摘要目的:探讨桡骨远端骨折掌侧内固定术后背侧关节内骨块移位的危险因素。方法:回顾性分析同济大学附属同济医院创伤骨科自2016年7月至2020年7月采用单纯掌侧钢板内固定治疗的桡骨远端骨折患者资料，使用Mimics 20.0软件对患者术前CT进行三维重建，筛选出伴背侧关节内骨块的患者66例，男31例，女35例；年龄23~78岁，平均53.4岁；桡骨远端AO分型：C1型17例，C2型22例，C3型27例。根据术后第2天及门诊随访X线结果判定背侧关节内骨块的移位情况，13例移位>2 mm为移位组，其余53例为未移位组。比较两组患者的术前一般资料以及背侧骨块的解剖数据（术前总移位距离、横向宽度、纵向宽度、横纵比、高度、体积），分析其与背侧骨块发生移位的关系。结果:两组患者术前一般资料（年龄、性别、患侧、致伤原因、AO分型）比较差异均无统计学意义（ P>0.05），具有可比性。所有患者术后获6~24个月（平均14个月）随访。术后均无神经、血管损伤及感染等并发症发生。移位组患者均未行翻修手术，术后随访骨折均顺利愈合。移位组骨块术前总移位距离为（10.0±1.3）mm，高于未移位组的（7.8±1.5）mm；移位组骨块横向宽度为（8.2±1.3）mm，低于未移位组的（10.8±2.3）mm；移位组骨块横纵比为1.2±0.2，低于未移位组的1.4±0.2；移位组骨块体为（690.5±201.4）mm 3，低于未移位组的（995.8±295.0）mm 3；以上项目两组间比较差异均有统计学意义（ P<0.05)。 结论:桡骨远端骨折背侧关节内骨块的术前总移位距离、横向宽度、横纵比、体积是掌侧内固定术后背侧关节内骨块移位的危险因素。

abstractsObjective:To explore the risk factors that may affect the stabilization of dorsal intra-articular fragment in distal radius fracture after volar internal fixation.Methods:A retrospective analysis was performed of the patients with distal radius fracture who had been treated by volar internal fixation at Department of Traumatic Orthopedics, Tongji Hospital Affiliated to Tongji University from July 2016 to July 2020. After 3D reconstruction of their preoperative CT scans by software Mimics 20.0, 66 patients with a dorsal intra-articular fragment were screened out. They were 31 males and 35 females, aged from 23 to 78 years (average, 53.4 years). By the AO classification, there were 17 case of type C1, 22 cases of type C2, and 27 cases of type C3. The displacement of dorsal intra-articular fragment was judged by X-ray observation on postoperative day 2 and X-ray follow-up at the outpatient department. The 13 patients with displacement of dorsal intra-articular fragment>2 mm were assigned into a displacement group while the other 53 ones into a displacement-free group. The 2 groups were compared in terms of preoperative general data and anatomical data of the dorsal intra-articular fragment (total preoperative displacement, radius-ulnar length, dorsal-volar length, aspect ratio, proximal-distal length and volume) to analyze the correlations between them and displacement.Results:There was no significant difference in preoperative general data (age, gender, affected side, cause of injury or AO classification) between the 2 groups, showing comparability between groups ( P>0.05). All patients were followed up for 6 to 24 months (mean, 14 months) after surgery. There were no postoperative complications like neurovascular lesion or infection. None of the patients in the displacement group underwent revision surgery, and the fractures healed successfully during the postoperative follow-up. The total preoperative displacement in the displacement group was(10.0±1.3) mm, significantly larger than that in the displacement-free group [(7.8±1.5) mm]; the radius-ulnar length in the displacement group was (8.2±1.3) mm, significantly shorter than that in the displacement-free group [(10.8±2.3) mm]; the aspect ratio of the fragment in the displacement group was 1.2±0.2, significantly lower than that in the displacement-free group (1.4±0.2); the fragment volume in the displacement group was (690.5± 201.4) mm 3, significantly smaller than that in the displacement-free group [(995.8±295.0) mm 3]. There were significant differences in the above items between the 2 groups ( P<0.05). Conclusion:The total preoperative displacement, radius-ulnar length, aspect ratio and volume of a dorsal intra-articular fragment are important factors which may affect the displacement of the dorsal fragment after volar internal fixation.