Comparison of X-ray and CT in evaluating indirect reduction of spinal canal bone fragment / 中华创伤杂志

ABSTRACT

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.