OBJECTIVES: Femoral neck fracture (FNF) is the most common type of hip fracture accounting for more than 50% of hip fractures. Approximately 70% of FNFs are categorized as displaced and require surgery, typically with total hip arthroplasty (THA). For the foreseeable future in Asia, the number of hip fractures (2018: 1.12MM, 2050: 2.56MM) and associated costs (2018: $9.5B USD, 2050: $15B USD) are expected to grow substantially. Currently, there are no systematic reviews published comparing differences between hemiarthroplasty (HA) and dual-mobility THA for the treatment of displaced FNFs.

METHODS: A meta-analysis was conducted, including randomized controlled trials and cohort studies, to examine the difference between HA and dual-mobility THA on clinical outcomes after hip arthroplasty for displaced FNFs. Full papers identified through a systematic search of MEDLINE, EMBASE, and Cochrane Controlled Trials databases were eligible. Risk ratios for dislocation and the weighted mean differences for Harris Hip Score (HHS) were calculated. Fixed-effect (Mantel-Haenszel) models were employed. Stata 15.1 (StataCorp LLC, College Station, TX, USA) was used for statistical analysis.

RESULTS: In total, six cohort studies including 983 patients were identified. After a mean follow-up of 2.0 (range, 1.4 – 3.0) years, there was significantly lower likelihood of dislocation for dual-mobility THA compared with HA (risk ratio, 0.34 [95% CI, 0.20 to 0.59], p < 0.001). Two studies reported postoperative HHS in 231 patients. The weighted mean difference in HHS was 4.1 points (95% CI, 1.7 – 6.5 points, p < 0.001) in favor of the dual-mobility THA group.

CONCLUSIONS: This meta-analysis of comparative studies revealed that dual-mobility THA is associated with a lower rate of dislocation and a higher HHS score compared with HA in patients with displaced FNFs. Technologies which reduce the incidence of hip dislocation and improve patient outcomes will offer demonstrable economic value to patients, healthcare providers, and payers.