Computed Tomography Assessment of Peroneal Tendon Displacement and Posteromedial Structure Entrapment in Pilon Fractures.

Abstract

To determine the proportion of (1) peroneal tendon displacement (PTD) and posteromedial structure entrapment (PMSE) cases in a sample of pilon fractures, (2) missed diagnoses of PTD and PMSE on computed tomography (CT) by radiologists and attending orthopaedic trauma surgeons, and PTD and PMSE cases by (3) OTA/AO classification, and (4) fibular fracture. Retrospective cohort review. Regional level 1 Trauma Center. Two hundred patients treated between July 2008 and November 2014. Axial and reconstructed CT images were used in bone and soft tissue windows to identify PTD and PMSE. Medical charts were reviewed to identify OTA/AO fracture classification, the presence of concomitant fibular fracture, whether radiologist CT interpretation noted PTD or PMSE, and whether attending orthopaedic trauma surgeons' operative notes mentioned recognition of and management of PTD or PMSE. From the retrospective review of CT, PTD was identified in 11.0% and PMSE in 19.0% of all pilon fractures. Of the 22 patients with PTD, 59.1% sustained a concomitant fibular fracture and 90.9% sustained a 43-C fracture. Patients with PTD sustained more 43-C fractures (90.9% vs. 62.9%) but significantly fewer fibular fractures (59.1% vs. 80.3%; P = 0.023) than patients without PTD. Of the 38 patients with PMSE, 81.6% sustained a fibular fracture and 86.8% sustained a 43-C fracture. PMSE was more common in patients with 43-C fractures (86.8% vs. 61.1%). The final preoperative radiologist CT interpretation commented on PTD and PMSE in 50.0% of cases. Higher energy pilon fractures (43-C) are associated with higher incidence of PMSE and PTD. Concomitant fibula fracture may play a protective role in PTD in the setting of pilon fractures. Both attending radiologists and attending orthopaedic trauma surgeons frequently fail to recognize the diagnoses of PTD and PMSE. Prognostic level III. See Instructions for Authors for a complete description of levels of evidence.