应用椎板开窗法置入胸椎椎弓根螺钉的精确性和安全性评估

The assessment of accuracy and safety of thoracic pedicle screws placement with interlaminar fenestration technique in severe kyphoscoliosis treatment

目的分析应用椎板开窗法行胸椎椎弓根螺钉置入治疗重度脊柱侧后凸患者的精确性和安全性。方法1996年6月至2007年12月，应用椎板开窗法行胸椎椎弓根螺钉置入治疗23例重度脊柱侧后凸患者（A组），其中男性9例，女性14例；年龄13—23岁，平均17．8岁；术前主胸弯冠状面Cobb角平均97．3°，平均后凸角67．4°。作为对照，同期应用非开放法置钉治疗重度脊柱侧后凸患者22例（B组），其中男性7例，女性15例；年龄14—21岁，平均17．2岁；术前主胸弯冠状面Cobb角平均为96．6°，平均后凸角62．1°。两组患者术后均行CT扫描，统计螺钉置入并发症，对螺钉穿透椎弓根皮质骨的CT扫描图像进行联机测量并统计分析。结果A组和B组各置入胸椎椎弓根螺钉209和201枚，术中发生椎弓根骨折5例和16例，发生硬膜撕裂4例和7例，螺钉错置18枚和45枚。B组螺钉错置率高于A组，差异具有统计学意义（P〈0．05）。A组上、中胸椎与下胸椎之间、凸侧与凹侧之间，螺钉错置率差异均具有统计学意义（P〈0．05）。两组均无脊髓及大血管损伤。A和B组经平均3．2年、3．4年随访，术后冠状面和矢状面平均矫正度未见明显丢失。结论重度脊柱侧后凸胸椎椎弓根螺钉置入技术难度较高，应用椎板开窗法可有效增加螺钉置入精确性和安全性。

Objective To analyze the accuracy and safety of thoracic pedicle screws placement with interlaminar fenestration technique in severe kyphoscoliosis treatment. Methods Twenty-three cases of severe kyphoscoliosis between June 1996 and December 2007 underwent pedicle screw placement of thoracic vertebrae by interlaminar fenestration technique. Postoperative CT scan was performed in all cases; there were 9 males and 14 females with the averaging age 17.8 years old. The preoperative Cobb angle of the main thoracic curve was 97.3° in average. The average kyphotic angle in main curve was 67. 4°. Patients who underwent screw placement by closing technique and postoperative CT scan in the same stage with severe kyphoscoliosis were selected as control group （B） ： there were 22 patients with the averaging age 17. 2 years old. The preoperative Cobb angle of the main thoracic curve was 96. 6° in average. The average kyphotic angle in main curve was 62. 1°. The screw-related complications were analyzed and online measure and analyze the degree of screw penetration according to CT by statistics. Results There were 209 thoracic pedicle screws being inserted in group A, no spinal cord and large blood vessel injury occurred, 5 patients occurred intraoperative pedicle fracture, dura lesion had 4 patients. Screws misplacement ratio was 8. 6% , there were 11 screws located in the thoracic pediele laterally, 6 screws located in medially, 1 screw presented a moderate anterior cortical perforation. The number of screws misplacement in upper and mild thoracic vertebrae were 15, occupied 83.3% ; the number of screws misplacement in lower thoracic vertebrae were 3, occupied 16. 7%. There was statistics difference （P 〈 0. 05）. Of the total 116 thoracic pedicle screws inserted on the convex side, the ratio of screw misplacement was 5.2% ; 93 screws on the concave side, the ratio of screw misplacement was 12. 9% , there was statistics difference （ P 〈 0. 05 ）. There were 201 thoracic pedicle screws being inserted in group B, no spinal cord and large blood vessel injury occurred,16 patients occurred intraoperative pedicle fracture, dura lesion had 7 patients. The ratio of screw misplacement was 22. 4% , there were 24 screws located in the thoracic pedicle laterally, 11 screws located in medially, 10 screw presented a moderate anterior cortical perforation. The ratio of screw misplacement in Group B was higher than Group A （P 〈 0. 05）. All cases received 3.2 years and 3.4 years follow-up. There was no obvious loss of correction in coronal and saggital plane at the latest follow-up. Conclusions It is technically demanding for placement of thoracic screw in the severe kyphoscoliosis treatment. The interlaminar fenestration technique can increase the accuracy and safety of thoracic pedicle screw placement.