Acute Phase
Rehabilitation Program
Occupational Therapy
Finger metacarpophalangeal (MCP) joint collateral ligament sprains should not be overtreated. First-degree sprains may require a brief period of protection, usually consisting of buddy taping for 2-3 weeks. Second-degree sprains are immobilized in mid flexion for 3 weeks.
Finger MCP joint hyperextension injuries may be treated by gently flexing the proximal phalanx and immobilizing the MCP joint in 30° of flexion for 2-3 weeks. A dorsal extension-block splint protects the healing volar plate while allowing active flexion of the finger. Early protected motion minimizes postinjury stiffness.
Thumb MCP joint hyperextension injuries ("locked MCP joint") are immobilized in 20° MCP joint flexion for 3 weeks.
After closed reduction, a dorsal extension-block splint, including the wrist, is used for at least 3 weeks in MCP joint dorsal dislocations. Active motion within the splint is started during the first week. Following closed reduction, the thumb is immobilized in a forearm-based thumb spica splint or cast with the MCP joint in extension for 4-6 weeks in thumb MCP joint volar dislocations.
Thumb radial collateral ligament injuries may be treated in a forearm-based or hand-based thumb spica cast for 4 weeks.
Surgical Intervention
After open reduction surgical repair, postoperative immobilization and therapy are similar to those that are recommended after closed reduction. In finger MCP joint collateral ligament injuries, surgical repair is indicated for gross instability (third-degree sprain) or a significantly displaced or rotated avulsion fracture.
MCP joint complex dorsal dislocations require open reduction in the operating room. This reduction may be accomplished with a palmar or dorsal approach. A dorsal longitudinal incision affords easy visualization of the interposed volar plate and avoids the digital neurovascular bundles that are more susceptible to injury with the palmar approach.
Volar MCP joint dislocations are extremely rare. The volar plate or dorsal capsule may be interposed into the joint, which usually requires open surgical reduction. Immobilization for 3-4 weeks in extension is recommended after successful reduction.
In thumb MCP joint dorsal dislocations, open reduction through a dorsal approach is indicated for failed closed reduction. [12] A dorsal approach is also used for failed closed management of a locked thumb MCP joint injury. In thumb MCP joint volar dislocations, surgical repair should be considered for chronic dislocations or when postreduction radiographs demonstrate persistent volar subluxation of the MCP joint. In thumb radial collateral ligament injuries, significant laxity (>30°) or volar subluxation is an indication for surgical repair.
A review of 21 patients with metacarpophalangeal dislocations reported that operative time was longer for the patients using the volar approach when compared to the dorsal approach and that 42% of the patients who underwent the volar approach required a second dorsal approach. [13]
Consultations
Immediate consultation with an orthopedic or hand surgeon is indicated for open or irreducible dislocations or when neurovascular compromise of the digit is present. After successful closed reduction, follow-up within 1 week should be arranged with an orthopedic or hand surgeon.
Recovery Phase
Rehabilitation Program
Occupational Therapy
After the appropriate immobilization period, progressive hand therapy is initiated.
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Finger MCP joint collateral ligament: Second- and third-degree sprains are protected with buddy taping for an additional 3 weeks.
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Finger MCP joint hyperextension injuries: The injured digit is buddy taped to an uninjured finger for an additional 2-3 weeks.
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MCP joint dislocations: Progressive motion and gradual weaning from the splint are performed over 3 weeks.
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Thumb radial collateral ligament: Protected motion in flexion/extension and gradual weaning from the splint are performed over 2 weeks.
Surgical Intervention
Significant collateral ligament laxity that interferes with hand function may require surgical reconstruction after an appropriate time period for normal healing has lapsed. Excessive joint contractures unresponsive to occupational therapy may require surgical release.
Prevention
Although no studies exist with regard to efficacy, most practitioners recommend appropriate buddy taping of the injured finger to an uninjured digit during forceful activities, especially contact sports, to help prevent reinjury.
Return to Play
As with most injuries return to play in patients with metacarpophalangeal (MCP) joint dislocation will vary somewhat by the injury and desired activity. Some athletes will be able to return immediately as long as the injury can be adequately protected in a splint or cast. After the acute MCP joint injury has healed (usually 3-6 wks), the injured finger can be buddy taped for 1-3 weeks for additional protection and comfort. Some MCP joint injuries may require up to 3 months for full return to sporting activity if they cannot be protected or if the desired sport requires full use of the injured finger.
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Metacarpophalangeal joint dislocation of the small finger. Posteroanterior radiograph demonstrates loss of joint space.
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Metacarpophalangeal joint dislocation of the small finger. Oblique radiograph best demonstrates dorsal dislocation of proximal phalanx.
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Metacarpophalangeal joint dislocation of the small finger. Dorsally dislocated proximal phalanx is obscured by other digits. Note that the small finger metacarpal sits palmar to the other metacarpals.
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Closed reduction
