Surgical treatment of progressive or severe adolescent idiopathic scoliosis (AIS) often consists of posterior spinal fusion. There is still no consensus on the preferred instrumentation technique. Based on low level evidence thoracic pedicle screws seems to give a better correction of coronal Cobb angle and vertebral rotation, and to have a higher pull-out strength. We hypothesize that proximal fixation of the spondylodesis with a pedicle screw construct gives better coronal Cobb angle correction with less loss of correction compared to a hook claw construct.
The main objective is to compare the coronal Cobb angle correction of proximal hook claw fixation versus proximal pedicle screw fixation after two years of follow-up. The secondary objectives of the study are: comparison of coronal Cobb angle correction direct postoperatively, coronal Cobb angle correction loss after two years, vertebral rotation correction, complication and revision rate, pulmonary function, postoperative lung volume, cosmetic outcomes, and subjective questionnaire results in proximal hook claw versus screw fixation, assessment of the correlation between the extent of scoliosis correction and the degree of patient satisfaction, determination of the accuracy rate of thoracic pedicle screw placement, and to get insight in the natural course of serum cobalt and chromium levels in a cohort of adolescent idiopathic scoliosis patients undergoing posterior spinal fusion.