Dual mobility cup in revision total hip arthroplasty: Dislocation rate and survival after 5 years

• Published in: Orthopaedics & traumatology, surgery & research surgery & research, 2015-09, Vol.101 (5), p.577-581
• Main Authors: Simian, E, Chatellard, R, Druon, J, Berhouet, J, Rosset, P
• Format: Article
• Language: English
• Subjects: Adult; Aged; Aged, 80 and over; Arthroplasty, Replacement, Hip; Dislocation rate; Dual mobility cup; Female; Follow-Up Studies; Hip Prosthesis - adverse effects; Humans; Male; Middle Aged; Orthopedics; Prosthesis Design; Prosthesis Failure; Reoperation; Retrospective Studies; Surgery; Survivorship; Total hip replacement; Total hip revision
• ISSN: 1877-0568; 1877-0568
• DOI: 10.1016/j.otsr.2015.05.002

Abstract Background Dislocation is a common complication of total hip arthroplasty (THA), particularly when performed as revision surgery. Dual mobility cups (DMCs) minimize the risk of instability when implanted during primary THA. However, their usefulness and survival in revision THA remain unclear. We therefore conducted a retrospective study to assess DMC stability and survival at a minimal follow-up period of 5 years after revision THA. Hypothesis The dislocation rate associated with DMCs for revision THA is similar to that seen after primary THA. Materials and methods Cup exchange with implantation of a DMC was performed in 71 patients (74 hips) between 2000 and 2007, for the following reasons: recurrent dislocation ( n = 22), aseptic loosening ( n = 38), and infection ( n = 14). The DMCs were cemented in 47 cases and cementless in 27 cases. The clinical variables (Merle d’Aubigné-Postel score and Harris Hip Score) and radiological findings were collected retrospectively from the medical records and compared with those obtained at the last follow-up visit. Results Of the 74 cases, 2 were lost to follow-up. At last follow-up, the mean Merle d’Aubigné-Postel score was 15.2 (11–18) and the mean Harris Hip Score was 80.4 (51–98). Of the 8 failures, 2 (2/72, 2.7%) were related to mechanical factors (1 case each of aseptic loosening and dislocation) and 6 were changed because of infection (recurrent infection, n = 4). Mechanical failure was not linked to a specific reason for revision THA. A radiolucent line was visible in 4 cases but this finding was not associated with clinical manifestations. When failure was defined as cup revision for any non-infectious complication, 5-year implant survival was 99% (95% confidence interval, 93–100%). Discussion Use of a DMC in revision THA was associated with a slightly higher dislocation rate (1/72, 1.4%) than in primary THA, whereas 5-year survival was comparable. Cemented DMCs were not associated with a greater risk of loosening. Conclusion DMCs are useful to decrease the risk of dislocation in revision THA performed for any reason. The low rate of loosening indicates that DMCs do not result in high stresses at the bone-implant interface. Level of evidence IV, retrospective study.