S1 vertebral bone quality score independently predicts pedicle screw loosening following surgery in patients with adult degenerative scoliosis

MRI-based vertebral bone quality (VBQ) score is an effective predictor of pedicle screw loosening after lumbar fusion surgery and has been recognized as a valuable tool for assessing preoperative bone quality. Due to the lateral curvature of lumbar spine of degenerative scoliosis, accurate measurement of VBQ score by conventional measurement methods that capture MRI signal intensity at L1-4 may be limited under certain conditions. To this end, a new simplified S1 VBQ score method has been proposed, which is comparable to the previous L1-4 VBQ score or S1 Hounsfield unit (HU) value, and has high accuracy and reliability.