Risk Factors for Recurrent Lumbar Disc Herniation: A Systematic Review and Meta-Analysis

Recurrent lumbar disc herniation (rLDH) is a common complication following primary discectomy. This systematic review aimed to investigate the current evidence on risk factors for rLDH.Cohort or case-control studies addressing risk factors for rLDH were identified by search in Pubmed (Medline), Embase, Web of Science, and Cochrane library from inception to June 2015. Relevant results were pooled to give overall estimates if possible. Heterogeneity among studies was examined and publication bias was also assessed.A total of 17 studies were included in this systematic review. Risk factors that had significant relation with rLDH were smoking (OR 1.99, 95% CI 1.53-2.58), disc protrusion (OR 1.79, 95% CI 1.15-2.79), and diabetes (OR 1.19, 95% CI 1.06-1.32). Gender, BMI, occupational work, level, and side of herniation did not correlate with rLDH significantly.Based on current evidence, smoking, disc protrusion, and diabetes were predictors for rLDH. Patients with these risk factors should be paid more attention for prevention of recurrence after primary surgery. More evidence provided by high-quality observational studies is still needed to further investigate risk factors for rLDH.