Factors associated with the recurrence of lumbar disk herniation: biomechanical-radiological and demographic factors.

Many risk factors associated with recurrent lumbar disk herniation (RLDH) following lumbar discectomy (LD) have been reported. This study aimed to elucidate the biomechanicalradiological, clinical, and demographic factors that affect symptomatic RLDH prospectively.We collected prospective data of 988 consecutive patients with LDH who underwent LD at our department from January 2014 to December 2015. Patients who met the study criteria and were followed up postoperatively for more than 5 years were included (n = 816). Patients were divided into 3 groups; group 1 included patients who experienced symptomatic RLDH within the first postoperative 24 months (PO24M), group 2 included patients with symptomatic RLDH after PO24M, and group 3 included the patients who hadn't experienced symptomatic RLDH/LDH. The preoperative biomechanicalradiological, clinical, and the patients' demographic characteristics were compared among the groups.A total of 816 patients with 842 LDH met our study criteria. The mean age at the first LD was 46.9 years. The mean follow-up period was 72.8 months. The preoperative trauma history, postoperative trauma history, and BMI > 24.5 kg/m were independent risk factors for RLDH. Large sROM at the L4-5 level and a higher intervertebral disk height index (IDH) were significantly higher in groups 1 and 2.Biomechanical-radiological and demographic factors can affect the incidence of symptomatic RLDH. To reduce the risk of RLDH, patients with these risk factors should receive more attention during surgical interventions. The patients should avoid gaining weight and potential traumatic accidents.