THE HISTOLOGIC ANATOMY OF THE VOLAR PLATE

The volar plate (VP) is critical to the stability of the proximal inte rphalangeal joint. This study clarifies the macro- and micro-architect ural structure of the VP and correlates these findings with its functi onal properties. Microscopic evaluation of cadaver specimens revealed a trilaminar structure of the VP with differential orientation and org anization of collagen fibers in the volar, central core, and dorsal ch eck rein sections of the plate. This description differs from the exis ting literature and adds to the understanding of the functional proper ties of the VP. The most important finding is a dense ''basket weave'' of collagen fibers oriented in 2 perpendicular planes within the cent ral core of the VP. This orientation may contribute primarily to the r esistance of the VP to both longitudinal and torsional stress. This st udy adds to the understanding of the histologic basis for the function of the VP and the mechanisms involved in its injury. Copyright (C) 19 98 by the American Society for Surgery of the Hand.