- 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;
- Treatment w/ Intraosseous Wiring:
- see: interosseous wiring discussion;
- this technique may be indicated for volar plate avusions which occur detach an articular fragment;
- 20 gauge wire is passed either thru two bone holes or through the junction of the volar plate and the fragment (if the fragment is small), and is then passed through parallel holes adjacent to the fracture surface on the phalanx;
- the wires should emerge on the dorsal surface of the middle phalanx, over the triangular ligament near the mid line;
- the wires are tightened down, securing the fragment;
- ref: Intraosseous Wiring of the Digital Skeleton.
- Case Example:
- 30-year-old male who sustained multiple dorsal PIP dislocations of the middle finger which resulted in a hyper-extension deformity and gross instability;
The proximal interphalangeal joint volar plate II. A clinical study of hyperextension injury.
Chip Avulsions and Ruptures of the Palmar Plate in the PIP
Volar plate arthroplasty for the proximal interphalangeal joint. A ten years' review. Eaton RG. J Hand Surg. 1980;5:260-268.
The proximal interphalangeal joint volar plate. I. Bowers. J Hand Surg. 1980;5:79.