Multicentre investigation on the effect of decompressive surgery on Balance and physical ActiviTy Levels amongst patients with lumbar Spinal stenosis (B-ATLAS): protocol for a prospective cohort study.

introductionPatients with lumbar spinal stenosis may have poor balance, decreased physical function and problems maintaining physical activity levels due to radiculopathy. Decompressive surgery is often indicated if conservative management fails to achieve a satisfactory clinical outcome. While surgical management has proven effective at treating radiculopathy, and patients report increased physical function postoperatively, objective measures of postural control and physical activity remain sparse. This study aims to investigate the effects of decompressive surgery on postural control and activity levels of elderly patients with lumbar spinal stenosis using objective measurements. METHODS AND ANALYSIS: This is a 24-month, multicentre, prospective cohort study. Patients ≥65 years of age with MRI-verified symptomatic lumbar central canal stenosis will be recruited from two separate inclusion centres, and all participants will undergo decompressive surgery. Preoperative data are collected up to 3 months before surgery, with follow-up data collected at 3, 6, 12 and 24 months postoperatively. Postural control measurements are performed using the Wii Balance Board, mini Balance Evaluation Systems Test and Tandem test, and data concerning physical activity levels are collected using ActiGraph wGT3X-BT accelerometers. Patient-reported outcomes regarding quality-of-life and physical function are collected from the EuroQol-5D, 36-Item Short Form Health Survey and Zurich Claudication Questionnaire. Primary outcomes are the change in the sway area of centre of pressure and total activity counts per day from baseline to follow-up at 24 months. A sample size of 80 participants has been calculated. ETHICS AND DISSEMINATION: The study has been approved by the Regional Ethics Committee of Region Zealand (ID EMN-2022-08110) and the Danish Data Protection Agency (ID REG-100-2022). Written informed consent will be required from all participants before enrolment. All results from the study, whether positive, negative or inconclusive, will be published in international peer-reviewed journals and presented at national and international scientific meetings. Study findings will be further disseminated through national patient associations. TRIAL REGISTRATION NUMBERS: NCT06075862 and NCT06057428.