DIP Dislocation
Jason J. Stacy
Jeffrey McDaniel
BasicsDescription
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Dislocations of distal interphalangeal (DIP) or 1st interphalangeal (IP) joints
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Mechanism is typically a hyperextension injury of the DIP joint.
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Synonym(s): Jammed finger
Epidemiology
Incidence
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Pure DIP dislocations are uncommon. They are usually accompanied by a bony avulsion fracture.
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Most dislocations are primarily dorsal in direction.
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Volar dislocations are often associated with disruption of the terminal extensor tendon at its insertion point, making management more difficult.
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Simultaneous DIP and proximal interphalangeal (PIP) dislocations are rare, occurring most commonly in ring and small fingers.
DiagnosisHistory
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Mechanism of injury (ie, hyperextension)
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Presence of an obvious deformity (eg, distal phalanx positioned above or below the plane of the middle phalanx)
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Often self-reduced by the patient on the playing field
Physical Exam
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Obvious deformity if not already reduced: Distal phalanx sitting above (dorsal dislocation) or below (volar dislocation) the plane of the middle phalanx.
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Careful examination: Check flexor and extensor function (with the PIP joint held in extension) of the DIP joint and sensation at the tip of the finger.
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Check collateral ligament: Place radial and ulnar stress across DIP joint with joint in full extension and 30 degrees flexion looking for increased laxity.
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Check volar plate: Increased hyperextension of the joint is indicative of a volar plate injury.
Diagnostic Tests & Interpretation
Imaging
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Radiographs: 3 views preferred (anteroposterior, lateral, and oblique views)
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Look carefully for any bony avulsion, especially of the volar plate.
Differential Diagnosis
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Fracture of distal or middle phalanx
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Flexor digitorum profundus (FDP) rupture (ie, jersey finger)
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Extensor mechanism rupture (ie, mallet finger)
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Bony mallet finger (bony avulsion of the insertion of the extensor mechanism at the dorsal base of the distal phalanx)
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Fracture-dislocation
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Collateral ligament disruption
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Chronic instability
Treatment-
Reduction techniques:
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On-field reduction should be attempted to reduce pain and usually is easily performed when done acutely.
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Technique for reduction: Maintaining proximal countertraction to the DIP joint, apply a steady longitudinal traction force of the distal finger. Recreating the injury initially may help in reduction.
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Sometimes sweat causes slick skin, making reductions acutely difficult. Try using a towel or gauze pad for additional grip.
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Reduction may require a digital block if dislocation is prolonged or associated with significant pain.
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Postreduction evaluation:
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Careful examination as above, especially checking neurovascular status
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Postreduction radiographs from at least 2 views
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Complications:
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Dislocation may be irreducible. This is thought to happen for several reasons:
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Trapped volar plate
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FDP entrapment behind a single condyle of P2
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P2 has buttonholed through the volar plate.
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Extensor tendon displacement around the head of P2
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Immobilization:
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Dorsal dislocations should be placed in a splint with the DIP joint in slight flexion (20 degrees) for 1–2 wks.
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Volar dislocations should be placed in a splint with the DIP joint in extension for 8 wks, allowing the extensor tendon to heal.
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Duration of immobilization depends on degree of joint stability.
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When splinting, use caution with regard to the dorsal skin segment between the extensor crease and the nail fold because pressure can cause necrosis.
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P.123
Additional Treatment
Referral
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A referral to an orthopedic surgeon or hand specialist should be made when the dislocation is irreducible or an open injury has occurred with joint exposure.
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In addition, chronic dislocations, FDP tendon ruptures, and unstable collateral ligaments should be referred to a specialist.
Additional Therapies
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Start range-of-motion (ROM) exercises after splint removal.
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Use both active and passive ROM initially.
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Start resisted ROM as soon as active and passive motions are pain-free.
Surgery/Other Procedures
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Closed reduction and percutaneous pinning (CRPP): Some degree of joint instability may require immobilization with use of a Kirschner wire for stabilization.
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Open reduction:
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May be required in a chronically (>3 wks) dislocated or subluxated joint to remove scar tissue and release tension to facilitate reduction.
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Use of a Kirschner wire depends on degree of stability.
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Additional Reading
Browner BD, et al. Skeletal trauma: Basic science, management, and reconstruction, vol. 2, 3rd ed. Philadelphia: Saunders Publishing, 2003.
Bucholz RW, et al. Rockwood and Green's fractures in adults, vol. 1, 6th ed. Philadelphia: Lippincott Williams & Wilkins, 2006.
Eiff MP, Hatch RL, Calmbach WL. Fracture management for primary care: finger fractures. Philadelphia: WB Saunders, 1998.
Green DP, Strickland JW. Orthopaedic sports medicine: principles and practice, the hand. Philadelphia: WB Saunders, 1994.
Palmer RE. Joint injuries of the hand in athletes. Clin Sports Med. 1998;17:513–531.
Wang QC, Johnson BA. Fingertip injuries. Am Fam Physician. 2001;63:1961–1966.
CodesICD9
834.02 Closed dislocation of interphalangeal (joint), hand
Clinical Pearls
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Athlete can return to play immediately if dislocation is uncomplicated and reduced and the athlete is allowed to play with a splint.
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Thumb IP dislocations should be treated exactly the same as DIP dislocations.