The aim of this study was to evaluate outcomes of internal fixation for displaced femoral neck fracture (FNF) between 50 and 60 years old. The patient and surgical factors for the failure were identified.

We retrospectively reviewed the records of 102 displaced FNF patients between 50 and 60 years old (mean age 54.9 years) who had undergone internal fixation between 2005 and 2016. The minimum follow-up was 12 months. Primary end points included loss of reduction, non-union, and osteonecrosis of the femoral head (ONFH). Preoperative Pauwel’s angle, fixation timing and methods, reduction quality, removal of implant and medical comorbidities were analysed.

The overall failure rate was 44.1%. In multivariate logistic regression analysis, poor reduction quality (adjusted odds ratio [aOR] 4.38; 95% confidence interval [CI], 1.54–12.46) and internal fixation delayed more than 6 hours (aOR 3.24; 95% CI, 1.08–9.69) were risk factors for all causes of failure. In a stratified analysis, poor reduction quality (aOR 3.81; 95% CI, 1.11–13.04) and a history of alcohol dependency (aOR 4.91; 95% CI, 1.09–22.13) were risk factors for loss of reduction. Internal fixation delayed >6 hours (aOR 3.67; 95% CI, 1.05–12.77) and removal of implant (aOR 3.32; 95% CI, 1.02–10.77) were risk factors for ONFH.

The outcome of internal fixation of displaced FNF in patients between 50 and 60 years old is suboptimal. The patient selection is important. Non-alcohol dependency lowered early failure. Implant retention reduced ONFH. Surgery within 6 hours and good quality of reduction yield better results.