Five Years On and Still in Motion: A Retrospective Analysis of the Five-Year Survivorship of Dual Mobility Total Hip Arthroplasty Performed for Diverse Indications.

Background One of the most common causes of total hip Arthroplasty (THA) failures is instability and dislocation of the implant. Dual Mobility (DM) Liners were developed to help mitigate this risk. Aim of the study This study aims to study the functional at subjective results of Dual mobility THA performed for various purposes at a tertiary centre hospital in Mumbai, with a minimum post-operative period of five years. Methodology The study was conducted as a retrospective study in a tertiary health care hospital in a metropolitan city over a period of one year. Patients were examined clinically, and questions were asked to calculate the Harris hip score and Oxford hip score. Fresh plain radiographs were taken and evaluated. The mid-term post-operative results were analysed. We recruited 60 participants with a mean age of 65.77 years with SD 10.13, and the age range was between 35-88; and 53.3% of them (n = 28) were female. Results The range of post-operative period at the time of participant recruitment was 5-8 years, with a mean of 6.15 ± 0.77. Out of the total 60 patients, we observed complications in only four patients, which included persistent thigh pain in the post-op period (n=2), heterotrophic calcification in the post-op period (n=1), and revision THR at six years post-operatively (n=1). We also observed that only one participant developed aseptic loosening of the hip postoperatively. The clinical outcomes and observed the mean Harris' hip score to be 87.38 ± 4.41 in our population, and the mean Oxford hip score in our population was 37.35 ± 4.60.  The observed mean score for Moore's criteria for osteointegration was 3.10 ± 0.47. Most of the participants reported their post-operative condition to be excellent (60%), while 22% reported it to be good and 10% reported it to be fair. Implications A statistically significant association between the clinical outcomes and the subjective outcomes, indicating that participants who had better Harris' Hip scores and Oxford hip scores were more likely to subjectively feel their post-operative condition to be better. A statistically significant association between the radiological outcomes and the subjective outcomes, indicating that participants who had better Moore's criteria for osteointegration were more likely to subjectively feel their post-operative condition to be better. No statistically significant association between age and the Harris hip score and Oxford hip scores, indicating that the clinical outcomes were similar across all age groups. However, we observed a statistically significant difference between age and Moore's criteria for osteointegration, indicating that the radiological outcomes were worse with advancing age.