Incidence and MR imaging features of fractures of the anterior process of calcaneus in a consecutive patient population with ankle and foot symptoms

Abstract

To determine the incidence, appearances and associated injuries of fractures affecting the anterior process of calcaneus from a general population with foot and ankle symptoms. A retrospective review of foot and ankle MR imaging procedures was performed for detection of cases with a fracture affecting the anterior process of calcaneus over a four year period. Radiographs, MR imaging studies, radiology reports, medical records, and operative notes were reviewed. Imaging analysis included fracture pattern, displacement, associated fractures, and presence of tendon and ligamentous injuries. The incidence of anterior process of calcaneus fracture on MR imaging was 0.5% (14/2577). Fractures were more common in female subjects (71%, 10/14). Fracture orientation was predominantly vertical (93%, 13/14). No comminuted fractures were seen and only three fractures were displaced. Three of the eight MR imaging evident fractures of anterior process of calcaneus were seen on radiographs. Associated fractures of the talus (n=5), navicular bone (n=3), cuboid (n=2), and calcaneal body (n=1) were noted. Associated injuries to the anterior talofibular ligament (n=3) and tears of the peroneus brevis (n=3) and peroneus longus (n=1) tendons were present. All fractures were treated non-operatively. Two patients had subtalar joint steroid injection for symptomatic relief. Fractures of the anterior process of the calcaneus are uncommon in MR examinations of a general population of patients with foot and ankle symptoms. Although anterior process of calcaneus fractures are rare, there was a moderately high incidence of associated bone and soft-tissue injuries.