Postoperative weightbearing timing after distal femur osteotomy is not associated with rates of union or complications: A systematic review and meta-analysis

To assess the outcomes and complication rates of early weightbearing (either immediate weightbearing as tolerated or partial weightbearing) and delayed weightbearing (an initial period of non-weightbearing or toe-touch weightbearing) following distal femoral osteotomy (DFO). A systematic literature search using PubMed, Embase and Cochrane Reviews was performed. Inclusion criteria were studies reporting on outcomes and complications after DFO with a minimum 1-year follow-up. Methodologic quality of studies was assessed using the methodological index for non-randomised studies (MINORS) criteria. Data collection included incidence of nonunion, delayed union, loss of fixation or deformity correction, knee stiffness, venous thromboembolism (VTE) and patient-reported outcome measures (PROMs). Meta-analysis was performed utilising random effects models, with statistically significant results denoted by a p-value <&#x2009;0.05. Twenty-six studies (23 level IV and 3 level III) with 814 patients were included (mean age 42 years, mean follow-up 5.2 years). All but one study (25/26 [96.2%]) had moderate quality methodology. Statistical comparison was limited by low event frequency, and thus no statistically significant associations were identified, and p-values were omitted. The overall complication rates were nonunion 2.5% (95% confidence interval [CI] 1.6%-3.8%), delayed union 0.6% (95% CI 0.1%-3.3%), loss of fixation or deformity correction 1.4% (95% CI 0.5%-3.5%), knee stiffness 2.9% (95% CI 1.4%-6.1%), VTE 0.9% (95% CI 0.3%-2.3%). Validated PROMs were reported in 11 of 26 studies (42%) using heterogeneous instruments, precluding quantitative pooling and meta-analysis. There were relatively low overall mean rates of delayed union, nonunion, loss of fixation or deformity correction, and VTE after DFO, regardless of an early or delayed post-operative weightbearing protocol. Due to limited comparative data and the risk of selection bias, definitive conclusions cannot be drawn regarding the safety of early weightbearing after DFO, underscoring the need for prospective controlled studies. Level IV.