后路椎弓根螺钉系统矫正青少年特发性脊柱侧凸术后主动脉位置变化分析

The changes of relative position of the aorta after posterior instrumentation in adolescent idiopathic thoracic scoliosis

中文关键词:  青少年特发性脊柱侧凸  主动脉  椎弓根  螺钉  位置

英文关键词:Adolescent idiopathic scoliosis  Aorta  Pedicle screw  Position

中文摘要:

  【摘要】 目的：评价接受后路椎弓根螺钉系统矫正手术的青少年特发性脊柱侧凸患者术前、术后1周和术后2年主动脉相对于脊柱的空间位置变化。方法：研究对象为接受后路椎弓根螺钉系统矫正手术的22例右胸主弯的青少年特发性脊柱侧凸患者。通过三维重建CT测量患者术前、术后1周、术后2年主动脉位置和顶椎旋转畸形情况，测量参数包括主动脉-椎体距离、主动脉-椎体角、主动脉-椎管距离、左侧椎弓根螺钉长度和顶椎旋转角。通过X线片测量胸主弯的Cobb角和胸椎后凸角。结果：术前主胸弯Cobb角为57.5°±9.8°，术后1周矫正至13.6°±6.5°，术后2年时为16.2°±6.8°；主胸弯Cobb角矫正率术后1周时为77.5%，术后2年时为73.3%。术前顶椎轴面旋转角为29.4°±9.3°，术后1周矫正至14.6°±6.9°，术后2年时为17.4°±6.8°；顶椎旋转畸形的矫正率术后1周时为49.5%，术后2年时为39.7%。主动脉-椎体距离在T6～T11节段术前显著大于术后1周（P<0.05）；在T7～T9节段术后2年显著大于术后1周（P<0.05）。主动脉-椎体角在T5～T11节段术前显著大于术后1周（P<0.05）；在T7～T10节段术后2年显著大于术后1周（P<0.05）。主动脉-椎管距离在T7～T11节段术前显著小于术后1周（P<0.05）；在T6～T10节段术后2年显著小于术后1周（P<0.05）。结论：右胸主弯的青少年特发性脊柱侧凸患者中，术后主动脉相对于脊柱的位置较术前向前内侧移位，术后2年较术后向后外侧移位。在使用椎弓根螺钉系统治疗特发性脊柱侧凸的手术中应该避免椎弓根螺钉穿出椎体前皮质或者椎弓根外侧皮质而导致主动脉损伤。

英文摘要:

  【Abstract】 Objectives: To evaluate the relative spatial position between the aorta and the vertebral body in pre-operation, one-week post-operation and 2 years post-operation in adolescent idiopathic thoracic scoliosis (AIS). Methods: All 22 AIS patients with right-sided major thoracic curve who received posterior correction and instrumentation with pedicle screw construct were included in this study. The position of the aorta and the apical vertebral rotational deformity was evaluated by the measurement of the following parameters in three-dimensional reconstructed CT: aorta-vertebral distance, aorta-vertebral angle, aorta-spinal canal distance, left pedicle screw length and the apical vertebral axial rotational angle (AVR). Cobb angle and thoracic kyphosis were measured in the X-ray film. Results: The mean Cobb angle was corrected from 57.5°±9.8° to 13.6°±6.5° after surgery and settled at 16.2°±6.8° at 2 years follow-up. The correction rate of the major thoracic curve was 77.5% after operation and 73.3% in 2 years follow-up. AVR was also corrected from 29.4°±9.3° to 14.6°±6.9° after surgery. The figure rebounded slightly to 17.4°±6.8° at 2 years follow-up with a correction rate of 49.5% after surgery and 39.7% at 2 years follow-up. For the region between T6 and T11, the measured aorta-vertebral distances were significantly longer as compared to one week after surgery. Correspondingly, the distances measured from T7-T9 segment at 2 years follow-up were also significantly longer than those measured one week after surgery(P<0.05). As far as the aorta-vertebral angle is concerned, the measurements taken from T5-T11 segment prior to surgery were significantly greater than those taken one week afterward. For T7-T10 segment, the aorta-vertebral angles measured at 2 years follow-up were significantly higher than one week after surgery(P<0.05). With regard to the aorta-spinal canal distances, the pre-operational values of T7-T11 segment, were significantly shorter than those one week after surgery. For T6-T10 segment, the aorta-spinal canal distances at 2 years follow-up were significantly shorter in comparison to the earlier measurements taken one week after surgery(P<0.05). Conclusions: In right-sided major thoracic curve AIS patients, the aorta moved anteromedially relative to the spine after posterior correction and instrumentation, while in the 2 years follow-up, the aorta moved posterolaterally. In the treatment of AIS with posterior pedicle screw construct, it was essential to evade the penetration of anterior vertebral cortex or pedicle later cortex by pedicle screw which may cause aorta injury.