不同Risser征的胸弯青少年特发性脊柱侧凸前路矫形术后矢状面重建

The influence of the Risser sign on the post-operative sagittal profile of idiopathic thoracic scoliosis patients treated with the anterior instrumentation

目的探讨不同Risser征的胸弯青少年特发性脊柱侧凸（adolescent idiopathic scoliosis，AIS）行前路矫形术后胸椎及远端腰椎矢状面的重建模式。方法分析2002年6月至2006年11月行胸弯前路矫形内固定术且有2年完整随访资料的Lenkel型AIS患者43例，男3例，女40例；年龄11～18岁，平均（14．1±1．7）岁；胸弯Cobb角39°-65°，平均46．0°±7．5°。按照患者Risser征评分分为：A组（Risser0）、B组（Risser1-3）和C组（Risser4-5）。分别测量这三组患者术前及术后历次随访时的胸弯Cobb角、腰弯Cobb角、胸椎后凸角、腰椎前凸角、内固定远端交界性后凸角、胸腰椎交界性后凸及骶骨后上缘与C7铅垂线的距离。结果三组患者均获得随访，随访时间24～60个月，平均27．4个月。末次随访时，A组胸腰椎交界性后凸角为6．6°，较术前的-1．7°增大8-3°；B组为0．6°，较术前的-7-3°增大7．9°；C组术后历次随访与术前均无显著性差异。三组患者胸椎后凸角分别为21．2°、18．4°和14．7°，胸椎后凸角历次随访时的变化无统计学差异。三组患者的内固定远端交界性后凸角均表现为前凸丢失，后凸增大。结论低Risser征的Lenke1型AIS患者行前路矫形内固定术后胸椎后凸角及胸腰椎交界性后凸增加，可能与胸椎后份生长后矢状面重建引起的胸腰椎交界区失代偿有关。

Objective To analyze the influence of the Risser sign on the sagittal compensatory mode of the spine in idiopathic thoracic scoliosis after anterior spinal fusion. Methods Between June 2002 and November 2006, 43 adolescent idiopathic scoliosis （AIS） patients （Lenke 1） undergone anterior correction with a minimum 2 years follow-up were included in this study. The patients were divided into three groups according to the Risser sign： group A （Risser 0）, group B （Risser 1-3）, and group C （Risser 4-5）. The preoperative, postoperative and follow-up sagittal profile were evaluated by the following radiological parameters measured on the lateral radiograph, including the thoracic kyphosis, the lumbar lordosis, the thoracolumbar junction kyphosis, the distal junctional kyphosis, and the sagittal vertical axis. Results In group A, the thoracolumbar junction kyphosis significantly changed from -1.7° preoperative to 6.6° at the final follow-up, with an average increase of 8.3°. Similarly, in group B, the thoracolumbar junction kyphosis changed from -7.3° before surgery to 0.6° at the final follow-up, with an average variation of 7.9°. No obvious change of the thoracolumbar junetion kyphosis was observed in group C. At the final follow-up, the average thoracic kyphosis in three groups was 21.2°, 18.4° and 14.7°, respectively. No significance of the variation of the tho- racie kyphosis was observed in the three groups, however, in group A and B, the thoracie kyphosis showed an ascending trend during the follow-up without significant statistieal differenee, in addition; the ratio of the thoracic kyphosis increased in group A was higher eompared with group B and C. Conclusion For AIS patients with low Risser sign, the increased thoraeie kyphosis, and the thoracolumbar junction kyphosis may be aseribed to the decompensation of thoraeolumbar region caused by the reeonstruetion of sagittal alignment due to the continued growth of posterior elements of the thoracic spine.