What procedure will improve the midtarsal locking mechanism?

• A. Evan's calcaneal osteotomy
• B. Dwyer osteotomy
• C. Cotton osteotomy
• D. Lapidus procedure

Answer: (A)

The midtarsal locking mechanism is best enhanced by restoring proper hindfoot alignment and strengthening the transverse arch so the talonavicular and calcaneocuboid joints can press into a stable, locked position during stance. Evan’s calcaneal osteotomy achieves this by creating an opening wedge in the calcaneus to lengthen the lateral column of the hindfoot. This maneuver rebalances the hindfoot, improves the height and tension of the lateral column, and helps realign the midtarsal joints so they can function together as a rigid lever rather than slide open in pronation. In contrast, other options target different aspects: the Dwyer procedure shifts the hindfoot into varus via a medial closing wedge, Cotton osteotomy alters forefoot alignment through a dorsal cuneiform procedure, and the Lapidus fuses the first tarsometatarsal joint. While those can correct related deformities, only Evan’s calcaneal osteotomy directly facilitates a resynchronized midtarsal joint that locks in stance.