An ACGME-based comparison of neurosurgical and orthopedic resident training in adult spine surgery via a case volume and hours-based analysis

OBJECTIVE In a 2014 analysis of orthopedic and neurological surgical case logs published by the Accreditation Council for Graduate Medical Education (ACGME), it was reported that graduating neurosurgery residents performed more than twice the number of spinal procedures in their training compared with graduating orthopedic residents. There has, however, been no follow-up assessment of this trend. Moreover, whether this gap in case volume equates to a similar gap in procedural hours has remained unstudied. Given the association between surgical volume and outcomes, evaluating the status of this disparity has value. Here, the authors assess trends in case volume and procedural hours in adult spine surgery for graduating orthopedic and neurological surgery residents from 2014 to 2019. METHODS A retrospective analysis of ACGME case logs from 2014 to 2019 for graduating orthopedic and neurological surgery residents was conducted for adult spine surgeries. Case volume was converted to operative hours by using periprocedural times from the 2019 Medicare/Medicaid Physician Fee Schedule. Graduating residents' spinal cases and hours, averaged over the study period, were compared between the two specialties by using 2-tailed Welch's unequal variances t-tests (alpha = 0.05). Longitudinal trends in each metric were assessed by linear regression followed by crossspecialty comparisons via tests for equality of slopes. RESULTS From 2014 to 2019, graduating neurosurgical residents logged 6.8 times as many spinal cases as their orthopedic counterparts, accruing 431.6 (95% CI 406.49-456.61) and 63.8 (95% CI 57.08-70.56) cases (p < 0.001), respectively. Accordingly, graduating neurosurgical residents logged 6.1 times as many spinal procedural hours as orthopedic surgery residents, accruing 1020.7 (95% CI 964.70-1076.64) and 166.6 (95% CI 147.76-185.35) hours (p < 0.001), respectively. Over these 5 years, both fields saw a linear increase in graduating residents' adult spinal case volumes and procedural hours, and these growth rates were higher for neurosurgery (+16.2 cases/year vs +4.4 cases/year, p < 0.001; +36.4 hours/year vs +12.4 hours/year, p < 0.001). CONCLUSIONS Graduating neurosurgical residents accumulated substantially greater adult spinal case volumes and procedural hours than their orthopedic counterparts from 2014 to 2019. This disparity has been widened by a higher rate of growth in adult spinal cases among neurosurgery residents. Accordingly, targeted efforts to increase spinal exposure