Pilon variant posterior malleolar (PVPM) fractures significantly disrupt joint congruency and cause tibiotalar instability. They are often underestimated and inadequately treated.

This study assessed the outcomes of surgical treatment of this subtype of malleolar fracture, and examined the importance of computed tomography (CT) in diagnosis and surgical treatment.

CT images and radiographs of 67 patients with trimalleolar ankle fractures were retrospectively analyzed. Fourteen patients (6 women and 8 men) were studied. The mean age was 37.7 (range, 21–58) years, and mean follow-up period was 17.1 (range, 12–24) months. All patients underwent open reduction. Reconstruction of the joint surface was assessed with postoperative CT images. The outcomes were assessed with the American Academy of Orthopaedic Surgeons (AAOS) and Osteoarthritis (OA) scoring systems.

The ratio of PVPM fractures to trimalleolar ankle fractures was 20.1%. Postoperative CT images demonstrated that anatomic reconstruction was achieved in 11 patients. The mean AAOS scores were 85.6 in Type 1 and 81.1 in Type 2 cases. The mean OA scores were 1 in Type 1 and 1.1 in Type 2 cases (P>0.05). The only statistically significant difference between the 2 groups was in osteochondral impaction (P<0.05).

CT imaging is essential for the accurate diagnosis and management of PVPM fractures. Posteromedial and posterolateral incisions enable direct exposure, and therefore facilitate joint surface reconstruction.

Level IV. Retrospective study.