(P 283) HIP ARTHROPLASTY OUTCOMES IN METASTATIC BONE DISEASE

Objective: The hip is a common location for metastatic bone disease (MBD) and surgical intervention is often indicated to relieve pain and improve function. MBD of the hip is usually treated with hemiarthroplasty or total hip arthroplasty if there are lesions present in the acetabulum. In contrast to hip arthroplasty for osteoarthritis, there is limited data on outcomes of hip arthroplasty in patients with MBD. As treatment for metastatic disease evolves and patients may expect to live longer after diagnosis, further evaluation of the complications and functional outcomes associated with hip arthroplasty for MBD are necessary. The primary purpose of this investigation was to examine the rates of reoperation and other complications in patients undergoing hip arthroplasty for MBD. This study also examined perioperative mortality and postoperative functional outcomes in this patient population.

Methods: This was a retrospective review of patients who underwent hip arthroplasty for MBD at a single institution between 2007 and 2021. Patients who survived the perioperative period had a minimum follow-up of six months. Demographics, histopathologic diagnosis, surgical details, and outcomes including rates of reoperation and survival were collected. Descriptive statistics were used to describe patient demographic and clinical characteristics as well as outcome measures. Preoperative and postoperative function were scored on a four-point scale: bedridden (0), wheelchair-bound (1), ambulatory with an assistive device (2), or ambulatory without an assistive device (3). Student’s paired t-test was used to compare preoperative and postoperative functional scores.

Results: Ninety-three cases in 91 patients were included in the study. Total hip arthroplasty (THA) was performed in 52 cases (55.9%), hemiarthroplasty was performed in 15 (16.1%), and complex arthroplasty, including proximal femur replacement or THA with complex acetabular reconstruction, was performed in 26 (28%). There were 11 reoperations in five patients, two periprosthetic joint infections, and two postoperative periprosthetic fractures. Dislocations occurred in six patients, two treated with primary THA and four treated with complex arthroplasty. Median survival was 10.4 months, and one-year overall survival was 53.3%. In the 88 patients who survived to hospital discharge, 85 patients (96.6%) were able to ambulate independently or with an assistive device after surgery. There was also a significant increase in the proportion of patients who were able to ambulate independently (35.2% vs 17.6%; p=0.02) and a significant decrease in patients confined to a wheelchair (18.7% vs 3.3%; p=0.045) after surgery.

Conclusion: Hip arthroplasty for MBD leads to relatively low rates of complications and reoperations in this population known to have high postoperative morbidity and mortality. Hip arthroplasty provides the majority of MBD patients with a durable reconstruction that exceeds their lifespan and enables them to return to an acceptable level of function.