Cemented dual-mobility total hip arthroplasty cups in a custom-made acetabulum: a clinical and radiological evaluation

Background : Acetabular reconstruction during revision total hip arthroplasty (THA) with major bone loss is a complex surgical challenge. The combination of custom-made (CM) acetabular components with cemented dual mobility (DM) cups may improve postoperative outcomes in this context. This study aims to assess the clinical, functional, and radiological results of this surgical approach. Methods : We conducted a retrospective, single-center observational study including 16 patients (mean age 70 years) who underwent revision THA between May 2016 and December 2024 using a cemented DM cup in a CM acetabular component. All patients presented with Paprosky 3A or 3B defects, and 38% had a history of periprosthetic joint infection (PJI). Functional outcomes were measured using the Oxford Hip Score (OHS) and modified Harris Hip Score (mHHS) pre- and postoperatively. Radiographic assessment included measurement of the center of rotation (COR) deviation in both axes, as well as acetabular inclination and anteversion on postoperative CT scans. Implant survival was analyzed using Kaplan-Meier methodology. Results : At a mean follow-up of 16.2 months, overall implant survival was 75%, increasing to 93.8% when excluding isolated DM cup revisions. No postoperative infections were observed. OHS improved from 14.1 to 27.6 and mHHS from 27.4 to 52.7 ( p < 0.001 for both). A significant negative correlation was observed between vertical ( y -axis) COR deviation and functional scores ( p < 0.01), highlighting the importance of restoring vertical COR. Mean inclination and anteversion were 41.2° and 29°, respectively, generally within target alignment zones. Discussion : The combination of cemented DM cups with CM acetabular components appears to be an effective technique in complex revision THA. Functional recovery and implant survivorship are consistent with the existing literature, and the absence of infection despite prior PJI history suggests benefit from a multidisciplinary approach. Restoration of vertical COR is a predictor of functional outcomes.