Fracture characteristics and functional outcomes for Schatzker V/VI bicondylar tibial plateau fractures with a separate tubercle fragment: a comparative study

INTRODUCTION: A separate tibial tubercle fragment (TF) is found in up to half of all bicondylar tibial plateau (BTP) fractures. Adequate healing of the TF is required to reconstitute the extensor mechanism of the knee. The purpose of this study was to compare outcomes after surgical fixation of BTP fractures with and without a TF.

MATERIALS AND METHODS: Retrospective comparative study of adult patients undergoing open reduction internal fixation (ORIF) of a Schatzker V/VI BTP fracture at two Level 1 trauma centers. Primary outcomes were patient-reported outcomes as assessed by the PROMIS Physical Function (PF) score and EQ-5D-3L. Secondary outcomes included rates of infection, reoperation, and nonunion. Patient demographics, fracture characteristics, and outcomes were compared for patients with and without a TF.

RESULTS: 189 patients (mean follow-up 8.1 yrs) were included. 55 patients (29%) had a separate TF. There was no significant difference in PROMIS PF (48.1 vs 47.5, p = 0.45) or EQ-5D-3L scores (0.82 vs 0.83, p = 0.32) between patients with and without a separate tubercle fragment.Patients with a TF had more open fractures (16% vs 5%, p = 0.02) and high energy injuries (66% vs 49%, p = 0.03).There was no significant difference in the rates of deep infection (15% vs 8%, p = 0.19) or unplanned reoperation (23% vs 13%, p = 0.09). There were more nonunions in the TF group (11% vs 2%, p = 0.02) but only two involved the tubercle fragment.

CONCLUSION: In this comparative study, the presence of a TF did not portend a worse functional outcome for patients with a healed fracture. Rates of open fracture and high energy mechanism of injury were significantly higher in the TF group.. Surgeons should be aware that a separate TF may indicate a more severe injury. More studies are needed to determine whether the presence of a TF is associated with higher complication rates.