Hand Fractures and Dislocations Flashcards
A 22-year-old man comes to the emergency department after falling onto his outstretched left hand. An x-ray study and a clinical photograph are shown, demonstrating dorsal metocarpophalangeal joint dislocation. Attempted reduction isunsuccessful. Reduction is most likely blocked by which of the following anatomical structures?
A) Central slip
B) Dorsal capsule and collateral ligaments
C) Flexor tendons and intrinsic muscles
D) Lateral bands
E) Sagittal bands
C) Flexor tendons and intrinsic muscles
How do dorsal metocarpophalangeal joint dislocations occur?
They occur with forced hyperextension injuries.
Most common fingers for dorsal metocarpophalangeal joint dislocations?
Index finger, followed by the little finger
What ruptures after a complete dorsal metocarpophalangeal joint dislocation?
With complete dislocation, the volar plate ruptures in the membranous proximal portion and becomes interposed in the joint. If this were the only structure blocking reduction, traction on the joint would be sufficient to draw the proximal edge of the volar plate over the metacarpophalangeal head.
Why would a metocarpophalangeal joint dislocation be irreducible?
Additional taut medial and lateral structures are drawn around the narrow metacarpophalangeal neck:
Index finger: lumbrical on the radial side and the flexor tendons on the ulnar side
Little finger: common tendon of the abductor digiti minimi and flexor digiti minimi on the ulnar side and the lumbrical and flexor tendons on the radial side
A 30-year-old woman comes to the office because she is unable to flex the distal interphalangeal (DIP) joint of the right long finger. An x-ray study is shown (avulsed bone fragments on volar aspect of proximal DP). She reports that she injured the finger 2 days ago when attempting to restrain her dog. Physical examination shows no active flexion of the DIP joint; however, the DIP joint can be passively flexed from 0 to 80 degrees. During surgical exploration, the distal end of the flexor digitorum profundus tendon is most likely to be found at the level of which of the following structures? A ) A4 pulley B ) Camper chiasm C ) Central slip D ) Sagittal band E ) Terminal tendon
A ) A4 pulley
The injury to the patient describedis commonly referred to as a jersey finger:
Injury may involve a pure soft-tissue rupture of the flexor digitorum profundus (FDP) tendon, or a portion of the volar proximal aspect of the distal phalanx may be avulsed along with the tendon. Injuries are classified based on the type of fracture and how proximally the FDP tendon has retracted. In the patient described, a large fragment of the distal phalanx base remained attached to the FDP tendon. The tendon and fragment are held in this position by the A4 pulley.
What holds the tendon and bone fragment in place in an avulsion of FDP from the thumb DP?
A4 pulley
Camper chiasm
Camper chiasm is where the flexor digitorum superficialis (FDS) tendon splits to pass dorsal to the FDP tendon en route to its insertion at the base of the middle phalanx.
How are ‘jersey finger’ injuries classified?
Injury may involve a pure soft-tissue rupture of the flexor digitorum profundus (FDP) tendon, or a portion of the volar proximal aspect of the distal phalanx may be avulsed along with the tendon. Injuries are classified based on the type of fracture and how proximally the FDP tendon has retracted.
Sagittal band (hand)
The sagittal band is a stabilizer of the extrinsic extensor tendons over the dorsum of the metacarpophalangeal (MCP) joint.
A 25-year-old man comes to the emergency department six hours after sustaining an acute dorsal dislocation of the proximal interphalangeal joint of the ring finger of the dominant right hand. Following reduction, the joint is stable when flexed approximately 30 degrees but is unstable in full extension. Postreduction lateral radiographs show that approximately 20% of the volar articular surface is avulsed from the base of the middle phalanx. Which of the following is the most appropriate initial management?
A ) Extension-block splinting
B ) Hemi-hamate arthroplasty
C ) Repair of the torn collateral ligaments
D ) Screw fixation of the fracture fragment
E ) Volar plate arthroplasty
A ) Extension-block splinting
Generally, if only 20% of the volar articular surface is avulsed from the base of the middle phalanx, when the fracture is reduced, there is sufficient collateral ligament attached to both the volar lip fragment and the majority of the middle phalanx to bring the fragments into close apposition. Extension-block splinting can safely be performed up to a 30-degree angle block.
