Director of Spine Center Bumin Hospital Seoul, Seoul-t'ukpyolsi, Republic of Korea
Introduction: Although Lumbar Foraminal Stenosis (LFS) is one of the most important pathologies of severe and prominent radiculopathy, it is often missed by clinicians in comparison to definite herniated disc disease or central spinal stenosis.
Objectives: Hence is important to have a comprehensive, accurate and objective grading system to describe the LFS.
Methods: A retrospective observational study of 100 patients, who were suffering from unilateral LFS at L4–L5 level and underwent surgery from oct-2014 to oct-2018 was done. Two bony structures (the superior articular process (SAP) and posterior spur (PS) of the vertebra) and two soft tissue structures (the ligamentum flavum (LF) and foraminal disc (FD)) were considered while grading the foramen. A sagittal MR image cut showing the most stenotic lesion at the L4–L5 index foramen was extracted from each patient. Two experienced spine surgeons analyzed the view using a new grading criterion.
Results: The interobserver reliability between the two observers measured by kappa value was 0.982 for the FD indicating almost a perfect agreement, and 0.847 for the FL, suggesting near perfect agreement. The kappa value was 0.909 for SAP and 0.863 for PS, suggesting near perfect agreement.
Conclusion: The new grading system aims to provide a comprehensive yet practical, objective, and easy-to-apply grading system for LFS, for better surgeon-to-surgeon and radiologist communication. The initial results of interobserver reliability are encouraging. Further studies will be needed to determine its clinical utility and whether this can be used to plan the surgical approach in cases of LFS.
