INTRODUCTION
It is difficult to predict the improvement of low back pain (LBP) after decompression surgery for lumbar spinal stenosis (LSS). The purpose of this study was to evaluate the usefulness of the Brief Scale for Psychiatric Problems in Orthopaedic Patients (BS-POP) in predicting the improvement of LBP after surgery.
METHODS
This study was a historical cohort study. Among patients with LSS who underwent decompression surgery at our department between 2003 and 2019, 173 patients (101 males and 72 females, mean age 64.1 years) with preoperative LBP (Numerical rating scale (NRS) of 2 or higher) were included. A decrease in postoperative LBP of 2 or higher was defined as improving LBP. The subjects were divided into two groups according to preoperative BS-POP: high BS-POP and a normal group. The statistical analysis was performed by the Wilcoxon test, chi-square test, and logistic regression analysis. The p-value less than 0.05 was considered significant.
RESULTS
Twenty-four patients (13.9%) showed high preoperative BS-POP. The preoperative LBP was 5.8±2.3 in the high BS-POP group and 5.8±2.2 in the normal group, with no significant difference between the two groups. At one year postoperatively (82% follow-up), LBP improved in 99/124 (79%) patients in the normal BS-POP group and 6/17 (35.3%) patients in the high BS-POP group, showing a significant difference between the two groups (p < 0.05). The odds ratio [95% IC] of the normal BS-POP group to the high BS-POP group for postoperative improvement of LBP adjusted for age, gender, endoscopic use, presence of radiculopathy, degenerative spondylolisthesis, degenerative scoliosis, and lumbar kyphosis was 4.1 [1.4-12.3], indicating a significant association between BS-POP and improvement of LBP (p < 0.05).
DISCUSSION
This study showed that the patients with high BS-POP had less improvement in LBP at one year postoperatively. Preoperative evaluation of BS-POP may predict improvement in LBP after lumbar decompression surgery for LSS.