Plantar plate of metatarsophalangeal joint

The plantar plate of metatarsophalangeal joint (Plantar metatarsophalangeal ligament in Terminologia Anatomica) is a firm, flexible fibrocartilaginous structure that occupies a ventral and central position in the metatarsophalangeal joints. Proximally, it is thinner and loosely attached to the periosteum near the metatarsal neck. Distally, it is thicker and more firmly attached to the base of the proximal phalanx, becoming thinner in its central portion adjacent to the enthesis, where there is often a juxta-insertional groove. It can reach 20mm x 9mm x 2mm (length x width x thickness)

The plantar plate is suspended by the proper and accessory collateral ligaments, and interconnected laterally by the deep transverse intermetatarsal ligament. The interosseous tendons are located at the junction of the deep transverse ligament with the plantar plate. The flexor tendon of the fingers is lo- cated on the lower border of the plantar plate. 

On the lateral borders of the distal insertion of the plantar plate, this plate is closely entwined with the joint capsule, the proper collateral ligaments, and the interosseous tendons, which makes it hard to clearly distinguish between these structures in a routine examination. This anatomical unit, formed by the proximal phalanx, the plantar plate and their insertional connections, is described as phalangeal apparatus, a term adapted by the authors and referred to herein as “plantar plate insertion complex”, due to the difficulty in clearly distinguishing between the various structures notably  in the MRI study.