Reassessing Total Joint Arthroplasty Case Volumes in The United States: Accounting for Ultra-Low-Volume Surgeons.

Abstract

Reported average total joint arthroplasty (TJA) volumes among orthopaedic surgeons in the United States range from 22 to 65 cases per year. However, this figure is heavily influenced by a large cohort of ultra-low-volume surgeons who perform fewer than 10 TJAs annually, representing a relatively small number of patients. This study reassessed surgeon volume trends by taking ultra-low-volume surgeons into account while also quantifying the average caseload of a typical TJA patient's surgeon. A national insurer database was used to identify all patients who underwent primary total knee arthroplasty (TKA) and total hip arthroplasty (THA) from 2016 to 2023. Surgeon volume was defined as the number of TJAs performed in a calendar year. Surgeons were categorized as standard-volume (≥ 10 cases/year) or ultra-low-volume (< 10 cases/year). Descriptive statistics were used to characterize trends before and after excluding ultra-low-volume surgeons. The average caseload of a typical TJA patient's surgeon was calculated by averaging surgeon volume on a patient-by-patient basis. Between 2016 and 2023, mean case volume increased from 35.5 to 37.7 while the median decreased from six to four. The percentage of ultra-low-volume surgeons (< 10 cases) increased from 57.0% of all surgeons in 2016 to 60.0% in 2023, accounting for only 4.1% of all cases in 2016 and 3.8% in 2023. Standard-volume surgeons accounted for 95.9% of all cases in 2016 and 96.2% in 2023. After including only standard-volume surgeons, the mean number of cases per year increased from 79.1 to 90.7, and the median increased from 44 to 53. Moreover, the average patient undergoing TJA was treated by a surgeon whose annual caseload increased from 188.7 to 192.8. Annual case volume averages are heavily skewed by ultra-low-volume surgeons, obscuring an increase in the number of cases performed by standard joint arthroplasty surgeons. The typical TJA patient is treated by a high-volume surgeon whose caseload has increased from 2016 to 2023.