Adult acquired flatfoot disease - chronic tibialis posterior tendon rupture
Presentation
Ankle and foot pain.
Patient Data
Pes planovalgus. Reduced calcaneal pitch. Medial talar head excursion. Collapsed sinus tarsi and calcaneofibular interval. Increased hindfoot valgus angle.
No ankle joint effusion. Subchondral marrow signal at medial and lateral aspects of the talar dome. Calcaneofibular impaction characterized by subchondral cysts.
Focal full-thickness chondral loss at the talocalcaneonavicular joint. Marked thickening of the dorsal talonavicular joint capsule with capsular edematous ossicle.
Focal full-thickness chondral loss at the navicular-intermediate cuneiform articulation.
Posterior subtalar joint articular cartilage is preserved. Moderate effusion of posterior subtalar joint, containing a small intra-articular ossicle.
Torn superomedial component of the spring ligament. Intact medial and inferior plantar components. Marked thickening of distal deltoid tibiocalcaneal ligament. Attenuated tibiospring and deltoid tibionavicular ligaments. Chronic high grade to complete tears of ATFL, CFL and PTFL. Mild scarring and thickening of AITFL. No tear to the interosseous membrane or PITFL.
Tibialis posterior is torn and retracted away from its navicular insertion. Some of its plantar slips are also torn, forming a rounded retraction ball below the talar head. Peroneus brevis high-grade tear. No other tendon tear seen.
Severe atrophy of abductor hallucis brevis and abductor digiti minimi. Mild atrophy seen in the rest of the visualized hindfoot muscles.
Case Discussion
This is an example of adult acquired flat footdisease with pes planovalgus secondary to a known chronic tibialis posterior tendon rupture. There is also a partially torn spring ligament complex, which is also going to be contributing to the alignment abnormality. Associated hindfoot and midfoot arthritic change as well as prior ligamentous injuries are also present.