Reoperation Rates for Symptomatic Nonunions in Anterior Cervical Fusions From a National Spine Registry

Study Design. A retrospective cohort study with chart review. Objective. To determine the reoperation rates for symptomatic nonunions for 1-level, 2-level, and 3-level anterior cervical discectomies and fusions (ACDFs) from a national spine registry. Summary of Background Data. There is very little data reported in the literature on reoperation rates for symptomatic nonunions after ACDFs. The reported nonunion rates are primarily based on radiographical evidence, although some of these may be asymptomatic. Similarly, there may be symptomatic patients with nonunions who elect not to have a reoperation. We think, however, data from a national spine registry provide a realistic and unbiased assessment of routine cervical spine fusion care and represent a heterogeneous population with varied indications and surgical techniques and are best suited to determine reoperations for symptomatic nonunions. Methods. Using data from a Spine Implant Registry developed at a large integrated health care system (Kaiser Permanente), patients with ACDFs between January 2009 and December 2012 with 2-year follow-up were identified. Patient characteristics, admitting diagnosis, and number of levels fused were extracted from the registry. Reoperations for symptomatic nonunions from the index spinal procedure were identified by chart review. Results. A cohort of 1054 patients with more than 2 years of follow-up were found to have reoperations for nonunions of 0.2%, 2.9%, and 6.5% for 1-level, 2-level, and 3-level ACDFs, respectively. Conclusion. A large cohort of ACDF patients with more than 2 years of follow-up had reoperations for nonunion rates significantly lower than reported in the literature for radiographical nonunions. We think our data add to the literature an important parameter (reoperations for nonunion rates) and provide useful information for patients, spine surgeons, and health care payers.