A novel classification and clinical evaluation of various morphologies of calcified lumbar disc herniation treated using unilateral biportal endoscopic technique.

OBJECTIVE: To introduce a new classification of calcified lumbar disc herniation (CLDH), and to evaluate the clinical performance of the unilateral biportal endoscopic technique (UBE) in treating CLDH. METHODS: Between April 2023 and May 2025, 119 total lumbar disc herniation patients were treated with UBE at the participating hospital. The subjects were sorted into one of two groups, the CLDH group (N = 52) or uncalcified lumbar disc herniation group (ULDH, N = 67), based on the calcification of the intervertebral disc. Furthermore, the CLDH group was subdivided into three distinct categories in an attempt to conduct comparative analysis of clinical efficacies across all sub-groups. The visual analogue scale (VAS) and Oswestry disability index (ODI) were recorded at different time-points, specifically, pre-operation, 3-day post-operation, 1-month post-operation, 3-month post-operation, and at the last follow-up. The MacNab classification outcomes were recorded at the last follow-up. Any complications were recorded during follow-ups. RESULTS: All patients underwent successful surgical interventions without any reports of serious postoperative complications. The ULDH patients required a shorter operative time, relative to the CLDH patients (69.7 ± 11.6 min vs., 75.9 ± 11.9 min P < 0.05). Despite this difference, all patients experienced comparable blood loss, and hospitalization duration (21.9 ± 4.8 ml vs. 21 ± 5.0 ml, P > 0.05; 4.0 ± 0.4 d vs. 3.9 ± 0.4 d, P > 0.05). Our postoperative assessments revealed remarkable improvements in both VAS and ODI scores at all evaluated time points (3-day, 1-month, 3-month post-operation, and final follow-up), relative to the preoperative baseline values (p < 0.05). More importantly, these improvements demonstrated consistent statistical significance across the entire follow-up period. Of note, we observed no marked intergroup differences in either scoring system at any postoperative evaluation time point. At the final follow-up, 94.8% of CLDH patients achieved excellent/good clinical outcomes. The ULDH patients also demonstrated comparable therapeutic efficacy with 95.5% patients exhibiting similar MacNab criteria classification (p > 0.05). Using this classification, the number of categories were as follows: 29 cases, Hill type: 17 cases, and Peak type: 6 cases. No substantial differences were evident in clinical efficacies among the three subgroups. The peak patient group experienced a longer surgical duration, relative to the stone patient group, who, in turn, required a longer operation time than the hill group, and the differences were statistically significant (p < 0.05). CONCLUSIONS: The Song's classification system has initially demonstrated significant value in guiding personalized surgical decision-making. Different strategic approaches of UBE provide alternative surgical options, thereby optimizing the treatment plan for patients with CLDH.