Short-term outcome after total hip arthroplasty using dual-mobility cup: report from Lithuanian Arthroplasty Register

Abstract

PURPOSE: The purpose of the study was to investigate how the use of dual-mobility cups (DMCs) affected the risk of revision due to dislocation as well as overall risk of revision compared with a conventional total hip arthroplasty (THA) system in the short term. METHODS: A total of 12,657 primary THAs were registered from the start of 2011 to the end of 2014. 620 THAs were with DMCs. For comparison, we included all registered THAs with Exeter cup and a cemented Exeter stem combined with 28-mm femoral head. Patients were followed up with respect to revision and/or death until 1 January 2016. For survival analysis, we used revision as an endpoint. Cox proportional hazards models were used to analyse the influence of various covariates (age, gender, surgical approach, THA model and pre-operative diagnosis). RESULTS: Of the 620 dual-mobility THAs and 2170 Exeter THAs, 100 had been revised. The overall unadjusted cumulative revision rate (CRR) for any reason of revision at five years after surgery was 3.9% in the dual-mobility group and 5.2% in the Exeter group. Cox regression analysis, adjusting for age, gender, THA type, surgical approach and pre-operative diagnosis, showed that the risk of revision was less in patients operated with DMCs and in patients having their operation for osteoarthritis. CONCLUSION: The DM implant had a lower short-term complication rate than a conventional well defined THA. Low dislocation rate suggests that it is a good choice for high risk patients.