EPISODE-OF-CARE COSTS OF REVISION TOTAL HIP ARTHROPLASTY IN THE BMI > 45 PATIENT

As obesity becomes increasingly prevalent in north American societies and worldwide, both the need for hip arthroplasty and the subsequent complications are increasing. Of particular interest is the super-obese classification with BMI>45. These patients have increased costs of primary hip arthroplasty and increased risk of revision, relative to both the non-obese and the obese with a BMI < 4 5. Economic decisions about arthroplasty funding, in both private and public payer systems, can treat population averages and miss nuances that occur in specific subsets such as this superobese population. We performed a retrospective study of all revision arthroplasty done for morbid and super obese (BMI>45) patients between 2006-2022 in our institution. We considered all cause revisions in our analysis. We used a micro-costing approach to calculate 90-day costs for each surgery required and treated each revision as a separate 90-day period. Readmission and presentation to emerge during this time was also noted. Patients were excluded if the first revision in their series of revisions had a BMI below 45. Primary arthroplasty in population with BMI>45 were available for comparison from previous analysis by our group. We reviewed 62 patients with a combined 127 revision surgeries. We noted infection as the single most prevalent reason for revision (50%). Patients underwent an average of 2 surgeries before arriving at definitive implant or the end of study period. Our findings demonstrate a significant increase in cost relative to the primary arthroplasty in the BMI>45 population for infection. Surgical time was significantly longer than that of primary arthroplasty (190 vs. 150 minutes). Length of stay was also significantly increased (12.5 vs 5.6 days). Obesity with a BMI over 45 is associated with significantly higher cost of revision surgery relative to primary arthroplasty in the same population. Understanding the increased risk of revision and relatively higher costs in this population can allow for financial and administrative decisions to incorporate more granular data in the expectations associated with revision arthroplasty in both public and private payer systems.