Lumbar disc herniation with giant extruded or sequestered morphology: feasibility of a conservative-first strategy and the stratification value of contrast-enhanced MRI.

PURPOSE: To assess the 24-month feasibility of a conservative-first strategy in patients meeting predefined criteria for giant extruded or sequestered lumbar disc herniation (LDH), and to explore the stratification value of contrast-enhanced MRI. METHODS: This prospective observational cohort included 60 consecutive patients without cauda equina syndrome or progressive neurological deficit. The primary endpoint was surgery conversion. Japanese Orthopaedic Association (JOA) and Oswestry Disability Index (ODI) scores were prespecified at baseline, 6 months, and 24 months after treatment initiation. Secondary outcomes included nonoperative success, herniation volume change, and MRI enhancement phenotype. Time to surgery was analyzed using Kaplan-Meier methods. RESULTS: Seven patients underwent elective surgery within 24 months, giving a conversion rate of 11.7% (95% CI 5.8-22.2%); all conversions occurred within the first 6 months after treatment initiation. Nonoperative success was achieved in 53 patients (88.3%). In these patients, JOA improved from 14.42 ± 2.13 to 24.19 ± 2.39, and ODI decreased from 27.79 ± 2.59 to 5.42 ± 2.24 at 24 months (both P < 0.001). No surgery conversion occurred in the rim-enhancement group (0/21 vs. 7/39, P = 0.085). Rim enhancement was associated with greater 6-month volume reduction (P = 0.015). CONCLUSION: In this single-center cohort, most patients meeting predefined eligibility criteria did not undergo surgery within 24 months, and all conversions were elective. Rim enhancement was associated with greater 6-month volume reduction, but its value for surgery conversion remained exploratory and it should not replace comprehensive neurological and functional assessment.