Abstract
Study Aims: This study’s objectives were to measure pre-operative and postoperative axial vertebral rotational deformity at the curve apex in endoscopically-treated anterior-instrumented scoliosis patients using CT, and assess the relevance of these findings to clinically measured chest wall rib hump deformity correction.
Introduction: Thoracoscopic instrumented anterior spinal fusion for adolescent idiopathic scoliosis (AIS) has clinical benefits that include reduced pulmonary morbidity, postoperative pain, and improved cosmesis. However, quantitative data on radiological improvement of vertebral rotation using this method is lacking.
Methods: Between November 2002 and August 2005, 20 AIS patients with right-sided thoracic major curves underwent endoscopic single-rod anterior fusion. Preoperative and two-year postoperative CT was performed to assess axial vertebral rotation at the curve apex. Correlation between apical vertebral rotation measured on CT and rib hump measured using a scoliometer was assessed.
Results: The mean angle of correction achieved in axial vertebral body derotation at the apical vertebra measured by CT was 7.9° and equated to 43% improvement. Preoperative and postoperative rib hump deformity correction correlated significantly with CT measurements using regression analysis (p=0.03). The mean improvement in rib hump deformity was 55%. Conclusion: We believe this is the first quantitative CT study to confirm that endoscopic anterior instrumented fusion for AIS substantially improves axial vertebral body rotational deformity at the apex of the curve. The margin of correction of 43% compares favourably with historically published figures of 24% for patients with posterior all-hook-rod constructs. CT measurements correlated significantly to the clinical outcome of rib hump deformity correction.
Ethics: local committee approval
Statement of Interest: none
Correspondence should be addressed to BSS c/o BOA, at the Royal College of Surgeons, 35–43 Lincoln’s Inn Fields, London, WC2A 3PE, England.
