Plantar plate of proximal interphalangeal joint

The plantar plate of the proximal interphalangeal (PIP) joint of the toe is a fibrocartilaginous structure located on the plantar aspect of the proximal interphalangeal joint.

It is analogous in composition and function to the plantar plate of the metatarsophalangeal (MTP) joints, being primarily composed of dense, longitudinally oriented collagen bundles with a central region that withstands tensile and compressive forces during gait and toe-off.The plate is thickest centrally and tapers distally, where it becomes more ligamentous in character, with fewer chondrocytes and more fibroblasts.

The plantar plate is anchored proximally to the base of the proximal phalanx via interdigitating collagen bundles, forming a robust enthesis. It merges laterally with the collateral ligaments and transversely with the deep transverse intermetatarsal ligament, contributing to the stability of the joint and preventing dorsal subluxation of the phalanx. The plantar plate also serves as the distal attachment for the plantar fascia, integrating with the digital processes of the deeper layer of the plantar aponeurosis, and is closely associated with the flexor tendons.