Age matters when comparing hemiarthroplasty and total hip arthroplasty for femoral neck fractures in Medicare patients

Introduction: The optimal treatment of patients with a displaced intracapsular femoral neck fracture remains controversial. We utilised a national database of Medicare patients to determine if there was any difference in complications and reoperation rate of patients undergoing total hip arthroplasty (THA) or hemiarthroplasty (HA) for femoral neck fractures. Methods: This study utilised the PearlDiver Patient Records Database, a national for-fee database of Medicare patient procedure and diagnosis records from 2005 to 2012. Outcome procedures and diagnoses including revision, dislocation, infection, and cardiovascular events that occurred during the study time period were also identified over the entire study period as well as 90 days and 2 years. Results: We identified 275,439 patients with femoral neck fractures who underwent HA and 26,017 patients who underwent THA, respectively. Patients undergoing HA had significantly lower rates (p < 0.0001) of revision 2.48% versus 3.85% (OR = 0.633; 95% CI, 0.592-0.678), dislocation 1.76% versus 3.39% (0.512; 0.476-0.551), infection 3.44% versus 4.87% (0.694; 0.657-0.737). There was no statistical significant difference in 2-year cardiac morbidity (p = 0.252). However, when controlling for age, patients 65-69 years showed no significant difference in infection or revision over the study period or at 2 years. Conclusions: In this study, patients who underwent THA for femoral neck fractures had a higher rate of dislocations, infections and increased rates of repeat surgery than those who underwent HA but this difference was not significant in patients 65-69 years. Hemiarthroplasty may result in fewer complications in older Medicare patients although this difference may not be present in younger Medicare patients.