Cementation of a Metal Dual Mobility Liner in Patients Undergoing Revision Total Hip Arthroplasty.

Background: Dual mobility liners for primary and revision total hip arthroplasties can lead to decreased dislocation and revision rates. However, there are a lack of data analyzing their utilization when cementing into well-fixed acetabular components in a variety of scenarios. Therefore, the purpose of this study was to examine cementation of dual mobility liners into well-fixed existing acetabular components from previous hip procedures, into new acetabular components, or directly into the acetabulum without prior implants. We specifically aimed to assess the following: (1) aseptic revision-free implant survivorship, (2) patient-reported outcomes, (3) prosthetic joint infections, dislocations, and osteolysis, (4) medical complications and readmissions, and (5) radiographic outcomes. Methods: A total of 35 patients who underwent treatment with a cemented dual mobility liner from October 1, 2014, to July 1, 2018, were identified and followed up for a mean of 4 years (range, 4-8). The primary outcome of interest was revision-free survival. The secondary outcomes included patient-reported outcome measurements, dislocations, periprosthetic infections, periprosthetic fractures, pulmonary emboli, deep vein thromboses, radiographic osteolysis, and emergency visits as well as inpatient admissions. The patient-reported outcome measurements used were the Hip Disability and Osteoarthritis Outcome Score for Joint Replacement, Short-Form 12 Health Survey Mental Component, and Short-Form 12 Health Survey Physical Component. Results: Aseptic revision-free survivorship was 93.3%, 92.3%, and 100% for previous acetabular cup, new cup, and native acetabulum, respectively. The Hip Disability and Osteoarthritis Outcome Score for Joint Replacement improved and the Short-Form 12 Physical Component improved postoperatively for all groups. Surgical complications included 3 prosthetic joint infections (1 in a new cup and 2 in native acetabula). A total of 1 patient (previous cup) had an emergency visit and inpatient readmission. Only 1 cemented dual mobility recipient (new cup) demonstrated progressive acetabular radiolucencies and all cemented dual mobility patients had no evidence of acetabular subsidence. Conclusions: Cemented dual mobility bearing liners demonstrated exceptional survivorship, low complication rates, adequate radiographic results, and improved functional outcomes when cemented into previously inserted well-fixed acetabular components, new components, or native acetabula. To the best of the authors' knowledge, this is the first study to demonstrate success at a minimum of 4-year follow-up. These data are important to surgeons deciding on the appropriate implantation methods to use for their high-risk patients.