Functional and Radiological Outcomes Following Simultaneous Bilateral Total Hip Arthroplasty: Analysis of a Retrospective Series

Introduction The prevalence of bilateral hip arthritis continues to rise. With the dramatic change in the practice of modern-day arthroplasty with standard operating protocols and guidelines in place to reduce the incidence of surgical site infection and peri-operative thromboembolic events, simultaneous bilateral total hip replacement (THR) has been considered a viable option to reduce morbidity. The efficacy of simultaneous bilateral THR with regard to patient outcomes and complications has been debated. The aim of this study was to assess and compare the functional outcomes, radiological outcomes, and complications following bilateral simultaneous THR with the existing literature. Methods We conducted a retrospective study of 28 patients who underwent simultaneous bilateral THR by a single surgeon at a district general hospital in the United Kingdom between 2010 and 2019. All the patients in the study were operated on via the posterior approach to the hip and received uncemented implants. Data on blood loss and hospital stay were collected from the hospital records. The radiological outcomes were studied from the post-operative radiographs. The patient-reported outcomes were measured via a telephone session at an average follow-up of 7.8 years. Results Our results noted a statistically significant drop in haemoglobin after the procedure from a mean of 13.5 g/dl to 9.05 g/dl (t: -15.84, p < 0.00001). The average blood loss was 643 ml +/- 330 ml (200-1850 ml). Nine patients (32.1%) required blood transfusions and a total of 21 units were transfused. The mean duration of stay in the hospital was 6.7 days (three to 20 days). There were no intra-operative/immediate/early post-operative complications. The revision rate was 1.7%, as one patient had a revision of the femoral component following a peri-prosthetic fracture. The mean visual analogue scale pain score was 1.51 +/- 0.58 (1-3). The mean Oxford Hip Score improved from 19.5 (12-28) pre-operatively to 44.3 (37-48) post-operatively at the time of the study (t: -21.88945; p < 0.00001), with the difference being statistically significant using a paired t-test. From the series, 14 (50%) patients were found to have limb length discrepancies. The mean limb length discrepancy was found to be 2.3 mm (0-16 mm). In 13 of the 28 patients (46.4%), the global hip offset was equal on both sides. In two patients, the difference in the global hip offset was more than 10 mm. Conclusion We reported good patient-reported functional outcomes with simultaneous bilateral THR with a low complication rate. Despite the lack of opportunity to template the second hip, the limb length and global hip offset can be restored after a simultaneous bilateral THR.