Relief of Low Back Pain After Posterior Decompression for Lumbar Spinal Stenosis

Masaaki Kakiuchi, MD, PhD; Eiji Wada, MD, PhD; Takeo Harada, MD; Ryoji Yamasaki, MD, PhD; Wakaba Fukushima, MD, PhD

Disclosures

Spine. 2021;46(18):E966-E975. 

In This Article

Abstract and Introduction

Abstract

Study Design. A retrospective study.

Objective. The aim of this study was to confirm that decompression for lumbar spinal stenosis (LSS) relieves low back pain (LBP) as adequately as it relieves leg pain and to identify predictors for inadequate LBP relief.

Summary of Background Data. Although decompression for LSS is generally thought to yield worse results for LBP than for leg pain, some studies have reported similar improvements in pain scores between LBP and leg pain. To treat LBP or take measures to prevent inadequate LBP relief, reliable predictors for LBP relief should be identified.

Methods. We retrospectively reviewed 175 patients who underwent posterior element-preserving decompression and evaluated the relief of LBP and leg pain using numeric rating scales (NRSs). Associations between demographic, clinical, or imaging parameters and LBP relief at 1 and 4 years were analyzed by stepwise linear regression analyses. The imaging parameters included Modic change type 1, disc degeneration, foraminal stenosis, vertebral slipping (within Grade 1), scoliosis (<15°) and lordosis.

Results. The mean improvements in LBP and leg pain NRS scores from baseline were 5.22 and 4.70 points (P = 0.064, paired t test) at 1 year and 5.12 and 4.62 points (P = 0.068) at 4 years, respectively. Poor LBP scores at 4 years were significantly associated with long-lasting LBP (beta = 0.31, P < 0.0001) and moderate or severe arm symptoms with cervical spinal cord compression or intramedullary hyperintense signal on T2-weighted MRI (beta = 0.22, P = 0.0014). The imaging parameters of the lumbar spine failed to show clear associations with poor LBP scores at 4 years, although Modic change type 1 showed a significant association with poor LBP scores at 1 year (beta = 0.28, P < 0.0001).

Conclusion. Posterior decompression relieves LBP as well as leg pain. Long-lasting LBP and concurrent symptomatic cervical myelopathy are important predictors for inadequate LBP relief. There were no reliable imaging parameters predictive of inadequate LBP relief.

Level of Evidence: 4

Introduction

Lumbar spinal stenosis (LSS) is typically characterized by leg symptoms, but the clinical presentations frequently include low back pain (LBP). For patients who are refractory to conservative care, surgery is occasionally indicated. The most frequently performed procedure is posterior decompression, with the primary aim of relieving leg symptoms. Although LBP also often decreases after surgery,[1,2] decompression is generally thought to yield worse results for LBP than for leg pain and is suggested for patients with leg predominant symptoms.[3] However, some studies have reported similar improvements in pain scores between LBP and leg pain.[4–7] To include LBP in therapeutic targets or to take measures to prevent inadequate LBP relief, reliable predictors for LBP relief should be identified. Knowledge of the predictors might aid surgeons in choosing optimal treatments for each patient. Several factors have been shown to be associated with inadequate LBP relief, including narcotic usage,[8] compensation claims,[8] high degrees of apical vertebral rotation,[9] and high Cobb angles.[10] However, many other factors still remain to be studied. The purposes of this study were to confirm whether decompression for LSS relieves LBP as adequately as it relieves leg pain and to identify predictors for inadequate LBP relief. Demographic, clinical, and imaging parameters, including those related to the cervical spine, were evaluated using numeric rating scales (NRSs) for symptoms at 1 and 4 years.

processing....