Lateral Wall Displacement of Calcaneal Fracture Leading to Peroneal Tendon Dislocation: Effect of the Distance of Lateral Wall Displacement on the incidence of Peroneal Tendon Dislocation

Abstract

Peroneal tendon dislocation accompanying an intra-articular calcaneal fracture is uncommon; however, such dislocations are often missed in the acute phase. Although risk factors have been reported, the correlation between the degree of lateral wall displacement of the fractured calcaneus and the incidence of peroneal tendon dislocation remains unclear. We retrospectively analyzed computed tomography scans of 61 patients who had calcaneal fractures to examine peroneal tendon dislocation and the association with degree of lateral wall displacement and presence of fleck signs, between peroneal tendon dislocation and non-dislocation cases. Peroneal tendon dislocation was observed in 11.5 % (7/61) of the scan of patients with acute calcaneal fractures. The mean measurement of lateral wall displacement of the calcaneus was −3.3 (−11.1 to 8.9) mm. The fleck sign on radiographic images was evident in two cases (3.3 %), whereas the fleck sign on scans was evident in three cases (4.9 %). The mean measurement was significantly greater in cases with peroneal tendon dislocation than in those without dislocation (3.0 vs −4.1 mm, P<.05). The incidence of peroneal tendon dislocation and the lateral wall distance were significantly associated with the severity of calcaneal fractures, according to the Sanders classification system. The area under the curve generated for the medial deviation of the receiver operating characteristic curve was 0.976 and the cut-off value was 0.9. This study showed that lateral wall displacement is related to peroneal tendon dislocation and that the measurement of displacement using computed tomography scans can be a useful indicator of peroneal tendon dislocation.