Caudal Lumbar Disc Herniations Are More Likely to Require Surgery for Symptom Resolution

Study Design: Retrospective study. Objectives: We examined the impact that location of a lumbar disc herniation has on the likelihood that a patient will require surgery after at least 6 weeks of nonoperative management. Methods: Using ICD-10 codes M51.26 and M51.27, we identified patients at a single academic institution from 2015 to 2016 who received a diagnosis of primary lumbar radicular pain, had magnetic resonance imaging confirming a lumbar disc herniation, and underwent at least 6 weeks of nonoperative management. Patients experiencing symptoms suggesting cauda equina syndrome or progressive motor deficits were excluded. Results: Five hundred patients met inclusion/exclusion criteria. Twenty-nine (5.8%) had L3-L4 herniations, 245 (49.0%) had L4-L5 herniations, and 226 (45.2%) had L5-S1 herniations. Overall, 451 (90.2%) patients did not undergo surgery within 1 year of diagnosis. Nonsurgical patients had an average herniation size occupying 31.2% of the canal, compared with 31.5% in patients who underwent surgery. While herniation size, age, sex, and race failed to demonstrate a statistical association with the likelihood for surgery, location of disc herniation demonstrated a strong association. L3-L4 and L4-L5 herniations had odds ratios of 0.19 and 0.45, respectively, relative to L5-S1 herniations (P =.0047). Patients were more than twice as likely to require a surgery on an L5-S1 herniation in comparison with an L4-L5 herniation (P <.05). L3-L4 herniations rarely required surgery. Conclusions: Patients with caudal lumbar disc herniations were more likely to require surgery after at least 6 weeks of conservative management than those with disc herniations in the mid-lumbar spine.