Treatment of acute dorsal dislocation of the PIP depends on:
Percentage of articular surface disruption and the presence of impaction
Management when <20% of the volar articular surface is avulsed from the base of the middle phalanx in dorsal PIP dislocation
Generally, if only 20% of the volar articular surface is avulsed from the base of the middle phalanx, when the fracture is reduced, there is sufficient collateral ligament attached to both the volar lip fragment and the majority of the middle phalanx to bring the fragments into close apposition.
Extension-block splinting can safely be performed up to a 30-degree angle block.
Management when >20% of the volar articular surface is avulsed from the base of the middle phalanx in dorsal PIP dislocation
If more flexion is required to reduce the fragments or maintain stability, then closed reduction and splinting is probably not adequate because unacceptable flexion contracture may result. In such cases, the wound may be opened and screw fixation of the fracture fragment may be indicated.
Management of dorsal PIP dislocation with comminution, impaction, or greater amounts of articular loss
In cases of comminution, impaction, or greater amounts of articular loss, a volar plate arthroplasty or hemi-hamate arthroplasty may be indicated. Other dynamic splinting methods of treating these injuries in certain cases are the Agee force-couple technique and the Schenck splint technique.
Why not closed reduction/splinting for >20% avulsion of the volar articular surface from the base of the middle phalanx, in dorsal PIP dislocation?
If more flexion is required to reduce the fragments or maintain stability, then closed reduction and splinting is probably not adequate because unacceptable flexion contracture may result. I
Maximum cases of dorsal PIP that can be close reduced
The maximum percentage of middle phalanx joint avulsion that is acceptable for closed reduction is approximately 30% to 40% and no more than 30 degrees of flexion can be accepted to maintain reduction.
A 30-year-old woman who is a professional athlete comes to the office one week after sustaining an injury to the thumb of the dominant right hand. Physical examination and radiographs confirm a displaced Bennett fracture. Closed reduction of the fracture followed by percutaneous pin fixation is planned. In addition to longitudinal traction on the thumb while exerting pressure over the dorsoradial aspect of the metacarpal base, which of the following is the most appropriate reduction maneuver?
(A)Palmar abduction and pronation of the thumb
(B)Palmar adduction and pronation of the thumb
(C)Palmar abduction and supination of the thumb
(D)Palmar adduction and supination of the thumb
(A)Palmar abduction and pronation of the thumb
Mechanism of injury in a Bennett fracture
The mechanism of injury is an axially directed force through the partially flexed metacarpal shaft.
Mechanism of injury in a Rolando fracture
The mechanism of injury is an axially directed force through the partially flexed metacarpal shaft.
Bennett fracture
Bennett fracture is a two-part fracture with a volar lip fragment ofvariable size and the remaining metacarpal base, which subluxates radially, proximally, and dorsally.
In a Bennett fracture, there is an avulsion of the main substance of the thumb metacarpal from the volar ulnar portion of the metacarpal base. The main portion of the thumb metacarpal is usually subluxated radially and dorsally by the combined pull of the thumb extensors, the abductor pollicis longus, and the adductor pollicis longus.
Rolando fracture
The Rolando fracture involves a Y-or T-shaped split into the trapeziometacarpal joint.
Reduction of a Bennett fracture
In addition to longitudinal traction on the thumb while exerting pressure over the dorsoradial aspect of the metacarpal base, pronation of the distal fragment is important for reduction of a Bennett fracture, as well as for apposition of the volar oblique ligament in trapezial fractures and trapeziometacarpal dislocations.
Management of a Bennett fracture
Closed reduction with percutaneous fixation should generally be attempted, with open reduction being reserved for cases in which residual joint incongruity persists following attempts at closed reduction.
A 20-year-old man comes to the emergency department after falling on the thumb of the dominant right hand during basketball practice. The thumb remained in a “bent back position” despite the coach’s attempt to straighten it. Radiographs of the hand are shown and demonstrate a dorsal dislocation of the thumb. Which of the following is the most appropriate treatment? (A)Closed reduction (B)Dynamic traction splinting (C)Open reduction (D)Percutaneous pin fixation in flexion (E)Serial splinting
(A)Closed reduction
The radiographs show a dorsal dislocation of the thumb. Most metacarpophalangeal (MCP) dislocations of the thumb are dorsal and are reducible. The standard technique is gentle hyperextension of the MCP joint with direct pressure on the dorsal base of the proximal phalanx.
