Low Rate of Dislocation of Dual-mobility Cups in Primary Total Hip Arthroplasty

Abstract

Background Dual-mobility (DM) cups were introduced to minimize the risk of THA dislocation. The overall rate of dislocation of DM cups (including both large and small articulations) is controversial and ranges from 0% to 5% in previous studies. Questions/purposes We therefore recorded (1) the dislocation rate, (2) loosening and osteolysis, and (3) subsequent related revisions with DM cups. Methods Between 1998 and 2003, 2480 primary THAs with DM cups were undertaken in 2179 patients. The mean age was 69 years (range, 19-94 years). This group underwent specific clinical and radiographic evaluation at a minimum followup of 0.17 years (mean, 7 years; range, 0.17-11 years) to assess dislocation, reoperation, osteolysis, and cup fixation.Results There were 22 dislocations (0.88%): 15 dislocations of large articulations (0.6%), with two (0.08%) recurring but only one requiring revision (0.04%), and seven intraprosthetic small articulation dislocations (0.28%), all needing revision surgery. At last followup, mean Harris hip score was 91 (range, 60-100); 2439 cups (98%) showed no signs of loosening; and 141 patients (145 hips) had osteolysis (6%). Osteolysis and cup loosening were more frequent in patients younger than 50 years at the time of surgery. The 10-year survivorship considering revision for any reason was 93% (95% CI, 91%-95%). Conclusions DM cups had a low dislocation rate in primary THA, with a limited frequency of adverse effects. We recommend DM cups to minimize dislocation in populations at high risk for instability, but they should be avoided in younger, active patients at higher risk for osteolysis.

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

“…Similarly, Combes at al. investigated 2480 primary THA with DMCs and reported 0.88% dislocation rate, which is far below the rates reported with conventional THA [14]. Similar results were observed in our current register study, where revision rates due to dislocation in DMCs were 0.7% compared with 2.4% in the Exeter group.…”

“…A p value < 0.05 was considered significant. In the case of bilaterally operations, both hips were included, but it has been reported that this has little effect on survival in register studies [14].…”

Outcomes of dual mobility cups in a young Middle Eastern population and its influence on life style

“…Dual mobility cups (DMC) were designed as a solution to reduce THA dislocation events [9,10]; the mobile polyethylene insert would diminish the occurrence of prosthetic neck impingement with the fixed cup and the large diameter articulation between the poly-ethylene component and the metallic acetabular component would increase the range of motion before dislocation [11,12]. Some complications were reported after the use of the first generation cups due to the premature wear of the polyethylene (intra-prosthetic dislocation), insufficient means of bony fixation and iliopsoas tendon impingement [13,14].…”

Dual-mobility or Constrained Liners Are More Effective Than Preoperative Bariatric Surgery in Prevention of THA Dislocation

“…Dual-mobility acetabular cups [7,12,13,34] or constrained cups [17] can decrease the risk of dislocation and may be indicated in some patients whose risk of this complication is increased. However, studies up to now have not specifically analyzed the benefit of using these implants in patients with obesity as compared with standard implants in patients with obesity.…”