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A Comparison of Revision Rates for Dislocation and Aseptic Causes Between Dual Mobility and Large Femoral Head Bearings in Primary Total Hip Arthroplasty With Subanalysis by Acetabular Component Size: an Analysis of 106,163 Primary Total Hip Arthroplasties

Author

J Arthroplasty. 2021 May 11;S0883-5403(21)00422-8. doi: 10.1016/j.arth.2021.05.008.Online ahead of print.

Wayne Hoskins 1Roger Bingham 2Chelsea Dyer 3Sophia Rainbird 4Stephen E Graves 5

Author Information

1 Faculty of Medicine, Dentistry and Health Sciences, The University of Melbourne, Parkville, Victoria, Australia; Traumaplasty.Melbourne, East Melbourne, Victoria, Australia.

2 Traumaplasty.Melbourne, East Melbourne, Victoria, Australia; Department of Orthopaedics, Royal Melbourne Hospital, Parkville, Victoria, Australia.

3 South Australian Health and Medical Research Institute (SAHMRI), Adelaide, South Australia, Australia.

4 Australian Orthopaedic Association National Joint Replacement Registry (AOANJRR), Adelaide, South Australia, Australia.

5 Australian Orthopaedic Association National Joint Replacement Registry (AOANJRR), Adelaide, South Australia, Australia; Clinical and Health Sciences, University of South Australia, Adelaide, South Australia, Australia.

Abstract

Background: Dual mobility (DM) and large femoral head bearings (≥36 mm) both decrease the risk of dislocation in total hip arthroplasty (THA). There is limited comparable data in primary THA. This study compared the revision rates for dislocation and aseptic causes between DM and large femoral heads and subanalyzed by acetabular component size.

Methods: Data from the Australian Orthopedic Association National Joint Replacement Registry were analyzed for patients undergoing primary THA for osteoarthritis from January 2008 (the year of first recorded DM use) to December 2019. All DM and large femoral head bearings were identified. The primary outcome measure was the cumulative percent revision (CPR) for dislocation and for all aseptic causes. The results were adjusted by age, sex, and femoral fixation. A subanalysis was performed stratifying acetabular component diameter <58 m and ≥58 mm.

Results: There were 4942 DM and 101,221 large femoral head bearings recorded. There was no difference in the CPR for dislocation (HR = 0.69 (95% CI 0.42, 1.13), P = .138) or aseptic causes (HR = 0.91 (95% CI 0.70, 1.18), P = .457). When stratified by acetabular component size, DM reduced the CPR for dislocation in acetabular component diameter <58 mm (HR = 0.55 (95% CI 0.30, 1.00), P = .049). There was no difference for diameter ≥58 mm. There was no difference in aseptic revision when stratified by acetabular component diameter.

Conclusion: There is no difference in revision rates for dislocation or aseptic causes between DM and large femoral heads in primary THA. When stratified by acetabular component size, DM reduces dislocation for acetabular component diameter <58 mm.

Level of evidence: Level III.