Establishing objective volume-outcome measures for anterior and posterior cervical spine fusion

There is a growing literature on the relationship between provider volume and patient outcomes, specifically within joint arthroplasty and lumbar spine surgery. Such benchmarks have yet to be established for many other spinal procedures, including cervical fusion. We sought to determine whether outcomes-based volume measures for both surgeons and hospitals can be established for cervical spine fusion procedures.

This was a retrospective review of patient data in the Florida Statewide Inpatient Dataset (SID; 2011-14). Patients identified in the Florida SID who underwent either anterior or posterior cervical fusion were identified along with the operative surgeons and the hospitals where the procedures were performed. Socio-demographic data, as well as medical and surgical characteristics were obtained, as were the development of complications and readmissions up to 90days following hospital discharge. Surgeon and hospital volume were plotted separately against the number of complications and readmissions in an adjusted spline analysis. Multivariable logistic regression analysis was subsequently performed to assess the effect of surgeon and hospital volume on post-operative complications and readmissions.

There were 8960 patients with posterior cervical fusion and 57,108 anterior cervical fusions (total=66,068) identified for inclusion in the analysis. The patients of low-volume surgeons were found to have an increased (OR 1.83; 95% CI 1.65, 2.02) likelihood of complications following anterior and posterior (OR 1.45; 95% CI 1.24, 1.69) cervical fusion. Low-volume surgeons demonstrated increased likelihood of readmission, irrespective of anterior (OR 1.37; 95% CI 1.29, 1.47) or posterior (OR 1.31; 95% CI 1.16, 1.48) approach. No clinically meaningful differences in the likelihood of complications or readmissions were detected between high- and low-volume hospitals.

This study demonstrates objective volume-outcome measures for surgeons who perform anterior and posterior cervical fusions. Our results have immediate applicability to clinical practice and may be used to benchmark procedural volume. Findings with respect to hospitals speak against the need for healthcare regionalization in this specific clinical context.