Figure 12.

Abnormalities of the posterior tibialis tendon (PTT) in a 64-year- old woman with adult acquired flat foot deformity. Axial fat-suppressed T2-weighted magnetic resonance images of the ankle demonstrate abnor- mally enlarged PTT (arrow, A) with increased intrasubstance signal (arrow, B), indicative of tendon degeneration and intrasubstance tearing; prominent tenosynovitis with fluid distending PTT tendon sheath (B); osseous hyper- trophy and a bone marrow edema like signal (asterisk in A) in the medial malleolus representing reactive osteitis. Note intact superomedial bundle of spring ligament (arrowheads in B) coursing between the talar head and PTT. In b, note incomplete bone coverage of the talar head by the navicular in keeping with pes planus