Clinical outcomes and complications of a non-modular dual-mobility acetabular device, minimum 2 years follow-up

Non-modular dual-mobility (DM) acetabular bearing constructs are becoming more popular due to their potential advantages for addressing range of motion (ROM) and stability. The objective of this post-market clinical study was to assess clinical outcomes, including patient satisfaction, pain and function, survivorship, and component positioning, in patients ⩾2 years after primary THA using non-modular DM acetabular components.

This retrospective, multicentre study evaluated complications and functional outcomes in recipients of non-modular DM acetabular constructs at least 2 years post-THA. Our primary outcomes included the dislocation rate and mean Hip disability and Osteoarthritis Outcomes Score (HOOS). Secondary outcomes included radiographic measurements, patient satisfaction, Forgotten Joint Score (FJS), Harris Hip Score (HHS), and survivorship.

316 eligible patients enrolled in this study across 3 sites, including 168 men (53%) and 148 women (47%). The cohort averaged 5.37 years post-THA (range 2.2-10.1 years) at the study visit. The mean FJS, HHS, and HOOS were good to excellent, with values of 82.3, 90.7, and 92.0, respectively. Patient satisfaction averaged 4.68, between "Very Good" (4) and "Excellent" (5). Minimal radiolucent lines (RLL) surrounded the acetabulum. More RLL surrounded the femur, but most lines were less than 1 mm (4.7% of the study population). There were few adverse events (4 events, 1.3%). Three revisions were performed (0.9%), with one patient requiring removal of the acetabular cup.

The high mid- to long-term survivorship and low to no dislocation and reoperation rates indicate this acetabular DM device is a viable option for THA patients. The patient metrics reflect satisfaction, alleviated pain, and restored function with a low risk of adverse outcomes.