134 How to Spot the Recurring Lumbar Disc? Risk Factors for Recurrent Lumbar Disc Herniation in Adult Patients with Lumbar Disc Prolapse: A Systematic Review and Meta-Analysis

Abstract

Abstract Aim Despite a fast-growing evidence-base examining the relationship of certain clinical and radiological factors such as smoking, BMI and herniation-type with recurrent lumbar disc herniation (rLDH), there remains much debate around which factors are clinically important. We conducted a systematic review and meta-analysis to identify risk factors for rLDH in adults after primary disc surgery. Method A systematic literature search was performed using Ovid-Medline, EMBASE, Cochrane library and Web of Science databases from inception to 23rd June-2022. Observational studies of adult patients with radiologically confirmed rLDH ≥3 months after the initial surgery were included, and their quality assessed using the Quality-In-Prognostic-Studies (QUIPS) appraisal tool. Meta-analyses of univariate and multivariate data and a sensitivity-analysis for rLDH post-microdiscectomy were carried out. Results Twelve studies (n=4497, mean-age: 47.3; 34.5% female) were included, of which 11 studies were meta-analysed (n=4235). The mean follow-up was 38.4 months. Mean recurrence-rate was 13.1% and mean time-to-recurrence was 24.1 months (range: 6-90 months). Clinically, older age (OR:1.04, 95% CI:1.00-1.08, n=1014), diabetes mellitus (OR:3.82, 95% CI:1.58-9.26, n=2330) and smoking (OR:1.80, 95% CI:1.03-3.14, n=3425) increased likelihood of recurrence. Radiologically, Modic-change type-2 (OR:7.93, 95% CI:5.70-11.05, n=1706) and disc-extrusion (OR:12.23, 95% CI:8.60-17.38, n=1706) increased likelihood of recurrence. The evidence did not support an association between rLDH and sex; BMI; occupational-labour; alcohol-consumption; Pfirmann-grade, or herniation-level. Conclusions Older patients, smokers, patients with diabetes, those with type-2 Modic-changes or disc-extrusion are more likely to experience rLDH. Higher quality studies with robust adjustment of confounders are required to determine the clinical bearing of all other potential risk factors on rLDH.