INTEGRITY OF THE FIRST METATARSOPHALANGEAL JOINT - A BIOMECHANICAL ANALYSIS

Five fresh-frozen cadaver feet obtained from traumatic amputations wer e tested during hyperdorsiflexion stress of the first metatarsophalang eal joint. Three different types of injury were observed: (1) rupture of the capsule proximal to the sesamoids, (2) rupture of the plantar p late distal to the sesamoids, and (3) rupture of the capsular structur es medially, allowing a lateral swing of the sesamoids around the meta tarsal head. Incomplete dislocation can be associated with significant damage to the plantar plate and other soft tissues of the foot.