踝关节骨折手术治疗中后踝螺钉固定异常的表现

Improper screw fixation in the treatment of posterior malleolar fractures

目的总结在踝关节骨折手术治疗中后踝螺钉固定时位置异常的发生情况。方法回顾性分析20l1年1月1日至12月31日收治的417例（421侧）踝关节骨折患者的临床资料，男217例219侧，女200例202侧；年龄14～85岁，平均41岁；右侧223例，左侧198例。术前进行CT检查的368侧骨折中有后踝骨折299侧，其中实际采用螺钉固定的后踝骨折有131侧。分析后踝骨折患者术后X线片和CT扫描图像等影像学资料，观察后踝螺钉固定位置异常的影像学表现。结果螺钉位置异常的CT图像表现为螺钉头和杆部进入下胫腓间隙内，X线片表现为螺钉头位于胫骨腓骨切迹后侧缘的外侧。在131侧采用螺钉固定的后踝骨折中，通过CT检查和X线片检查所发现的后踝螺钉固定位置异常分别为7侧和6侧（9．9％，13／131），其中9侧（69．2％，9／13）为经皮固定。结论手术固定后踝骨折存在螺钉固定位置不良的可能性，术中透视确认螺钉头位于胫骨后结节的胫骨侧可能有助于减少其发生。

Objective To explore the problem of improper screw fixation in the treatment of posterior malleolar fractures. Methods We performed a retrospective analysis of the X-ray films and CT scans of the 421 ankle fractures in 417 patients that had been treated in our department from 1 January 2011 through 31 December 2011. 219 fractures occurred in 217 male patients and 202 fractures in 200 females. Their ages ranged from 14 to 85 years, averaging 41 years. 223 fractures were at the right side and 198 fractures at the left side. Among the 368 ankle fractures that had been examined by CT scan, there were 299 posterior malleolar fractures, 131 of which were fixated by screws. Improper screw fixations of the posterior malleolar fragments were identified and characterized. Results The improper screw fixation was manifested as intrusion of the screw head and shaft into the interspace of distal tibiofibular syndesmosis in the CT scans and as location of the screw head at the lateral side of the posterior margin of the tibiofibular notch in the X-ray films. In the 131 posterior malleolar fractures that had screw fixation, CT confirmed 7 cases of improper screw fixation and X-ray examination 6 cases, giving a rate of improper screw fixation of 9.9% （ 13 / 131 ）. Of the 13 cases 9 belonged to percutaneous fixation （69.2%, 9/13）. Conclusion Although improper screw fixation may likely occur in the treatment of posterior malleolar fractures, it can be reduced by careful fluoroscopy to ensure that the screw is positioned at the tibial side of the posterior tubercle of the tibia.