Review Question - QID 890

The radiographs shown in Figures A and B demonstrate adult-acquired flatfoot deformity secondary to posterior tibial tendon dysfunction. Achilles tendon contracture will likely be present.

In patients with this adult-acquired flatfoot deformity, the medial longitudinal arch collapses, the subtalar joint everts and the heel assumes a valgus position. As a result of the hindfoot valgus, the Achilles tendon is held lateral to axis of rotation of subtalar joint and begins to act as an evertor of the calcaneus. Untreated deformity can lead to a fixed equinus deformity of the hindfoot and an Achilles tendon contracture.

Myerson et al. review the etiology, classification, evaluation, and treatment of posterior tibial tendon dysfunction in his ICL.

Pinney et al. point out in their CCR that when testing ankle dorsiflexion, the hindfoot must be held in a neutral position to allow the true extent of equinus contracture become apparent.

Figure A demonstrates an adult-acquired flatfoot deformity. Note the uncovering of the talar head on the AP radiograph, and decreased distance between the medial cuneiform and floor on the lateral radiograph indicating collapse of the medial longitudinal arch.