Assessment of Curve Flexibility in Idiopathic Scoliosis Patients With Severe Scoliosis (Cobb Angle ≥ 90 o ): Comparison Between the Supine Traction Radiograph Versus the Physician Supervised Supine S
Chris Yin Wei Chan, Josephine Rebecca Chandren, Evonne Yee Wern Tan, Saturveithan Chandirasegaran, Chee Kidd Chiu, Mun Keong KwanStudy design
Retrospective study.
Objective
To analyze the flexibility of severe scoliosis with cobb angle ≥90 o , comparing between the supine traction radiograph versus the physician supervised supine side bending film.
Methods
72 severe idiopathic scoliosis patients between 2015 to 2023 in a single academic institution who underwent single-staged posterior spinal fusion with curves more than ≥90 o with available anteroposterior, traction and side bending radiographs were recruited.
Results
58 patients had severe curves in the main thoracic (MT) region, with mean preoperative Cobb angle of 107.3±16.6° and postoperative Cobb angle of 51.2±15.5°. 18 patients had severe curves at thoracolumbar/lumbar (TL/L) region, with mean preoperative Cobb angle of 99.8±8.2° and postoperative Cobb angle of 45.2±12.8°. The correction rates for MT and TL/L curve is 52.7±11.1° and 55.0±11.1° respectively. No significant differences were observed between sidebending (SB) and traction radiographs in assessing MT curve flexibility (34.7±12.4% vs. 34.5±11.8%, respectively; p=0.907) or in the corresponding correction indices (1.7±0.5 vs. 1.7±0.9, respectively; p=0.461). However, TL/L curves had a significant difference in flexibility comparing SB (46.0±12.6%) and traction radiographs (42.0±11.5%) (p=0.008) and comparing the side bending correction index (SBCI) (1.2±0.2) and traction correction index (TCI) (1.4±0.3) (p=0.010). The SBCI for TL/L curve was closer to 1, indicating that the Cobb angle on SB radiographs for TL/L curves could more accurately predict the postoperative Cobb angle.
Conclusion
In severe TL/L curves, physician-supervised supine side bending (PSSB) radiographs may provide a more accurate assessment of curve flexibility, as reflected by a correction index closer to 1. These findings suggest that PSSB radiographs may be a useful radiographic assessment for evaluating TL/L curve flexibility and guide preoperative planning in patients with severe idiopathic scoliosis.