JOA - 2026-05-19 - Journal Article
Diverging Surgeon Distribution in Primary Versus Revision Arthroplasty: A National Analysis.
Persaud SG, Kucherina A, Zepeda KE, Burgio C, Cheng S, Vigdorchik JM, Debbi EM
Topics
Key Takeaway
Revision THA consolidated dramatically (HHI 42.4 to 132.8) while primary THA and TKA decentralized over 2013–2023 in the Medicare population.
Summary Depth
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Summary
This study analyzed Medicare fee-for-service claims from 2013–2023 to characterize surgeon-level concentration in primary and revision THA/TKA using the Herfindahl-Hirschman Index. Primary THA and TKA decentralized (HHI 2.7→2.0 and 1.7→1.5, respectively), while revision THA concentrated sharply (HHI 42.4→132.8, β=+8.37/year, P<0.001) and revision TKA remained persistently concentrated. Entrant surgeons contributed 12–18% of annual primary arthroplasty volume throughout the study period.
Key Limitation
CPT-code–based identification cannot distinguish complexity within revision categories (e.g., single-component exchange vs. full revision with augments), potentially conflating low- and high-complexity revisions in the concentration metrics.
Original Abstract
BACKGROUND
Total hip (THA) and total knee arthroplasty (TKA) utilization has increased substantially over the past decade, highlighting the importance of understanding how operative volume is distributed among surgeons. While prior studies have focused on consolidation at the health-system level, surgeon-level procedural concentration remains incompletely characterized.
METHODS
A retrospective analysis of Medicare fee-for-service claims from 2013 to 2023 was performed using a national Medicare administrative claims dataset. The primary and revision THAs and TKAs were identified using Current Procedural Terminology (CPT) codes, including surgeons performing ≥ 11 procedures annually. Surgeon-level case concentration was assessed using the Herfindahl-Hirschman Index (HHI), with state-level variation evaluated using change in HHI (2023 minus 2013). Entrant surgeons were defined as those who had no cases in the prior two years. Temporal trends were assessed using linear regressions.
RESULTS
Primary THA volume increased from 166,730 to 274,801 and TKA from 390,710 to 526,893 between 2013 and 2023, with corresponding increases in median annual surgeon volume (THA: 21 to 26;
TKA
27 to 31). Surgeon-level HHI declined for primary THA (2.7 to 2.0; β = -0.064/year, P < 0.001) and TKA (1.7 to 1.5; β = -0.016/year, P = 0.022), indicating decentralization. Revision THA volume decreased (5,667 to 1,814) with increasing HHI (42.4 to 132.8; β = +8.37/year, P < 0.001), while revision TKA remained persistently concentrated. Entrant surgeons accounted for 12 to 18% of annual primary arthroplasty volume.
CONCLUSION
The primary THAs and TKAs have become increasingly dispersed over the last decade, whereas revision arthroplasty remained concentrated among specialist high-volume surgeons, indicating contrasting workforce patterns.