A comparative study of supine traction, supine side-bending radiographs, and supine MRI to determine coronal flexibility in degenerative lumbar scoliosis patients

Purpose The purpose of this study was to compare curve correction in degenerative lumbar scoliosis using supine traction radiographs, supine side-bending radiographs, and supine MRI. Methods A prospective analysis of Cobb angles from patients diagnosed with degenerative lumbar scoliosis who underwent supine traction radiography (TR), side-bending radiography (SB), and supine MRI. The Cobb angles at thoracic (T), thoracolumbar/lumbar (TL/L), and lumbosacral (LS) levels were measured, and the curve correction in percentages compared with standing AP radiography was calculated as corrective flexibility. Differences in curve correction were analyzed. Results In total, 33 patients with an age range of 50-80 years were eligible for inclusion. Traction radiography provided the greatest accuracy in curve correction, with a significant difference from side-bending radiography and supine MRI in T, TL/L, and LS levels (P < 0.001). The difference between side-bending radiography and supine MRI in TL/L and LS levels was not significant (P = 0.721, P = 0.654, respectively). A moderate correlation was found between the corrective flexibility of TR and SB at the T level (0.563, P = 0.001), a strong correlation was observed between the corrective flexibility of TR and SB at the TL/L level (0.709, P < 0.001), and at the TL/L level, a moderate correlation was identified between TR and supine MRI corrective flexibility (0.425, P = 0.014). Conclusions Traction radiographs significantly outperformed side-bending radiographs and supine MRI in terms of access curve flexibility in degenerative lumbar scoliosis.