Total Hip Arthroplasty Versus Hemiarthroplasty for Displaced Femoral Neck Fracture A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Background: Hip fractures are a leading cause of disability worldwide, with displaced femoral neck fractures being of particular concern. A recent meta-analysis reported that total hip arthroplasty (THA) was superior to hemiarthroplasty (HA) in terms of reoperations, but inferior in terms of dislocations. However, publication of 4 additional randomized controlled trials that enrolled nearly 1,780 additional patients merits an updated meta-analysis. Methods: We conducted a literature search of 4 databases to identify randomized controlled trials comparing THA and HA in patients with displaced femoral neck fractures. For patient-reported outcomes, the minimally important difference informed calculation of risk differences. We performed a subgroup analysis to address the possible impact of risk of bias and performed meta-regression to assess the possible impact of duration of follow-up. Results: Sixteen studies that enrolled 3,084 patients randomized to undergo THA (n = 1,521) or HA (n = 1,563) proved eligible. There were no significant differences between the 2 groups in terms of the revision rate at up to 5 years of follow-up or functional outcome at up to 3 years. Health-related quality of life was superior in the THA group (mean difference [MD] = 0.05, 95% confidence interval [CI] = 0.02 to 0.07, minimally important difference, 0.145). There was no significant difference between the groups in terms of dislocation or periprosthetic fracture incidence. Operative time was significantly shorter in the HA group (MD = 22 minutes, 95% CI = 9 to 35 minutes). Analyses addressing risk of bias and length of follow-up did not reveal subgroup differences. Certainty of evidence for all outcomes was rated as moderate. Conclusions: The best evidence showed, with moderate certainty, that HA and THA likely result in similar revision rate, function, mortality, periprosthetic fracture, and dislocation at up to 5 years, with a small, possibly unimportant benefit in health-related quality of life with THA. More specifically, the improvements are well below established cutoffs for clinical importance. Almost half of all patients were from a single large randomized controlled trial, although the results were consistent across the studies. In addition, HA likely results in a clinically unimportant reduction in operative time.