Increased Decentralization of Total Shoulder Arthroplasty Procedures Among Surgeons in the United States: A Nationwide Market Analysis.
Academic Article
Overview
abstract
BACKGROUND: Primary total shoulder arthroplasty (TSA) utilization has grown substantially in recent years. As procedure volume increases, understanding how operative volume is distributed across the surgeon workforce has become important, as concentration of cases among a limited number of high-volume surgeons versus broader decentralization has implications for training exposure, care accessibility, and long-term workforce capacity. However, trends in surgeon-level case volume distribution for TSA over time remain unclear. METHODS: A retrospective longitudinal analysis of primary TSA procedures performed in the United States from 2013 to 2023 was conducted using the Centers for Medicare and Medicaid Services (CMS) "Medicare Physician & Other Practitioners" dataset. Surgeons were included for any year in which they submitted ≥11 primary TSA claims. Case volume concentration was measured annually using the Herfindahl-Hirschman Index (HHI), applied at the surgeon level. State-level variation was assessed by calculating HHI separately for each state. Entrant surgeons were defined as those listed in the CMS database without having been listed in either of the two preceding years. Linear regression was used to evaluate temporal trends. RESULTS: National primary TSA volume increased from 32,208 procedures in 2013 to 93,167 in 2023. Surgeon-level case concentration decreased significantly, with HHI declining from 10.97 to 4.52 (β = -0.55 per year, p < 0.001). The number of surgeons performing TSA increased from 1,351 to 3,439. State-level analysis demonstrated widespread decentralization, with a mean ΔHHI of -955.9 from 2013 to 2023. The number of entrant surgeons increased from 463 to 792 (β = +36 per year, p = 0.004), while entrant surgeons' volume share declined from 30.4% to 23.0% (β = -0.008 per year, p = 0.050). CONCLUSIONS: Surgeon-level case volume concentration in TSA decreased substantially from 2013 to 2023, reflecting broader distribution of operative volume across a growing workforce. However, reductions in entrant surgeon case share suggest that increased TSA adoption may be primarily absorbed by existing surgeons rather than new entrants.
