Durability of One- and Two-Level Lumbar Fusion Surgeries: A Survivorship Analysis Based on Revision Surgery Rates

INTRODUCTION: Durability of surgical treatment is important to patients, providers, and payors. In addition to its effect on clinical outcomes and patient satisfaction, durability is a critical factor in evaluating the cost-effectiveness of care. One- and two-level lumbar fusion surgeries are among the most common spine procedures. The purpose of this study was to determine the prevalence, timing, and indications for revision surgery following short-segment lumbar fusions. METHODS: A single-institution, multisurgeon database was retrospectively reviewed for patients who underwent one- or two-level lumbar fusion between 2014 and 2018, with a minimum of four years of follow-up. Patients with surgery for trauma, tumor, or infection were excluded. Of the 5051 consecutive patients included, 64.5% (n = 3258) underwent one-level and 35.5% (n = 1793) underwent two-level fusion. Demographic data, surgical characteristics, and indications for revision surgery were collected through electronic medical record review. RESULTS: A total of 772 patients (15%) underwent unplanned lumbar revision surgery. The most common indications were adjacent segment disease (n = 288, 6%) at a mean of 1053 days postoperatively and nonunion (n = 207, 4%) at a mean of 649 days. Other causes of revision surgery included infection (2%), implant reposition (<1%), repeat decompression (<1%), hematoma evacuation (<1%), and revision durotomy repair (<1%). Revision surgery rates were similar between one- and two-level fusions (P = 0.073). CONCLUSION: One- and two-level lumbar fusion procedures demonstrated high durability with an overall revision surgery rate of 15%. The most common indications for revision surgery are adjacent segment disease and nonunion. These findings may inform surgical planning, guide preoperative counseling, and support future quality-improvement efforts.