Treatment of most metacarpophalangeal (MCP) dislocations of the thumb
Most metacarpophalangeal (MCP) dislocations of the thumb are dorsal and are reducible. The standard technique is gentle hyperextension of the MCP joint with direct pressure on the dorsal base of the proximal phalanx.
How are dorsal metacarpophalangeal (MCP) dislocations of the thumb reduced?
The standard technique is gentle hyperextension of the MCP joint with direct pressure on the dorsal base of the proximal phalanx.
A median nerve block added to a radial nerve block allows the thenar musculature to relax and loosen its noose. Further wrist flexion can loosen the FPL.
Mechanism of dorsal metacarpophalangeal (MCP) dislocations of the thumb?
The mechanism of the dislocation is a disruption of the volar plate, dorsal capsule, and portions of the collateral ligaments.
How can reduction of a dorsal metacarpophalangeal (MCP) dislocation of the thumb be inhibited?
Reduction becomes more difficult when:
- The volar plate becomes interposed between the metacarpal head and the proximal phalanx. Hyperextension helps extricate the volar plate and allow reduction.
- Reduction can also be inhibited when the flexor pollicis longus (FPL) and the thenar musculature ensnare the metacarpal head like a noose.
Where are the sesamoid bones imbedded?
Inside the volar plate
Determining volar plate disruption (thumb MCP)
Observation of the location of the sesamoid bones, which are imbedded in the volar plate, will give evidence of the location of the disruption.
When to perform open reduction for a dorsal MCP dislocation of the thumb
Open reduction is appropriate if closed reduction is unsuccessful using adequate anesthesia and appropriate reduction maneuvers.
Dorsal vs volar approach for open reduction for a dorsal MCP dislocation of the thumb
Proponents of the dorsal approach avoid endangering the volar digital nerves, which are pushed very close to the skin by the metacarpal head. In contrast, the volar approach allows repair of the volar plate if needed.
28-year-old man who is an amateur motorcycle stunt driver comes to the emergency department because he has progressively worsening pain and numbness in the left hand three hours after injuring the left wrist in a motorcycle misadventure. Radiographs of the wrist are shown (closed right dorsal perilunate, transscaphoid, transulnar styloid fracture-dislocation). He has previously fractured both scaphoids in similar accidents. The scaphoid fractures are not united. An operating room is not available for at least six hours. Which of the following is the most appropriate next step in management?
(A)Closed reduction
(B)Contrast arthrogram
(C)Contrast MRI
(D)Injection of corticosteroid into the left wrist
(E)Plaster splinting
(A)Closed reduction
The critical element is reduction to alleviate the numbness and pain. Splinting follows successful reduction.
The patient described has a closed right dorsal perilunate, transscaphoid, transulnar styloid fracture-dislocation. In the scenario described, with no immediate operating room availability and with worsening pain and numbness, the most appropriate treatment is closed reduction followed by splinting, which can be performed in the emergency department under conscious sedation. When an operating room becomes available, the injuries to ligament and bone can be open repaired or reconstructed
Critical element in treating a closed right dorsal perilunate, transscaphoid, transulnar styloid fracture-dislocation
The critical element is reduction to alleviate the numbness and pain. Can reduce in the ED to alleviate pain before taking to the OR.
A 17-year-old boy is referred to the office by his primary care physician for consultation regarding lack of active flexion of the distal interphalangeal joint of the ring finger of the dominant right hand. Six weeks ago, he sustained an injury to the hand while practicing with his high school football team. Immediately after the injury, the team’s trainer initiated alternating application of hot and cold packs to the hand and gave the patient a finger splint, which he wore intermittently for five weeks. Current physical examination shows a tender mass at the distal interphalangeal joint of the ring finger. A radiograph is shown ( avulsion of the flexor digitorum profundus (FDP) tendon from the distal phalanx). Which of the following is the most appropriate next step?
