Fracture pattern and fixation type related to loss of reduction in bicondylar tibial plateau fractures.

INTRODUCTION: Bicondylar tibial plateau fractures can be treated with locked plating applied from the lateral side with or without additional application of a medial plate (dual plating). Recent studies demonstrate that these injuries can be sub-grouped based upon their morphology by computed tomography (CT). The purpose of this study is to evaluate the relationship between fracture pattern, method of fixation and loss of reduction in bicondylar tibial plateau fractures.

PATIENTS AND METHODS: Preoperative CT scans and postoperative plain films were evaluated on a consecutive series of bicondylar tibial plateau fractures. Fracture patterns were classified by CT. Angular alignment was measured immediately postoperatively and again at clinical and radiographic union to assess loss of reduction.

RESULTS: A total of 140 patients were studied. Sixty-six (47%) had a single large medial fragment with the articular surface intact, 19 (14%) had a medial articular fracture line with a mainly sagittal component and 55 (39%) had a coronal fracture through the medial articular surface. A total of 129 patients had been treated with lateral locked plating alone whilst 11 patients (all with a coronal fracture of the medial condyle) underwent dual plating. There was little loss of reduction (median subsidence 0.5°) when lateral locked plating was employed alone in patients with a single medial fracture fragment or with a sagittal medial fracture line. When lateral locked plating was used in the presence of a medial coronal fracture line, there was a significantly higher rate of subsidence (median 2.0°) compared to those with no medial fracture line (p=0.002). Patients with coronal fracture lines treated with dual plating had significantly less loss of reduction that those treated with lateral locked plating (p=0.01).

CONCLUSIONS: Most patients with bicondylar tibial plateau fractures do well when treated with lateral locked plating. However, those with a medial coronal fracture line tend to have a higher rate of subsidence and loss of reduction when lateral locked plating is employed alone. These fractures may be better treated with dual plating if the soft tissues allow.

LEVEL OF EVIDENCE: Level III (retrospective comparative study).