Correlation of coefficient of stenosis with clinical symptoms in lumbar spinal stenosis

Introduction: Lumbar spinal stenosis (LSS) is defined as a clinical syndrome of buttock or lower extremity pain, with or without low back pain, resulting from diminished space for neurovascular elements in the spinal canal. It is one of the most common indications for spinal surgery in patients older than 65 years of age. In patients with lumbar spinal stenosis, the relationship between the radiological severity and clinical findings is not clear. The aim of this study was to determine the coefficient of stenosis which is the ratio of total lateral canal cross sectional area to the total dural sac cross sectional area and its correlation between the pain and disability level. Materials and Methods: This is an observational descriptive cross sectional study. A total of 67 patients (33 male and 34 female) with mean age of 66.34±8.62 years (range: 48 to 83 years) with neurogenic claudication and central LSS who presented between February 2021 to August 2023 were included in the study. Dural sac cross sectional area, total lateral canal cross sectional area were noted and the coefficient of stenosis is calculated at the maximum stenotic level in MRI to describe the severity of LSS. This was correlated with the patients disability measured by Oswestry disability Index (ODI) and pain measured by Numeric rating scale (NRS) for back and leg pain and Visual analogue scale (VAS). Conclusion: LSS is a clinicoradiologic syndrome. There is debatable correlation between radiological severity of stenosis and patients’ disability and pain. Therefore coefficient of stenosis could be a valuable parameter to distinguish lumbar spinal stenosis disability from other differential causes of these disability.