Dual-mobility bearings: a review of the literature

Dislocation after total hip arthroplasty remains a major problem and hip instability is the most common reason for revision. These complications are costly to both patients and the healthcare system, and efforts to reduce them have had varied degrees of success. Although there are well documented patient and surgical risk factors for dislocation, the typical surgical solutions offered (constrained liners, large femoral heads) have the drawbacks of reduced range-of-motion and high rates of revision. Dual-mobility prostheses (unconstrained tripolar prostheses) are hip design solutions to dislocation that aim to provide a greater stability with an increased range-of-motion, along with potentially reduced wear. The mean overall dislocation rate from multiple combined studies using dual-mobility prostheses was 0.1% for primary total hip arthroplasty and 3.5% for revisions, compared with 2-7% for standard primary total hip arthroplasties and up to 16% for revisions. Dual-mobility prostheses offer a viable option for treating recurrent dislocation as well as for primary and revision arthroplasty.