Preoperative posterior tilt can be a risk factor of fixation failure in nondisplaced femoral neck fracture: a systematic review and meta-analysis

PurposeThis systematic review and meta-analysis aimed to identify whether posterior tilt increases the risk of treatment failure in nondisplaced femoral neck fractures.MethodsWe searched the databases of the PubMed, Embase, and Cochrane Library from 1980 to 2022. The search strategy was based on the combination of keywords "nondisplaced," "hip fracture," "femoral neck fracture," and "internal fixation." Cohort studies enrolled patients with nondisplaced (Garden I and Garden II) femoral neck fractures were included. Two investigators independently extracted data and the other two assessed the methodological quality. Data were analyzed using Review Manager software.ResultsWe analyzed 13 cohort trials with a pooled sample of 4818 patients, with posterior tilt >= 20 degrees in 698 patients and < 20 degrees in 3578 patients in 11 trials, and posterior tilt >= 10 degrees in 483 patients and < 10 degrees in 496 patients in 4 trials. All studies were of high quality based on Newcastle-Ottawa Scale evaluation. Treatment failure was reported in 24.4% (170/698) of patients with posterior tilt >= 20 degrees and 10.9% (392/3578) of patients with posterior tilt < 20 degrees, indicating that posterior tilt >= 20 degrees was significantly associated with a higher risk of treatment failure (Risk ratio, 2.73; 95% confidence interval [CI], 1.77-4.21). Posterior tilt >= 10 degrees was not found to be a risk factor for fixation failure (risk ratio, 1.92; 95% CI 0.76-4.83).ConclusionNondisplaced femoral neck fractures with posterior tilt >= 20 degrees were associated with an increasing rate of failure when treated with internal fixation.