The Mau osteotomy is oriented in which direction?

• A. Dorsal distal to plantar proximal
• B. Dorsal proximal to plantar distal
• C. Ventral to dorsal
• D. Medial to lateral

Answer: (A)

The Mau osteotomy is an oblique plantarflexion correction of the first metatarsal neck, with the cut running from the dorsal-distal edge to the plantar-proximal edge. This orientation lets the distal fragment rotate plantarward relative to the proximal fragment when the osteotomy is closed, effectively plantarflexing the metatarsal head. That plantarflexion lowers the elevated first ray and helps correct associated hallux valgus.

If the osteotomy were oriented in other directions, the rotation would not produce the desired sagittal-plane plantarflexion, so the intended correction wouldn’t be achieved.