In anterior cavus foot deformity, the apex occurs at which joint?

• A. 2nd metatarsocuneiform joint
• B. 1st metatarsocuneiform joint
• C. 1st tarsometatarsal joint
• D. Calcaneocuboid joint

Answer: (B)

The main idea is where the highest point of the arch—the apex of the cavus deformity—lies, because that tells you where the forefoot is driving the deformity and where correction should be focused. In anterior cavus, the apex is in the forefoot, near the first ray. That means the first metatarsocuneiform joint is the location where the arch height concentrates, reflecting plantarflexion of the first ray relative to the hindfoot. This forefoot-dominant apex explains the high medial arch seen in anterior cavus and guides surgical planning toward addressing the first ray at that joint, such as a dorsiflexion correction at the first metatarsocuneiform joint. Joints at the second ray, or more proximal tarsometatarsal joints, point to different patterns of deformity, and a calcaneocuboid (hindfoot) involvement would indicate a different overall mechanics.