The role of collagen pathologies and ligamentous laxity in lumbar disc herniation and its recurrence: a systematic review and meta-analysis.

BACKGROUND

Lumbar disc herniation is a leading cause of low back pain and radiculopathy, with substantial healthcare and socioeconomic impacts. While age-related degeneration and biomechanical stress are established contributors, emerging evidence implicates systemic connective tissue abnormalities, particularly collagen disorders and ligamentous laxity, in both the development and recurrence of lumbar disc herniation. Understanding these associations may inform preventive and therapeutic strategies.

METHODS

A systematic review and meta-analysis were conducted using PubMed, combining the terms "lumbar disc herniation," "collagen," and "ligamentous laxity." Following screening of 218 records, 57 full-text articles were assessed, with 22 meeting inclusion criteria and 10 providing quantitative data for meta-analysis. Extracted data included sample characteristics, collagen gene involvement, presence of ligamentous laxity, and outcomes such as risk ratios (RRs) or odds ratios (ORs) for primary and recurrent LDH. Pooled RRs with 95% confidence intervals were calculated using a random-effects model.

RESULTS

Patients with collagen anomalies or clinical ligamentous laxity demonstrated a significant increased risk of LDH with a pooled RR of 2.12 (95% CI 1.58-2.84). Mutations in COL1A1, COL1A2, COL9A3, and COL11A1 were associated with higher incidence of disc degeneration and symptomatic herniation. Ligamentous laxity and degenerative changes in the ligamentum flavum contributed mechanically to disc instability. Histological studies showed persistent matrix fragmentation and impaired collagen remodelling in recurrent LDH, indicating that connective tissue integrity influences both initial herniation and post-surgical recurrence.

CONCLUSIONS

Collagen disorders and ligamentous laxity are associated with an increased risk of primary and recurrent LDH through combined molecular and mechanical mechanisms. These findings highlight the potential importance of connective tissue vulnerability in affected patients. While tailored interventions, including annular reinforcement, dynamic stabilization, and modified rehabilitation, may mitigate risk and improve outcomes, further research is required before routine genetic or biomechanical assessments can be incorporated into clinical evaluation or surgical planning.