OBJECTIVES: This study was designed to describe the fracture patterns and early results of treatment of posterior shearing tibial plateau fractures.

DESIGN: Retrospective case series.

SETTING: Tertiary care hospital.

PATIENTS: Thirteen patients identified from prospective trauma database with posterior shearing tibial plateau fractures.

INTERVENTION: Open reduction and internal fixation through a posterior approach to the knee.

MAIN OUTCOME MEASUREMENTS: Functional outcome assessed by Musculoskeletal Functional Assessment score and Visual Analogue Scale pain scores. Clinical and radiographic outcome.

RESULTS: A consistent fracture pattern was identified with a primary, inferiorly displaced posteromedial shear fracture with variable amounts of lateral condylar impaction. The average duration of clinical patient follow-up was 20 (range, 13-27) months. All fractures healed after index surgery. Two complications (1 wound dehiscence and 1 flexion contracture) were all managed nonoperatively. Three independent surgeons graded patients' articular reduction, with good interobserver reliability (intraclass correlation coefficient = 0.82). The average Musculoskeletal Function Assessment dysfunction score for the 9 patients who responded was 19.5/100, and average resting Visual Analogue Scale pain score was 1.8 cm/10 cm, indicating good function. The functional outcome score was significantly related to the quality of articular reduction (P < 0.017, R = 0.456).

CONCLUSIONS: Posterior shearing tibial plateau fractures form a consistent pattern. They can be successfully managed using a posterior approach with direct reduction and buttress fixation of articular fragments. Quality of articular reduction is one factor that influences short-term functional outcome.