Metatarsophalangeal Joint Instability: Anatomy and Physiopathology.

Metatarsophalangeal (MTP) instability is a common cause of metatarsalgia of the lesser toes. Instability often presents as pain in the plantar forefoot, progressing to coronal and transverse plane malalignment. MTP joint dislocation can develop in some cases. The plantar plate plays an integral role in MTP joint stabilization, and injury to the plantar plate is the main contributor to the instability noted at the MTP joint.