Risk Factors for Recurrent Lumbar Disc Herniation

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. (Medicine 95(2):e2378) Abbreviations: BMI = body mass index, CI = confidence interval, DHI = disc height index, HR = hazard ratio, LDH = lumbar disc herniation, NOS = Newcastle–Ottawa Scale, OR = odds ratio, rLDH = recurrent lumbar disc herniation, ROM = range of motion, RR = relative risk. iu, PhD, Lili Yu, MD, and Xiuchun Yu, MD disc herniation (LDH). Compared with conservative treatment, surgical intervention may have greater improvements or faster rates of pain relief. In spite of significant improvement in surgical technique, complications such as recurrent lumbar disc herniation (rLDH) do occur. The recurrence rate has been reported to vary between 5% and 15%. Secondary surgery will be more difficult due to epidural fibrosis and scarring. Moreover, reoperations lead to physical and psychological suffering for patients and substantial costs for society. Risk factors for rLDH are increasingly being investigated. Many estimated risk factors have been reported in previous studies, such as age, gender, body mass index (BMI), smoking, herniation type, diabetes, and herniation level. However, results in these previous studies were not always consistent. Regarding to gender, Kim et al reported that man was a risk factor for rLDH; however, many other observational studies did not find significant correlations between a man and rLDH. As for smoking, some studies revealed that smoking increased the risk of postoperative recurrence, whereas other studies found no significant difference between smokers and nonsmokers. Due to inconsistent results, reliable conclusions could not be drawn on these risk factors. In order to identify the predictors for rLDH, we have carried out a systematic review and meta-analysis based on the current evidence. The pooled estimates may help health professionals at givers, and patients to identify the potential population, prevent rLDH, and investigate the mechanism further.