Acute femoral fracture does not compromise the outcome of total hip arthroplasty: 5 year results from a single center cohort study in 2,782 patients

National arthroplasty registries reveal a higher risk of revision for periprosthetic fracture and dislocation after total hip arthroplasty (THA) in patients with a femoral neck fracture compared to those with osteoarthritis (OA). Since these registries may contain confounding factors, we conducted a single center cohort study comparing survival and reason for failure between THA for an acute femoral neck fracture and OA using the same hip prosthesis after a minimum follow-up of 2 years. We retrospectively analyzed 2782 patients who had undergone THA with an Accolade TMZF stem and a Trident cup between March 2009 and September 2014. Primary diagnosis before THA was osteoarthritis (OA group: n=2610) or acute femoral fracture (Fracture group: n=172). Patients in both groups were operated on by the same hip surgeons. Effect of diagnosis on THA survival was analyzed using Cox-regression analysis. Chi-square tests were used to illustrate the different reasons for revision between the groups. Mean follow-up was 4.6 years (2-7.6). A total of 100 revisions were performed. The revision risk was comparable between the OA and Fracture group (HR=1.04, 95% CI:0.46-2.39). No differences were found between the OA and Fracture group with respect to the occurrence of periprosthetic fractures (0.8% vs. 0.6%, p=0.71) and revisions for dislocation (0.6% vs. 1.2%, p=0.38). We found no difference in outcome or reason for revision between THA for OA or femoral neck fracture. Using an implant with a proven ODEP rating and having experienced hip surgeons carry out the procedures may be more important than the primary diagnosis.