Extension splinting of palmar plate avulsion injuries of the proximal interphalangeal joint.

Hyperextension injuries of the proximal interphalangeal joint have traditionally been immobilized in flexion. This may lead to a proximal interphalangeal flexion contracture of the joint. In an effort to prevent flexion contracture and to simultaneously avoid hyperextension laxity, we have immobilized these injuries in zero degrees of extension for 7 to 10 days. Immobilization is followed by buddy taping and active range of motion until 3 weeks after injury. Protective buddy taping is used until the 6-week point. We report our results using this treatment for only palmar plate avulsion fractures. We did not include proximal interphalangeal joint injuries associated with dorsal dislocation or major collateral ligament injury. Twenty-two of 45 patients were available for follow-up evaluation. Length of follow-up averaged 30 months (range, 6 to 36 months). A high percentage of patients had good or excellent results. In no patient did hyperextension laxity develop and in only one was there a flexion contracture. On the basis of these results, we recommend this treatment protocol for hyperextension injuries of the palmar plate of the proximal interphalangeal joint associated with small avulsion fractures.