(A)Fusion of the distal interphalangeal joint
(B)Fusion of the proximal interphalangeal joint
(C)Reduction and fixation
(D)Tendon repair with single-stage tendon grafting
(E)Two-stage tendon reconstruction with implantation of a silicone rod
(C)Reduction and fixation
The patient described has an avulsion of the flexor digitorum profundus (FDP) tendon from the distal phalanx, otherwise known as a jersey finger. This injury most commonly involves the ring finger.
Leddy classification
Classification for avulsion of the flexor digitorum profundus (FDP) tendon from the distal phalanx, otherwise known as a jersey finger.
Jersey finger most commonly involves..
The ring finger
Type I FDP avulsion
In type 1 injuries, the proximal FDP retracts to the palm. These injuries must be repaired within two weeks to avoid a tendon graft.
Type I FDP avulsion treatment
In type 1 injuries, the proximal FDP retracts to the palm. These injuries must be repaired within two weeks to avoid a tendon graft.
Type II FDP avulsion
In Type 2 injuries, the tendon retracts to the level of the proximal interphalangeal (PIP), where it is usually maintained by a distal phalanx bone fragment by the A3 pulley.
Type II FDP avulsion treatment
Type 2 injuries can usually be repaired without the need for a graft iftreated within three months. However, over time, type 2 injuries can convert to type 1 injuries with proximal migration of the tendon to the palm.
Type III FDP avulsion
In Type 3 injuries, the bone fragment prevents tendon retraction proximal to the A4 pulley. Type 3 injuries can usually be repaired without a tendon graft, at any time, even after three months.
Type III FDP avulsion treatment
In Type 3 injuries, the bone fragment prevents tendon retraction proximal to the A4 pulley. Type 3 injuries can usually be repaired without a tendon graft, at any time, even after three months.
How much time to treat FDP avulsion for a type II injury?
3 months
However, over time, type 2 injuries can convert to type 1 injuries with proximal migration of the tendon to the palm.
What traps the tendon in Type II FDP avulsion injuries (finger)
A3:
In Type 2 injuries, the tendon retracts to the level of the proximal interphalangeal (PIP), where it is usually maintained by a distal phalanx bone fragment by the A3 pulley.
What traps the tendon in Type III FDP avulsion injuries (finger)
A4:
In Type 3 injuries, the bone fragment prevents tendon retraction proximal to the A4 pulley.
A 28-year-old professional baseball player comes to the emergency department one hour after he sustained injuries to the index finger of the dominant right hand during a game. A radiograph is shown. Which of the following is the most appropriate management?
(A)Buddy taping the index and long fingers for three weeks
(B)Closed reduction, splinting, and repeat radiography at four weeks
(C)Extension block splinting with early protected motion
(D)Open reduction with rigid screw fixation with early protected motion
(E)Skeletal dynamic traction splinting for three weeks
(D)Open reduction with rigid screw fixation with early protected motion
Condylar fractures of the proximal phalanx are inherently unstable. The patient described has a displaced condylar fracture. The standard of care is open reduction and internal fixation with either screws or Kirschner wire. Screw fixation allows for early active range of motion. Percutaneous pinning or fixation with cannulated screws under C-arm control is a reasonable approach; however, it can be more difficult to obtain reduction using these techniques
Stability of a condylar fractures of the proximal phalanx
Condylar fractures of the proximal phalanx are inherently unstable.
Standard of care for a condylar fracture of the proximal phalanx
The standard of care is open reduction and internal fixation with either screws or Kirschner wire. Screw fixation allows for early active range of motion.
Percutaneous pinning or fixation with cannulated screws under C-arm control is a reasonable approach; however, it can be more difficult to obtain reduction using these techniques
Treatment for non displaced condylar fracture of the PIP
Nondisplaced condylar fractures can be treated with splinting alone. However, displacement is likely and radiographs must be taken frequently to monitor for displacement. Similarly, closed reduction can be performed, but frequent follow-up radiographs are needed
When is skeletal dynamic traction splinting appropriate for proximal interphalangeal (PIP) joint fractures ?
Skeletal dynamic traction splinting is appropriate for severely comminuted proximal interphalangeal (PIP) joint fractures such as those seen with pylon-type injuries
Treatment of severely comminuted proximal interphalangeal (PIP) joint fracture
Skeletal dynamic traction splinting is appropriate for severely comminuted proximal interphalangeal (PIP) joint fractures such as those seen with pylon-type injuries