Histology of the volar plate of the thumb metacarpophalangeal joint.

The histology of the volar plate of the thumb MCPJ differs significantly from the conventional understanding of the volar plate, based on the volar plate of finger proximal interphalangeal joints. The difference is likely due to the presence of the sesamoids, which confer additional stability, reducing the need for a specialized trilaminar fibrocartilaginous structure with the lateral check-rein ligaments found in the volar plate of finger proximal interphalangeal joints to confer additional stability.