boy is brought to the emergency department because of worsening redness and pain around the site of an injury to the middle finger of the left hand. The patient sustained the original injury 3 weeks ago while wrestling with his brother. The patient had swelling and pain of the finger, but the pain resolved quickly, so no medical care was sought. The patient’s mother reports that she noticed a small bump on the dorsum of the finger since then. However, the patient developed redness and pain 2 days ago at the same site, both of which have worsened. An image and x-ray studies are shown. Which of the following is the most likely cause of this patient’s symptoms?
A) Biting of nails
B) Exposure to Pasteurella species
C) Flexor tendon avulsion
D) Immunocompromised state
E) Trapped germinal matrix
The correct response is Option E.
This patient has a Seymour fracture—a juxta-epiphyseal open fracture—of the distal phalanx as evidenced by the eponychial disruption and fracture pattern on x-ray study. These are open fractures traditionally frequently with associated nail bed transection. Unfortunately, secondary to delay in treatment, the patient developed osteomyelitis.
These patients often present with a mallet-appearing deformity from flexion of the distal fracture segment, the nail may be disrupted (with the distal nail bed) and lay superficial to the eponychial fold, while the transected nail bed proximally (germinal matrix) becomes entrapped within the fracture, making closed reduction prone to failure. Acute treatment in the emergency department or operating room consists of nail plate removal, reduction of the trapped nail bed, irrigation and debridement of the fracture site, reduction of the fracture, nail bed repair, nail plate replacement, and immobilization. Instability or inadequate reduction warrants operative intervention and may require Kirschner wire fixation. Inadequate reduction and/or delayed treatment are critical influences of infection rates. In a study by Reyes and Ho in the Journal of Pediatric Orthopaedics, investigators reviewed acute appropriate reduction, acute partial treatment, and delayed treatment. No infections occurred in the acute appropriately managed group, whereas 15% of the patients developed infections in the partially treated group, and 45% of the delayed treatment group developed infections. Biting of nails has been associated with nontraumatic paronychial infections. There is no history of immunocompromised state, and healthy children can acquire infections with these injuries. This patient sustained the injury wrestling his brother as opposed to from an animal bite. Pasteurella is not the most frequent bacteria associated with infections in patients who have sustained Seymour fractures. Flexor tendon avulsions, also known as jersey fingers, are traditionally closed and would demonstrate lack of flexion of the distal interphalangeal joint.
2020
A 7-year-old boy who is a soccer goalie is brought to the emergency department because of right hand pain after being struck in the hand by the ball at practice. An x-ray study is shown. Attempts at reduction are unsuccessful. If this patient undergoes surgical intervention using a volar approach, which of the following structures has the greatest iatrogenic risk for injury?
A) Collateral ligament
B) Digital nerve
C) Flexor digitorum profundus tendon
D) Lumbrical muscle
E) Volar plate
The correct response is Option B.
This patient has a dorsal metacarpophalangeal joint dislocation of the right index finger. These dislocations are commonly complex and unable to be reduced nonoperatively. Surgical intervention has been described from both the dorsal and volar approaches.
The volar approach seems intuitive, since the metacarpal head is easily palpable in the palm and immediately accessible. On opening the skin, however, the radial digital nerve is quite often draped or tented across the metacarpal head and is at significant risk for injury during the initial exposure of the joint dislocation. Photographs are shown. After assuring the nerve is safe, the task of extricating the volar plate from behind the metacarpal head is often a daunting task, and one must take care to protect both the nerves as well as the vulnerable cartilage surface of the metacarpal head during this maneuver.
The dorsal approach avoids the increased risk for nerve injury, and some feel that the reduction is easier and that the surgery is therefore faster. After identifying the volar plate, this structure can simply be divided down its midline, allowing the split volar plate to fall to either side of the reducing metacarpal head as it relocates into position. Although the volar plate is then inaccessible for repair, this step is not felt to be required, since stability of these injuries is usually restored following reduction with very low risk for redislocation or long-term instability in the fingers.
The volar plate and collateral ligaments are often injured in dorsal dislocations and, as such, are not at risk in the surgical approach. The lumbrical muscle and flexor digitorum profundus tendon are adjacent to volar aspect of the metacarpal proximal phalanx, but they are not distorted by the dislocation to the degree of the radial digital nerve, putting them at less risk for inadvertent injury.
2023
