Risk Factors of Low Back Pain Aggravation After Tubular Microdiscectomy of Lumbar Disc Herniation

Although lumbar disc herniation (LDH) patients' sciatic symptoms such as leg pain can be improved by decompressive surgery, some patients report postoperative aggravated low back pain (LBP). However, the exact reason for this phenomenon remained unknown. We retrospectively analyzed the prospectively collected LDH data of patients who underwent tubular microdiscectomy between December 2015 and December 2020. The patients were divided into aggravated and non-aggravated group according to whether the postoperative LBP visual analogue scale (VAS) score was higher than the preoperative score. We analyzed the relationship of the clinical and radiologic parameters with aggravated LBP. Postoperative aggravated LBP cases accounted for 14.1% (57 of 404) of this series. Of the 57 patients, 88% (50 of 57) had mild postoperative LBP aggravation (1–2), and 12% (7 of 57) had severe LBP aggravation (>2). The preoperative LBP VAS score of the aggravated group was significantly lower than that of the non-aggravated group (P < 0.001), while the LBP VAS score and Oswestry Disability Index at final follow-up was significantly higher in the aggravated group (P < 0.05). Additionally, the proportion of preoperative moderate-to-severe multifidus fatty atrophy (MFA) and lumbar facet joint degeneration (LFJD) was significantly higher in the aggravated group. A multiple stepwise logistic regression analysis indicated that the preoperative LBP VAS score (P < 0.001, odds ratio 0.266, 95% CI 0.161–0.439) and MFA (P < 0.001, odds ratio 4.491, 95% CI 2.092-9.640) were the risk factors for postoperative aggravated LBP. A preoperative lower LBP VAS score and moderate-to-severe MFA were associated with postoperative aggravated LBP. This will provide important guidance for patient's preoperative assessment and education.