Fig. 3.

a–d The US pictures were taken 2 cm proximal and distal of the DM-line and directly at the level of the DM-line; the red circles are landmarks visualizing the flexor retinaculum; The yellow head arrow mark the surgical portal at the US pictures; TP tibial posterior, FDL flexor digitorum longus; V posterior tibial veins and perforating vein at the 2 cm distal Dellon line, A posterior tibial artery, TN tibial nerve, MPN medial plantar nerve, LPN lateral plantar nerve, FHL flexor hallucis longus muscle. (Color figure online)