Variability in Spine Surgery Procedures Performed During Orthopaedic and Neurological Surgery Residency Training

BACKGROUND: Current spine surgeon training in the United States consists of either an orthopaedic or neurological surgery residency, followed by an optional spine surgery fellowship. Resident spine surgery procedure volume may vary between and within specialties. METHODS: The Accreditation Council for Graduate Medical Education surgical case logs for graduating orthopaedic surgery and neurosurgery residents from 2009 to 2012 were examined and were compared for spine surgery resident experience. RESULTS: The average number of reported spine surgery procedures performed during residency was 160.2 spine surgery procedures performed by orthopaedic surgery residents and 375.0 procedures performed by neurosurgery residents; the mean difference of 214.8 procedures (95% confidence interval, 196.3 to 231.7 procedures) was significant (p = 0.002). From 2009 to 2012, the average total spinal surgery procedures logged by orthopaedic surgery residents increased 24.3% from 141.1 to 175.4 procedures, and those logged by neurosurgery residents increased 6.5% from 367.9 to 391.8 procedures. There was a significant difference (p < 0.002) in the average number of spinal deformity procedures between graduating orthopaedic surgery residents (9.5 procedures) and graduating neurosurgery residents (2.0 procedures). There was substantial variability in spine surgery exposure within both specialties; when comparing the top 10% and bottom 10% of 2012 graduates for spinal instrumentation or arthrodesis procedures, there was a 13.1-fold difference for orthopaedic surgery residents and an 8.3-fold difference for neurosurgery residents. CONCLUSIONS: Spine surgery procedure volumes in orthopaedic and neurosurgery residency training programs vary greatly both within and between specialties. Although orthopaedic surgery residents had an increase in the number of spine procedures that they performed from 2009 to 2012, they averaged less than half of the number of spine procedures performed by neurological surgery residents. However, orthopaedic surgery residents appear to have greater exposure to spinal deformity than neurosurgery residents. Furthermore, orthopaedic spine fellowship training provides additional spine surgery case exposure of approximately 300 to 500 procedures; thus, before entering independent practice, when compared with neurosurgery residents, most orthopaedic spine surgeons complete as many spinal procedures or more. Although case volume is not the sole determinant of surgical skills or clinical decision making, variability in spine surgery procedure volume does exist among residency programs in the United States.