Tibial tuberosity ossification predicts reoperation for growth disturbance in distal femoral physeal fractures

PURPOSE: Distal femoral physeal fractures (DFPF) can cause growth disturbance that requires further surgical intervention. The aim of this study is to determine if Tibial Tuberosity Ossification Stage (TTOS) at the time of injury predicts secondary surgery for growth disturbance in patients who have sustained a DFPF. METHODS: We retrospectively investigated all patients who had operative treatment for a DFPF at a single centre over a 17-year period. Regression analysis was performed investigating associations between secondary surgery to treat growth disturbance and TTOS, age, Salter-Harris fracture classification type, mode of fixation or mechanism of injury. RESULTS: In all, 85 consecutive patients were identified. A total of 74 met the inclusion criteria. The mean age at time of injury was 13.1 years (2.0 to 17.1). Following fixation, 30 patients (41%) underwent further surgery to treat growth disturbance. Absence of tibial tuberosity fusion to the metaphysis was significantly associated with the need for further surgery (p < 0.001). Odds of requiring secondary surgery after tibial tuberosity fusion to metaphysis (compared with not fused) were 0.12 (95% confidence interval (CI) 0.04 to 0.34). The estimate of the effect of TTOS on reoperation rates did not vary when adjusted for gender, mechanism, fixation and Salter-Harris type. When accounting for age, the odds of any further operation if the tibial tuberosity is fused to the metaphysis (compared with not fused) were 0.28 (95% CI 0.08 to 0.94). CONCLUSION: TTOS at the time of injury is a predictor of further surgery to treat growth disturbance in paediatric distal femoral fractures. LEVEL OF EVIDENCE: Diagnostic Level II