The histologic anatomy of the volar plate.

The volar plate (VP) is critical to the stability of the proximal interphalangeal joint. This study clarifies the macro- and micro-architectural structure of the VP and correlates these findings with its functional properties. Microscopic evaluation of cadaver specimens revealed a trilaminar structure of the VP with differential orientation and organization of collagen fibers in the volar, central core, and dorsal check rein sections of the plate. This description differs from the existing literature and adds to the understanding of the functional properties of the VP. The most important finding is a dense "basket weave" of collagen fibers oriented in 2 perpendicular planes within the central core of the VP. This orientation may contribute primarily to the resistance of the VP to both longitudinal and torsional stress. This study adds to the understanding of the histologic basis for the function of the VP and the mechanisms involved in its injury.