Percutaneous Endoscopic Lumbar Discectomy for Calcified Lumbar Disc Herniation: A Retrospective Cohort Study, Systematic Review and Meta-Analysis

BACKGROUND: Calcified lumbar disc herniation (CLDH) is a subtype characterized by calcification, leading to increased surgical complexity. Percutaneous endoscopic lumbar discectomy (PELD) is a minimally invasive technique, but its effectiveness and complications in CLDH patients remain to be fully evaluated. OBJECTIVE: To assess the effectiveness and complications of PELD in treating CLDH patients. STUDY DESIGN: A retrospective cohort study combined with a systematic review and meta-analysis. SETTING: Department of Pain Medicine, an affiliated hospital of a university. METHODS: Data from patients who underwent PELD in our department between March 2020 and May 2021 were collected. Forty CLDH patients were included in the study group, and equally matched cases with uncalcified lumbar disc herniation (UCLDH) served as controls. A systematic search was conducted on October 5, 2022, using EMBASE, PubMed, Cochrane Library, the China Biology Medicine disk, the China National Knowledge Infrastructure, and the Wanfang databases, following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. A random-effects model was used to calculate pooled results. RESULTS: Eighty patients were included in the retrospective cohort, and 41 studies were included in the meta-analysis. Both the retrospective cohort and meta-analysis consistently showed a significant decrease in visual analog scale (VAS) and Oswestry Disability Index (ODI) scores in the CLDH group after the operation. In the retrospective cohort, the excellent or good rate according to the MacNab classification was 85%, with no reported complications. The meta-analysis revealed a pooled excellent or good rate of 91.8% and a low complication rate of 2.9%. Combining the findings from our retrospective cohort and meta-analysis, we observed that the CLDH group had longer operation times and slightly higher postoperative ODI scores compared to the UCLDH group. LIMITATIONS: Small sample size and lack of long-term follow-up in the retrospective cohort, as well as limited inclusion of comparative studies in the meta-analysis. CONCLUSION: PELD is an effective and safe treatment option for CLDH patients. In comparison to UCLDH patients, CLDH patients may experience longer operation times and slightly slower functional recovery than those with UCLDH. KEY WORDS: Calcification, lumbar disc herniation, percutaneous endoscopic lumbar discectomy, effectiveness, complication