TITLE:
Pedicle Screw Insertion for Concave Side of Proximal Thoracic Curve in Adolescent Idiopathic Scoliosis
AUTHORS:
Michio Hongo, Yuji Kasukawa, Akiko Misawa, Daisuke Kudo, Ryota Kimura, Naohisa Miyakoshi
KEYWORDS:
Pedicle Screw, Proximal Thoracic Curve, Adolescent Idiopathic Scoliosis
JOURNAL NAME:
Open Journal of Orthopedics,
Vol.12 No.7,
July
21,
2022
ABSTRACT: Background: Insertion of the pedicle screws (PS) into the proximal thoracic spine is occasionally challenging owing to the small size of the pedicles and the proximity to the spinal cord. An appropriate anchor placement method for the concave side of the proximal thoracic curve has not been established yet. This study aimed to evaluate the pedicle size and position of PS on the concave side of the proximal thoracic curve in patients with adolescent idiopathic scoliosis (AIS). Methods: Forty consecutive patients with AIS who underwent correction and fusion with all PS constructs, including the proximal thoracic curve in the fusion area, were included. After identifying the screws inserted on the concave side of the proximal thoracic curve, the pre-operative morphology and postoperative position of the inserted PS, including the end vertebrae, were analyzed using computed tomography (CT). Screw perforations were categorized into four grades depending on the degree of perforation from the pedicle wall on postoperative CT and were classified using an outcome-based classification. Results: A total of 109 screws were inserted on the concave side of the proximal thoracic curve. The average width of all pedicles was 3.5 ± 1.1 mm. The width of 90 pedicles (83%) was Conclusion: Perforations were found in 84% of the PS on the concave side of the proximal thoracic curve; however, 93% of the PS were considered acceptable in the outcome-based classification. Thus, we conclude that the in-out-in technique may be both feasible and effective.