Predictors of improvement in low back pain after lumbar decompression surgery: Prospective study of 140 patients.

BACKGROUND: Lumbar decompression surgery is often used to treat neurological symptoms of the lower extremity as a result of lumbar disease. However, this method also leads to the improvement of the accompanying low back pain (LBP). We studied the extent of LBP improvement after lumbar decompression surgery without fusion and the associated preoperative factors.

METHODS: Patients (n = 140) with lumbar spinal stenosis (n = 90) or lumbar disc herniation (n = 50) were included. To evaluate the change in LBP, VAS scores and the Oswestry disability index scores were measured before surgery and 2 weeks, 3 months, and 6 months after surgery. The predictors of residual LBP were investigated using logistic regression analyses.

RESULTS: In total, 140 patients were examined. The VAS scores for LBP before surgery and 2 weeks, 3 months, and 6 months after surgery were 4.4 ± 3.0 (mean ± standard deviation), 1.1 ± 1.5, 1.3 ± 1.8, and 1.9 ± 2.2, respectively. LBP significantly improved 2 weeks after surgery (P < 0.001), stabilized between 2 weeks and 3 months after surgery, but was significantly aggravated 3-6 months after surgery (P < 0.001). At 6 months after surgery, 67 (47.9%) patients had a VAS score of >1. The predictors of residual LBP included severe preoperative LBP, degenerative scoliosis and the size of the Cobb angle. The independent predictors, determined by multivariate analysis were degenerative scoliosis and the size of the Cobb angle.

CONCLUSIONS: LBP was alleviated at 2 weeks after lumbar decompression surgery for lumbar disc herniation and lumbar spinal stenosis. The predictors of residual LBP after decompression included more severe LBP at baseline, degenerative scoliosis and the size of Cobb angle.

LEVEL OF EVIDENCE: Level 3.