No Difference in Dislocation Rates Comparing Large Diameter Jumbo Femoral Heads and Dual-Mobility Bearings in Revision Total Hip Arthroplasty.

Background: Dual-mobility (DM) bearings reduce instability in revision total hip arthroplasty (THA); however, DM bearings are costly and reports of corrosion have recently emerged. Furthermore, no study has compared DM to standard bearings with large diameter femoral heads ≥40-mm. This study's purpose was to compare postoperative dislocation rates of standard and DM bearings with large femoral heads after revision THA.

Methods: A retrospective review of 301 consecutive revision THAs was performed. The mean follow-up was 37.1 months. To isolate the effect of the double articulation, standard and DM bearings with femoral heads ≥40-mm were compared. Outcomes were postoperative dislocation and reoperation within 90 days.

Results: The cohort consisted of 182 standard bearings and 75 DM bearings. There were no differences in revision indication comparing standard and DM bearings (P = .258). Overall dislocation rate was 8.6% (22 of 257). The dislocation rate was 5.7% for standard bearings with ≥40-mm femoral heads compared with 6.9% in DM bearings with ≥40-mm femoral heads (P = 1.000). In multivariate analysis, lower body mass index (odds ratio 1.72), female sex (odds ratio 2.01), and decreased outer femoral head diameter-to-cup component size ratio (odds ratio 1.64) were predictors of postoperative dislocation regardless of bearing type.

Conclusion: This study showed no difference in dislocation rates between standard and DM bearings when comparing similar femoral head diameters of ≥40-mm used in revision THAs. Considering the cost and potential deleterious issues associated with additional interfaces, DM bearings should be used judiciously considering similar results may be achieved with single-articulation bearings using large femoral heads.

Level Of Evidence: Level III.