INTRODUCTION: Lumbosacral radiculopathy associated with herniation of the nucleus pulposus (HNP) is a common clinical problem associated with delayed recovery, persistent disability and increased healthcare utilization. The reported prevalence of radiating leg pain varies from1% to 40% and has a large financial burden increasing healthcare and economic costs of general low back pain by approximately two thirds. Despite the high prevalence of this condition, its conservative treatment remains challenging for spine specialists and 40-50% of patients will continue to have symptoms for a year or longer. Our study investigates the coronal lumbar spinal alignment as predictor of conservative treatment outcomes in patients with chronic low back pain and radiculopathy due to HNP using a multi-center prospective observational trial with a 6-month follow up. We hypothesize that the magnitude of the lumbo-sacral curve (so-called fractional curve) would be a predictor of success or failure of conservative care outcomes.
METHODS: A multicenter, prospective cohort study conducted in 5 physiotherapy clinics in the UAE from January 2021 to March 2023 to assess coronal lumbar spine radiographic parameters as a predictor of conservative therapy outcomes in patients suffering from low back and leg pain due to lumbar herniated nucleus pulposus (HNP). Ninety patients (mean age 44 yrs., 54% male) with lumbar HNP underwent conservative therapy. All participants received lumbar spine MRI and radiography to assess spine alignment.The Michigan State University (MSU) classification for lumbar disc herniation was used to objectively measure herniated lumbar discs. All lumbar HNP with unilateral or bilateral radicular pain and patients aged between 18 and 65 years old were considered eligible. Interventions included specific exercises, diathermy, traction, education, a home-based exercise program, and medications. Detailed demographic data was collected. Follow-up was 6-months after discharge. A successful outcome was based on a minimum of the following four outcomes: (1) reduction of radicular or leg pain by 17.5 points (0–100 NRS); (2) fatigue reduction by 7.5 points; (3) distress reduction by 5 points; and (4) interference reduction by 9.5 points.
RESULTS: At 6-month follow-up it was found that patient age, education, and radiographic determined lumbosacral angle measures significantly affected the odds of a successful outcome. Increasing age 1-year significantly decreased the odds of success of improving pain, fatigue (OR =0.85, p = 0.016) and interference scores (OR = 0.89, p = 0.042) by 15%, 15%, and 11% respectively. Lower education significantly increased the odds of success for improving pain, fatigue, and interference by 26.18, 26.18, and 7.5 (p = 0.006, = 0.006, and = 0.029 respectively). Increasing (worsening) the radiographic lumbosacral angle by each 1° significantly reduced the odds of success for improving pain, fatigue, distress, and interference by 3.52, 3.52, 27.99, and 2.55, respectively (p < 0.001, < 0.001, = 0.003, = 0.001).
DISCUSSION: In this multicenter study, our findings indicate that younger age, less education, and better coronal radiological lumbar spine alignment all had a substantial impact on the likelihood of success of 6-month outcomes in patients suffering from chronic lower back pain and radiculopathy due to lumbar disc herniation.