Internal fixation of calcaneus fractures: an anatomical study of structures at risk

This study examines the risk of injury to medial soft-tissue structures during the fixation of calcaneal fractures performed through a lateral approach. An L-shaped lateral incision was performed on 10 fresh cadaver feet. The calcaneus was divided into three zones for study. Ten K-wires were inserted in a standard configuration from a lateral starting point extending through the medial cortex. The feet were dissected medially to measure the distance from each exiting K-wire to the medial and lateral plantar vessels, the calcaneal branch of the posterior tibial nerve, and the tendons of the flexor hallucis longus, flexor digitorum longus, and posterior tibialis. The mean risk of injury to these medial structures was calculated for each lateral insertion site. Wires placed in the subchondral bone of the posterior facet or anterior to the critical angle of Gissane were determined to be at high risk of injury to the medial soft tissues. Structures at risk included the medial and lateral plantar nerves and vessels and the flexor hallucis longus tendon. Caution should be exercised when inserting K-wires, drills, and screws into high-risk areas to avoid iatrogenic injury to the medial structures.