Summary

Using time-driven activity-based costing, this study found increasing operating room time and number of anchors were predictive of increasing surgical cost. Surgeries in the top-decile of total cost were 19% higher the remainder of the cohort. The largest proportions of surgical cost were operating room consumables, including implants, and surgical personnel cost.

Abstract

Background

There is a paucity of data investigating factors influencing the cost of hip arthroscopy despite a simultaneous increase in emphasis on bundled-payment healthcare models and hip arthroscopy procedure volume. Our study uses the novel cost accounting methodology, time-driven activity-based costing (TDABC), to approach this topic at a granular level. We sought to elucidate preoperative and intraoperative factors of outpatient arthroscopic labral repair of the hip associated with increased cost.

Methods

A retrospective analysis of prospectively collected data was performed for patients undergoing elective outpatient hip arthroscopy with labral repair between 2020 and 2021. Indexed TDABC data was used to represent cost of care breakdowns. Patients in the top-decile of cost were defined as high-cost, and cost category variance was determined as a ratio of the 10th to 90th percentile. Multivariate linear regression modeling was used to test for associations between preoperative factors (e.g., demographics, comorbidities, American Society of Anesthesiology [ASA] and radiographic findings) and perioperative factors (e.g., anesthesia selection, anchors, total stay time, and operating room (OR) time) with total cost. For sub-analysis of factors influencing operating room time, we included surgical procedures performed concomitant to labral repair.

Results

In total, 151 patients were included in analysis. Consumables were the main driver (64%) of total outpatient cost, consisting of operating room consumables (42%) and implants (22%). Surgical personnel costs (30%) were the second largest component of total cost. There was a 1.19-fold variation in total cost between patients in the top-decile of cost and the remainder of the cohort. Factors contributing to this variation in cost in decreasing order of magnitude were implant cost (1.36x), surgical personnel (1.20x), and OR consumables (1.15x). The multivariate linear regression model indicated OR time (Standardized ß=0.504; p < 0.001) and number of anchors used (Standardized ß=0.443; p < 0.001) were significant predictors of increased cost. Multivariable linear regression modeling revealed femoroplasty (ß = 15.819; P = 0.008), chondroplasty (ß = 11.891; P < 0.001), excision of Os Acetabuli (ß = 13.889; P = 0.037), and trochanteric bursectomy (ß = 16.250; P = 0.044) were all independently associated with increasing operating room time in minutes.

Conclusion

Efforts to reduce operating room consumable costs, including anchor cost, and operating room time may decrease overall surgical cost. These reductions may translate into patient and facility savings. Further investigation into the factors contributing to the cost of hip arthroscopy and the total cost of care for hip conditions are warranted.