Risk factor analysis of persistent low back pain after microdiscectomy: A retrospective study

Microdiscectomy is an effective and safe treatment for patients with symptomatic lumbar disc herniation (LDH) that is refractory to conservative interventions. However, some patients experience persistent low back pain (PLBP) after microdiscectomy that is secondary to progressive disc degeneration and segmental instability. This study aimed to clarify the definition of PLBP and analyze its prevalence and associated risk factors.

This retrospective study included patients who underwent microdiscectomy for LDH at our hospital between 2015 and 2019. We divided this cohort into patients who did (PLBP group) or did not (non-PLBP group) experience PLBP after microdiscectomy and compared their clinical, radiological, and anatomical parameters. We analyzed the relationship between PLBP post-microdiscectomy and the following variables: age, sex, disk herniation level, recurrent disk herniation, body mass index (BMI), modic changes on MRI, facet subluxation, preoperative lumbar pain, and lumbosacral transitional vertebrae (LSTV).

PLBP after microdiscectomy was diagnosed in 99 (29.8 %) of the 332 patients enrolled in this study. Based on our multivariate logistic regression analysis, L5-S1 disc herniation level, recurrent disc herniation after microdiscectomy, obesity, modic changes on preoperative MRI, and facet subluxation were independent risk factors for PLBP post-microdiscectomy. Women and patients aged <50 years showed a trend of increased risk for developing PLBP after microdiscectomy; however, this trend did not reach statistical significance.

PLBP after microdiscectomy is a frequent and understudied condition. We found that an L5-S1 disc herniation level, recurrent disc herniation, obesity, modic MRI changes, and facet subluxation were risk factors for PLBP after microdiscectomy. These results can help surgeons in developing a better understanding of lumbar microdiscectomy outcomes.