Indications Provides exposure to subtalar joint talonavicular joint calcaneocuboid joint Indications triple arthrodesis Internervous Plane Between peroneus tertius (deep peroneal n.) peroneus brevis (superficial peroneal n.) Approach Position supine with bump under buttock partial exsanguination Incision make a 8-10 cm curved incision begin incision over dorsal-lateral talonavicular joint extend posteriorly over the sinus tarsi (soft tissue depression just anterior to lateral malleolus) incise obliquely to point 2.5 cm below tip of lateral malleolus Superficial dissection incise fascia and divide inferior extensor retinaculum in line with incision ligate veins crossing operative field mobilize small flaps (large flaps may necrose) incise deep fascia and extensor retinaculum in line with incision careful not to damage peroneus tertius and extensor digitotum longus in the superior (distal) part of the incision expose peroneus tertius and EDL and retract medially in inferior part of incision expose peroneal tendons and retract inferior Deep dissection Partially resect fat pad over sinus tarsi with sharp dissection (leave attached to skin flap) Identify and detach origin of extensor digitorum brevis under fat pad Reflect extensor digitorum brevis distally Identify and incise dorsal capsule of talocalcaneonavicular joint Identify and incise capsule of calcaneocuboid joint Incise peroneal retinacula and reflect peroneal tendons anteriorly Identify and incise capsule of posterior talocalcaneal joint Dangers Skin flap necrosis keep skin small and thick avoid sharp curves Extensor digitorum longus tendon Peroneus brevis tendon