Abstract
BACKGROUND: Despite its clinical importance, osteoporosis remains underdiagnosed, particularly in spinal surgery patients, where bone quality affects surgical outcomes. Existing screening methods are often costly or inaccessible, highlighting the need for a simpler alternative. OBJECTIVE: The purpose of the present study was to assess the canal bone ratio (CBR) as a predictive tool for bone mineral density (BMD) in patients with lumbar degenerative diseases and establish a specific cutoff value for diagnosing osteoporosis. METHODS: A retrospective analysis was conducted of 102 patients older than 50 years who underwent lumbar spine surgery at our institution from 2016 to 2024. Eligible patients underwent dual-energy x-ray absorptiometry (DXA), full-spine x-ray imaging, and computed tomography within 3 months before their surgery. CBR measurements were obtained by analyzing x-ray images for the inner and outer diameters of the femoral shaft 7 cm below the lesser trochanter. The Youden index based on T score thresholds from DXA scans determined the optimal cutoff value for diagnosing osteoporosis using CBR. RESULTS: The cutoff value for CBR was 0.501, which was identified by analyzing BMD data from the lumbar spine and femoral neck regions. This cutoff demonstrated a strong correlation with low BMD scores, exhibiting a sensitivity of 0.656 and a specificity of 0.671 for identifying osteoporosis among the included patients. Additionally, CBR values negatively correlated with T scores and computed tomography-based Hounsfield units values obtained from lumbar and femoral regions, reinforcing its validity as a screening tool. CONCLUSION: CBR correlates with T scores from DXA and Hounsfield units values, establishing itself as a feasible and practical screening tool for osteoporosis in patients with lumbar degenerative disease. CLINICAL RELEVANCE: CBR facilitates early intervention and improves management in populations at high risk for bone fragility.