The proximal interphalangeal joint volar plate. II: a clinical study of hyperextension injury.

The surgical anatomy and clinical course of the pure hyperextension injury of the proximal interphalangeal (PIP) joint is described based on observations in 12 patients coupled with 15 cases from the literature and vascular injection study of the volar plate. The conclusions are (1) virtually all pure hyperextension injuries produce a rupture of the volar plate at the distal end and (2) such a rupture, when not associated with a marginal metaphyseal avulsion fracture, is not easily diagnosed and is likely to eventuate in a chronic posttraumatic hyperextension deformity because relatively avascular injured tissue is insufficiently immobilized.