Rasmus Kreipke1, Cecilia Rogmark2,3, Alma B Pedersen4,5, Johan Kärrholm3,6, Geir Hallan7, Leif Ivar Havelin8, Keijo Mäkelä9, Søren Overgaard1,5. 1. Department of Orthopaedic Surgery and Traumatology, Odense University Hospital, and Department of Clinical Research, Faculty of Health Sciences, University of Southern Denmark, Odense, Denmark. 2. Department of Orthopaedics, Skåne University Hospital, Lund University, Malmö, Sweden. 3. Swedish Hip Arthroplasty Register, Gothenburg, Sweden. 4. Department of Clinical Epidemiology, Aarhus University Hospital, Aarhus, Denmark. 5. Danish Hip Arthroplasty Register, Aarhus, Denmark. 6. Department of Orthopaedics, Sahlgrenska University Hospital, Gothenburg, Sweden. 7. Norwegian Arthroplasty Register and Department of Orthopaedic Surgery, Haukeland University Hospital, Bergen, Norway. 8. Department of Clinical Medicine, University of Bergen, Bergen, Norway. 9. Department of Orthopedics and Traumatology, Turku University Hospital, Turku, Finland.
Abstract
BACKGROUND: The dual mobility acetabular cup (DMC) was designed to reduce prosthetic instability and has gained popularity for both primary and revision total hip arthroplasty (THA). We compared the risk of revision of primary THA for primary osteoarthritis between patients treated with a DMC and those who received a metal-on-polyethylene (MoP) or ceramic-on-polyethylene (CoP) bearing. METHODS: A search of the Nordic Arthroplasty Register Association (NARA) database identified THAs performed with a DMC during 1995 to 2013. With use of propensity score matching, 2,277 of these patients were matched (1:1), with regard to sex, age, component fixation, and year of surgery, with patients with an MoP or CoP bearing. We estimated the cumulative incidence of revision taking death as a competing risk into consideration and performed competing risk regression with revision or death as end points. RESULTS: There was no difference in the overall risk of revision between the DMC group and the propensity-score-matched MoP/CoP group (adjusted hazard ratio [HR] = 1.18; 95% confidence interval [95% CI] = 0.87 to 1.62). Patients with a DMC bearing had a lower risk of revision due to dislocation (adjusted HR = 0.09; 95% CI = 0.03 to 0.29) but a higher risk of revision caused by infection (adjusted HR = 3.20; 95% CI = 1.49 to 6.85). CONCLUSIONS: There was no difference in overall risk of revision between the DMC and MoP/CoP groups. The DMCs protected against revision due to dislocation but THAs performed with this bearing were more commonly revised because of infection. There may have been a selection bias toward placing DMC implants in patients with greater frailty as the mortality rates were higher in the DMC group than in the age and sex-matched MoP/CoP group. LEVEL OF EVIDENCE: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.
BACKGROUND: The dual mobility acetabular cup (DMC) was designed to reduce prosthetic instability and has gained popularity for both primary and revision total hip arthroplasty (THA). We compared the risk of revision of primary THA for primary osteoarthritis between patients treated with a DMC and those who received a metal-on-polyethylene (MoP) or ceramic-on-polyethylene (CoP) bearing. METHODS: A search of the Nordic Arthroplasty Register Association (NARA) database identified THAs performed with a DMC during 1995 to 2013. With use of propensity score matching, 2,277 of these patients were matched (1:1), with regard to sex, age, component fixation, and year of surgery, with patients with an MoP or CoP bearing. We estimated the cumulative incidence of revision taking death as a competing risk into consideration and performed competing risk regression with revision or death as end points. RESULTS: There was no difference in the overall risk of revision between the DMC group and the propensity-score-matched MoP/CoP group (adjusted hazard ratio [HR] = 1.18; 95% confidence interval [95% CI] = 0.87 to 1.62). Patients with a DMC bearing had a lower risk of revision due to dislocation (adjusted HR = 0.09; 95% CI = 0.03 to 0.29) but a higher risk of revision caused by infection (adjusted HR = 3.20; 95% CI = 1.49 to 6.85). CONCLUSIONS: There was no difference in overall risk of revision between the DMC and MoP/CoP groups. The DMCs protected against revision due to dislocation but THAs performed with this bearing were more commonly revised because of infection. There may have been a selection bias toward placing DMC implants in patients with greater frailty as the mortality rates were higher in the DMC group than in the age and sex-matched MoP/CoP group. LEVEL OF EVIDENCE: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.
Authors: John E Farey; James Masters; Alana R Cuthbert; Pernille Iversen; Liza N van Steenbergen; Heather A Prentice; Sam Adie; Adrian Sayers; Michael R Whitehouse; Elizabeth W Paxton; Matthew L Costa; Søren Overgaard; Cecilia Rogmark; Ola Rolfson; Ian A Harris Journal: Clin Orthop Relat Res Date: 2022-06-16 Impact factor: 4.755
Authors: Wayne Hoskins; Sophia Rainbird; Chelsea Dyer; Stephen E Graves; Roger Bingham Journal: Clin Orthop Relat Res Date: 2022-01-03 Impact factor: 4.755