Risk factors for recurrent lumbar disc herniation after discectomy

Purpose There are many reports about the risk factors for recurrence after lumbar disc surgery. However, there are none about whether lumbosacral transitional vertebrae (LSTV) are associated with recurrent lumbar disc herniation (LDH). We investigated various risk factors for recurrent LDH after discectomy including LSTV. Methods A total of 119 patients who had undergone a discectomy for L4-5 disc herniation were evaluated with a minimum follow-up of twoyears. Clinical parameters including age, gender, body mass index (BMI), and smoking status, and radiological parameters including type of herniated disc, degree of disc degeneration, LSTV, and sagittal range of motion (SROM) in flexion-extension radiography were evaluated. SROM was measured by the difference of the lordotic angle between the flexion and extension view. Results Recurrent disc herniation at L4-5 developed in 21 (17.6%) of the 119 patients. The mean period between primary surgery and recurrence was 17.6 +/- 21.1 months. LSTV was found in 11 (52.4%) of the 21 patients who had recurrence and seven (7.1%) of the 98 patients in the non-recurrent group. SROM at L4-5 was 11.68 +/- 4.24 degrees in the recurrent group and 9.04 +/- 3.65 degrees in the non-recurrent group with a significant difference (p=0.004). Multiple logistic regression analyses confirmed that LSTV and a larger SROM were significant risk factors for recurrent disc herniation at L4-5. Conclusions Lumbosacral transitional vertebrae and a hypermobile disc in flexion-extension radiography were found to be risk factors for recurrent lumbar disc herniation.