X线与CT评估椎管内骨折块间接复位的对比研究

目的 对比研究X线透视椎体标准侧位像上椎体后壁"一线影"与CT扫描对判断椎管内骨折块复位的价值,为术中X线透视即刻判断骨折块间接复位的程度提供依据. 方法 回顾性分析25例胸腰椎爆裂骨折患者的临床资料.术前CT证实均为爆裂骨折,骨块占椎管中矢径比例平均35.2%.所有患者采用短节段椎弓根螺钉系统间接复位,未行椎板切除减压.术中X线透视标准侧位像上骨折椎体后壁呈现连续、平滑的"一线影"时,即认为骨块已复位.术后均行CT扫描观察骨块复位情况. 结果 术后CT示骨折块占椎管中矢径比例由术前35.2%减少至8.6%,术前、术后相比差异有统计学意义(t=9.122,P<0.01),达到椎管有效减压的要求.随访时25例患者的神经功能均正常. 结论 标准侧位像上椎体后壁连续、平滑的.一线影"可作为判断椎管内骨折块复位的一种简单有效的方法,能为术中决定是否行椎板切除减压和骨块推顶提供有效的依据.

Comparison of X-ray and CT in evaluating indirect reduction of spinal canal bone fragment

Objective To compare the value of "linear shadow" of posterior vertebral body wall under standard lateral X-ray fluoroscopy and CT scan in evaluating the reduction of bone fragment retro-pulsed into the spinal canal so as to provide evidence for indirect reduction degree of bone fragment under X-ray fluoroscopy during operation. Methods A retrospective study was done on 25 cases of thoraco-lumbar burst fractures treated at our department. There were 15 males and 10 females, at age range of 24-66 yeas(average 44. 9 years). Preoperative CT scan confirmed burst fractures in all cases. Bone frag-ment occupied mearl 35. 2% of midsngittal diameter of injured segment. All cases were treated by indirect reduction with short-sesment pedicle instrumentation, rather than laminotomy or partial laminectomies. When imging of posterior vertebral body wall manifested a continuous and smooth"linear shadow" under standard lateral X-ray fluoroscopy during operation, bone fragment War considered to be under reduction. CT span was performed to evaluate the reduction of bone fragment postoperatively. Results The bone fragment occupation of midsngittal diameter of injured segment was decreased from preoperative 35. 2%to postoperative 8. 6%, with statistical difference(t=9. 122, P<0. 01). Neurological function of all 25 cases was normal at last follow-up. The decompression of spinal canal was effective. Conclusions A continuous and smooth"linear shadow"on posterior vertebral body wall imaging is a simple and effective way to judge the reduction of bone fragment retropulsed into the spinal canal and can provide evidence for whether laminotomies and pushing bone fragment are necessary during operation.