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.