Seki Shoji, Yahara Yasuhito, Makino Hiroto, Kobayashi Kenji, Nakano Masato, Hirano Norikazu, Watanabe Kei, Takahashi Jun, Kawaguchi Yoshiharu, Kimura Tomoatsu
Department of Orthopaedic Surgery, Faculty of Medicine, University of Toyama, Toyama, 930-0194, Japan.
Department of Orthopaedic Surgery, Faculty of Medicine, University of Toyama, Toyama, 930-0194, Japan.
J Orthop Sci. 2019 Sep;24(5):780-786. doi: 10.1016/j.jos.2019.01.001. Epub 2019 Jan 23.
Differential rod contouring (DRC) is useful for periapical vertebral derotation and decreasing rib hump in patients with thoracic adolescent idiopathic scoliosis (AIS). However, it is unknown whether DRC in the thoracolumbar/lumbar spine also contributes to derotation. We assessed the contributions of rod contouring and of DRC to the reduction of apical axial vertebral body rotation in patients with AIS with thoracolumbar/lumbar curvatures.
Forty-five (Lenke type 3 or 4, 17; Lenke type 5 or 6, 28) were analyzed for the contribution of DRC to thoracolumbar/lumbar spinal derotation. Rod contouring was assessed by comparing the preinsertion x-ray with the post-operative CT images. Intraoperative C-arm fluoroscopic scans of the periapical vertebrae of the thoracolumbar/lumbar curve of the scoliosis (135 vertebrae) were taken post-rod rotation (RR) and post-DRC in all patients. Three-dimensional images were automatically reconstructed from the taken x-ray images. The angle of vertebral body rotation in these apical vertebrae was measured, and the contribution of DRC to apical vertebral body derotation and rib hump index (RHi) for lumbar prominence was analyzed.
The pre-implantation convex rod curvatures of both Lenke 3/4 and 5/6 groups decreased after surgery. The mean further reductions in vertebral rotation with post-RR DRC were 3.7° for Lenke 3/4 and 4.4° for Lenke 5/6 (P < 0.01). Both changes in apical vertebral rotation and in RHi for evaluating lumbar prominence were significantly correlated with the difference between concave and convex rod curvature in preimplantation. Vertebral derotation was significantly higher in curves with a difference >20° (P < 0.05).
DRC following rod rotation contributed substantial additional benefit to reducing vertebral rotation and decreasing lumbar prominence in thoracolumbar/lumbar scoliosis.
差异棒材塑形（DRC）对于胸椎青少年特发性脊柱侧凸（AIS）患者的根尖椎体去旋转和减少肋骨隆突很有用。然而，胸腰段/腰椎的DRC是否也有助于去旋转尚不清楚。我们评估了棒材塑形和DRC对胸腰段/腰椎弯曲的AIS患者根尖轴向椎体旋转减少的贡献。
分析了45例患者（Lenke 3型或4型，17例；Lenke 5型或6型，28例）DRC对胸腰段/腰椎脊柱去旋转的贡献。通过将植入前X线与术后CT图像进行比较来评估棒材塑形。在所有患者中，在棒材旋转（RR）后和DRC后对脊柱侧凸胸腰段/腰椎曲线的根尖椎体进行术中C形臂荧光透视扫描（135个椎体）。从拍摄的X线图像自动重建三维图像。测量这些根尖椎体的椎体旋转角度，并分析DRC对根尖椎体去旋转和腰椎突出的肋骨隆突指数（RHi）的贡献。
Lenke 3/4组和5/6组植入前凸侧棒材曲率术后均降低。RR后DRC椎体旋转的平均进一步减少量，Lenke 3/4组为3.7°，Lenke 5/6组为4.4°（P < 0.01）。根尖椎体旋转和用于评估腰椎突出的RHi的变化均与植入前凹侧和凸侧棒材曲率的差异显著相关。差异>20°的曲线中椎体去旋转显著更高（P < 0.05）。
棒材旋转后的DRC对减少胸腰段/腰椎脊柱侧凸的椎体旋转和降低腰椎突出有显著的额外益处。
