Effect of Fellow Involvement and Experience on Patient Outcomes in Spine Surgery

Introduction: Investigations in spine surgery have demonstrated that trainee involvement correlates with increased surgical time, readmissions, and revision surgeries; however, the specific effects of spine fellow involvement remain unelucidated. This study aims to investigate the isolated effect of fellow involvement on surgical timing and patient-reported outcomes measures (PROMs) after spine surgery and evaluate how surgical outcomes differ by fellow experience. Methods: All patients aged 18 years or older who underwent primary or revision decompression or fusion for degenerative diseases and/or spinal deformity between 2017 and 2019 at a single academic institution were retrospectively identified. Patient demographics, surgical factors, intraoperative timing, transfusion status, length of stay (LOS), readmissions, revision rate, and preoperative and postoperative PROMs were recorded. Surgeries were divided based on spine fellow participation status and occurrence in the start or end of fellowship training. Univariate and multivariate analyses compared outcomes across fellow involvement and fellow experience groups. Results: A total of 1,108 patients were included. Age, preoperative diagnoses, number of fusion levels, and surgical approach differed markedly by fellow involvement. Fellow training experience groups differed by patient smoking status, preoperative diagnosis, and surgical approach. On univariate analysis, spine fellow involvement was associated with extended total theater time, induction start to cut time, cut to close time, and LOS. Increased spine fellow training was associated with reduced cut to close time and LOS. On regression, fellow involvement predicted cut to close extension while increased fellow training experience predicted reduction in cut to close time, both independent of surgical factors and assisting residents or physician assistants. Transfusions, readmissions, revision rate, and PROMs did not differ markedly by fellow involvement or experience. Conclusion: Spine fellow participation predicted extended procedural duration. However, the presence of a spine fellow did not affect long-term postoperative outcomes. Furthermore, increased fellow training experience predicted decreased procedural time, underscoring a learning effect. Availability of Data and Material: The data sets generated during and/or analyzed during the current study are available from the corresponding author on reasonable request.