中国青少年特发性脊柱侧凸患者胸椎椎弓根形态学三维CT分析

Morphometric analysis of thoracic pedicles in Chinese patients with adolescent idiopathic scoliosis： Astudy based on the 3-dimensional CT reconstruction

目的总结中国青少年特发性脊柱侧凸患者胸椎椎弓根形态学特点，与其他人种特发性脊柱侧凸患者胸椎椎弓根形态比较，为手术中胸椎安全置钉提供参考。方法回顾性分析2007年7月至2012年6月期间56例于我院行术前CT扫描三维重建的青少年特发性脊柱侧凸（右胸弯）患者的资料，男10例，女46例；年龄10-18岁，平均14．8岁。Lenke分型：I型28例、Ⅱ型12例、Ⅲ型14例、Ⅳ型2例，，术前主胸弯Cobb角平均为55°（36°-90°）。测量其胸椎两侧椎弓根在欠状面、冠状面、轴面的置钉长度、椎弓根宽度及角度等形态学指标，总结其变化规律，并与文献报道的其他人种数据进行对比。结果主胸弯顶椎区凹侧椎弓根宽度小于凸侧，椎弓根置钉长度大于凸侧，椎仁；根尾倾角度小于凸侧。椎弓根欠状面宽度白头端向尾端逐渐增加，平均值范嗣为0．68～1．36cm；轴面椎弓根宽度平均值范同为0.30-0.70cm。冠状面椎弓根最小径略小于轴面椎弓根宽度，平均值范同为0．28-0．67cm。结论与欧美人种相比，中国特发性脊梓侧凸患者椎弓根宽度较小。顶椎区凹侧置钉难度大、风险高，建议使用直径3．5mm椎弓根螺钉或采用极外侧置钉法。

Objective To investigate morphology of thoracic pedicles of Chinese patients with adolescent idiopathic scoliosis, and to find if the differences exist compared with other races and provide a reference for the pediele screw placement. Methods Data of 56 adolescent idiopathic scoliosis patients who underwent CT scan and 3-dimensional reconstruction in our hospital from July 2007 to June 2012 were retrospectively analyzed. There were 10 males and 46 females, aged from 10 to 18 years （average, 14.8 years）. According to the l,enke classification, there were 28 cases of type I , 12 cases of type Ⅱ, 14 cases of type m and 2 cases of type IV. The average Cobb angle was 55° （range, 36° to 90°） before operation. Based on 3-dimensional CT reconstruction, following parameters were measured： pedicle width and pedicle angle in sagittal plane, minimum pediele diameter in coronal plane, chord length, pedicle width and pedicle angle in transverse plane. After concluding the regular pattern of variation of pedicle morphology, a comparison with other races was conducted. Results Compared with the convex side, the pedicle width and pedicle angle on the concave side of the main thoracic curve were smaller, while the chord length was longer. In sagittal plane, the pedicle width increased from head end to tail end, ranging from 0.68 to 1.36 cm. The pedicle width in transverse plane ranged from 0.30 to 0.70 cm. In coronal plane, the minimum pedicle diameter ranged from 0.28 to 0.67 em. Conclusion Compared with the western patients, the pedicle width is smaller in Chinese patients with adolescent idiopathic： scoliosis. It is difficult and high risk to implant screws on the concave side of the apical vertebra region. So we suggest that pedicle screw with a diameter of 3.5 mm should be used to avoid complications.