Uniplanar Cannulated Pedicle Screws in the Correction of Lenke Type 1 Adolescent Idiopathic Scoliosis

Abstract

To report the clinical use of uniplanar cannulated pedicle screws for the correction of Lenke type 1 adolescent idiopathic scoliosis (AIS), and to evalute its safety and clinical outcomes. A total of 68 patients with Lenke type 1 AIS were retrospective analyzed, among which 38 patients were treated with uniplanar cannulated screws at the concave side of periapical levels and multiaxial screws at the other levels (group A). The remaining 30 patients were treated with all multiaxial screws (group B). The preoperative and postoperative radiographic parameters, axial vertebral rotation, and the safety of the pedicle screws were evaluated. Preoperative data were comparable between the 2 groups. The postoperative proximal thoracic curve, main thoracic curve, thoracolumbar/lumbar curve, and apical vertebral rotation were significantly improved in both groups (P < 0.05). The coronal correction rates in group A and B were 83% and 81.9% (P= 0.723). The derotation rates in group A and B were 60.8% and 43.2% (P < 0.05). The rotation classification in the group A was also better than group B. The misplacement rate in group A and B was 7.9% and 11.8% (P < 0.05), and the total misplacement rate on the concave side (11.4%) was higher than that of convex side (8.4%). On the concave side, the misplacement rate in group A and B was 9.7% and 12.3%. On the convex side, the misplacement rate in group A and B was 5.9% and 11.1% (P < 0.05). Collectively, uniplanar cannulated pedicle screws could effectively increase the accuracy of pedicle screws and facilitate the derotation of the apical vertebra compared with the multiaxial pedicle screws.