不同椎弓根骨折类型行伤椎置钉的CT影像学观察

Observation of computed tomography images of placing screws in the injured vertebra for different types of pedicle fractures

目的通过CT观察不同椎弓根骨折类型的置钉情况来探讨经伤椎置钉治疗胸腰椎骨折的安全性。方法选取我院2008年6月至2011年6月胸腰椎单节段骨折共56例,全部患者均采用经伤椎椎弓根置钉的后路复位内固定手术方式。术前常规行标准胸腰段DR摄片和CT扫描,运用PACS系统保存伤椎椎弓根层面的相关图像。观察伤椎椎弓根的完整性和骨折部位,并对其进行骨折分型;术后CT扫描观察伤椎椎弓根置钉情况,用Youkilis标准来评价置钉的准确率。结果椎弓根骨折类型主要分为椎弓根与椎体结合处骨折、椎弓根腰部骨折、椎弓根与椎板结合处骨折三型;56例经伤椎椎弓根置钉共105枚,其中左侧椎弓根置钉57枚,右侧置钉48枚,在伤椎单侧椎弓根置钉者7例。术后CT影像发现:在伤椎椎弓根置入的105枚螺钉中,有98枚螺钉完全位于椎弓根骨皮质内,7枚螺钉位置出现偏差,但均未导致相应临床症状。螺钉位置按Youkilis分级:Ⅰ度98枚,Ⅱ度7枚,Ⅲ度0枚,本组病例没有发现螺钉向椎体的上方和前方穿出。术后发生脑脊液漏1例,没有切口感染、医源性的脊髓神经功能障碍加重等并发症。末次随访时有2例发生内固定失败(钉棒松动和断裂各1例)。结论术前掌握好伤椎置钉的适应证并根据CT制定个体化的手术计划,术中把握好进钉点、方向和螺钉大小及长度等因素,经伤椎椎弓根置钉是安全和可行的,不增加并发症,是临床上治疗胸腰椎骨折的一种可靠方法。

Objective To investigate the safety of the treatment of thoracolumbar fractures by placing screws in the injured vertebra through observing the screw placement for different types of pedicle fractures based on the Computed Tomography （ CT ） images. Methods 56 patients with single-segment thoracolumbar fractures underwent the treatment of posterior internal fixation with screws placed in the injured vertebra from June 2008 to June 2011 in our hospital. Preoperatively the standard Digital Radiography （ DR ） and CT were performed routinely in all the patients. Relevant images of the injured pedicles were kept by the picture archiving and communication system （ PACS ）. The integrity and position of the fractured pedicles were observed, and the types of fractures were classified. Postoperatively the placed screws were observed based on the CT images. The Youkilis standard was used to evaluate the accuracy ofpedicle screws. Results Pedicle fractures were divided into 3 main types, including fractures of the junction of pedicle and vertebra, pedicle waist fractures and fractures of the junction of pedicle and lamina. 105 pedicle screws were placed in 56 patients, with 57 screws at the left side and 48 screws at the fight side. Unilateral pedicle screws were used in 7 patients. The postoperative CT images showed 98 screws were placed in the bone cortex completely and 7 screws were deviated, without any relevant clinical symptoms. The screw position was graded by the Youkilis standard, including I degree in 98 cases, II degree in 7 cases, III degree in 0 case. In this group, such screws to be above or in front of the vertebral body were not found. 1 patient had cerebrospinal fluid leakage postoperatively, but no complications such as incision infection or the exacerbation of iatrogenic spinal cord dysfunction occurred. The failure of internal fixation was noticed in 2 cases in the latest follow-up （ screw loosening and breakage in 1 case respectively ）. Conclusions The placement of screws in the injured vertebra is a safe, feasible and reliable method in the clinical treatment of thoracolumbar fractures, with the complications not increased. However, the indications of placing pedicle screws should be mastered preoperatively, and the nail point and direction and the screw size and length should be grasped during the surgery, with the individualized surgical plan made based on the CT images.