Dual-mobility constructs or large femoral head bearings in revision total hip arthroplasty?

Dislocation remains a leading cause of failure following revision total hip arthroplasty (rTHA). Dual-mobility cups (DMCs) and large femoral heads (LFHs) have been employed to mitigate this risk, yet the comparative effectiveness remains debated. This systematic literature review aimed to compare dislocation, re-revision, and complication rates between DMC and LFH constructs in rTHA. This review followed PRISMA guidelines. A systematic search of Scopus, PubMed, and Embase databases yielded 2970 records. After screening using Covidence and removal of duplicates, 35 full texts were reviewed, and 9 studies met the inclusion criteria. Studies included patients undergoing rTHA with either DMC or LFH constructs and reporting on dislocation, re-revision, or related complications. Relative risk (RR), absolute risk reduction (ARR), and number needed to treat (NNT) for outcomes of interest were calculated. Nine comparative studies encompassing 3095 rTHAs (1204 DMCs and 1891 LFHs ≥36 ​mm) met the inclusion criteria. Post-operative dislocation occurred in 17 of 437 DMC hips (3.9%) and 54 of 711 LFH hips (7.6%), yielding a RR of 0.51 (49% reduction when DMC is used) and an ARR of 3.7% (NNT 27). Re-revision for any cause was also lower with DMCs (6.3% vs. 9.2%; ARR 2.9%), driven mainly by fewer re-revisions for instability (3.1% vs. 6.2%; ARR 3.1%). In rTHA, DMCs offer a potential reduction in dislocation and re-revision risk compared with LFHs, particularly in high-risk patients. While cost-effectiveness and survivorship analyses support DMC use, well-powered randomized controlled trials with long-term data are warranted. • Systematic review of nine comparative studies on revision total hip arthroplasty (rTHA). • Dual-mobility cups (DMCs) reduced rTHA dislocation versus large femoral heads (3.9% vs. 7.6%; RR 0.51). • All-cause re-revision was lower with DMCs (6.3% vs. 9.2%; ARR 2.9%; NNT 35). • Fewer instability re-revisions with DMCs (3.1% vs. 6.2%; ARR 3.1%; NNT 33). • No signal for infection or fracture; cost-effectiveness data are still lacking.