- See:
- Differential Dx of PIP Injuries
- Fracture Dislocations of the PIP Joint
- Phalangeal Injury
- Discussion:
- anatomy of the injury:
- volar plate is always detached (usually from middle phalanx) in PIP dorsal dislocations;
- distal avulsion of volar plate in dorsal PIP dislocations makes entrapment of plate w/in the joint unlikely (in contrast to MP joint in which complex dorsal dislocations prevent closed reduction);
- an irreducible dislocation of PIP joint is probably rotary PIP subluxation:
- volar plate maintains its attachmnets to the proximal phalanx & its lateral attachments to the accessory collateral ligament;
- collateral ligaments may also be ruptured at the time of injury;
- classification of acute injuries:
- type I - hyperextension injury
- volar plate avulsion from middle phalanx base, ligament split, and the joint surface intact;
- finger immobilized in a dorsal splint w/ 20-30 deg of flexion for 10 to 21 days;
- after 2-3 weeks, start on an active flexion program using buddy tapping;
- type II - dorsal dislocation
- major ligament injury
- finger immobilized in a dorsal splint w/ 20-30 deg of flexion for 10 to 21 days;
- after 2-3 weeks, start on an active flexion program using buddy tapping;
- type III: fracture dislocation:
- proximal dislocation w/ the middle phalanx sheared away;
- stable - small fracture w/ less than 40% of the middle phalanx base
- unstable - frx fragment involves > 40% of joint surface;
- try to closed reduction, placing the joint in 75 deg flexion;
- w/ congruent reduction, reduce amount of flexion over over 4 to 5 weeks;
- chronic PIP dorsal dislocations:
- leads to chronic volar plate laxity and hyperextension deformity;
- may interfere with finger f(x) or result in swan neck deformity;
- operative treatment:
- requires advancement and reattachment of volar plate;
- plication of local tissue;
- reconstruction of collateral ligament & volar plate;
- Reduction & Treatment:
- hyper-extension, traction, and then gentle flexion will usually allow reduction;
- simple dislocations:
- early protected ROM allows earliest return to full function and prevents stiffness;
- most patients will require immobilization for up to one week until majority of the pain subsides;
- once patient can tolerate digit range of motion, then the digit should be buddy tapped and allowed full ROM;
- fracture - dislocations:
- extension block casting:
- if collateral ligaments are intact, the reduction will be stable;
- early mobilization w/ buddy tapping w/ limited extension for 3-6 weeks is sufficient for stable fractures;
- external fixation:
- volar plate arthroplasty:
- if joint is unstable due to collateral ligament disruption, consider direct repair of collateral ligament as well as volar plate
Chip Avulsions and Ruptures of the Palmar Plate in the PIP
Fracture dislocations of the proximal interphalangeal joint.