Fifth metatarsophalangeal joint

The fifth metatarsophalangeal joint is the articulation between the head of the fifth metatarsal and the base of the proximal phalanx of the fifth toe. The joint is a synovial condyloid joint, allowing flexion, extension, abduction, and adduction.

Key anatomical structures include:

• Articular surfaces: The rounded head of the fifth metatarsal and the concave base of the proximal phalanx.

• Joint capsule: Encloses the joint and is reinforced dorsally and plantarly.

• Plantar plate: A fibrocartilaginous structure on the plantar aspect, providing stability and resisting hyperextension. It is anchored proximally to the metatarsal head and distally to the base of the proximal phalanx, with strong attachments to the plantar fascia and collateral ligaments.[

• Collateral ligaments: Medial and lateral ligaments stabilize the joint and merge with the plantar plate.[2]

• Deep transverse metatarsal ligament: Connects the plantar plates of adjacent lesser toes, contributing to transverse stability.

• Tendons: The flexor digitorum longus and brevis pass plantar to the joint, while the extensor digitorum longus and brevis cross dorsally.