Fig. 4

Whole appearance of the joint capsule. a The whole flipped continuous capsule remaining attachment to the calcaneus is shown. The black dotted area indicates the attachment of the joint capsule. The white dotted area indicates the insertion of the posterior tibialis (PT) tendon. Red arrows indicate the corresponding bone and detached capsule. b The inner appearance of the continuous capsule is shown after being completely detached from the calcaneus. The continuous capsule consists of 3 different tissues: fatty tissue (asterisk), fibrous tissue (black circle), and cartilaginous capsule (dagger). The fatty tissue extended medially and attached between the fibrous and the cartilaginous tissue (black square). c The outer appearance of the continuous capsule. The part of the fibrous tissue (black circle) and the cartilaginous tissue (dagger) formed the sheath floor of the PT tendon (white arrows), and the part of the fibrous tissue (section mark) formed the sheath floor of the flexor digitorum longus tendon (black arrows). Prox, proximal; Dist, distal; Plan, plantar; Dors, dorsal; PT, insertion of the posterior tibialis tendon; Nav, navicular; ST, sustentaculum tali; double dagger, capsule corresponding to sustentaculum tali