TY - JOUR

T1 - Dual Mobility Cups

T2 - Effect on Risk of Revision of Primary Total Hip Arthroplasty Due to Osteoarthritis: A Matched Population-Based Study Using the Nordic Arthroplasty Register Association Database

AU - Kreipke, Rasmus

AU - Rogmark, Cecilia

AU - Pedersen, Alma B.

AU - Kärrholm, Johan

AU - Hallan, Geir

AU - Havelin, Leif Ivar

AU - Mäkelä, Keijo

AU - Overgaard, Søren

PY - 2019/1/16

Y1 - 2019/1/16

N2 - 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.

AB - 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.

U2 - 10.2106/JBJS.17.00841

DO - 10.2106/JBJS.17.00841

M3 - Journal article

C2 - 30653047

AN - SCOPUS:85060132931

VL - 101

SP - 169

EP - 176

JO - Journal of Bone and Joint Surgery - Series A

JF - Journal of Bone and Joint Surgery - Series A

SN - 0021-9355

IS - 2

ER -