尺骨茎突骨折不愈合对下尺桡关节稳定性影响的有限元分析

Finite Element Analysis of the Effect of Ulnar Styloid Fracture Nonunion on the Stability of the Distal Radioulnar Joint

目的运用有限元分析技术,探讨尺骨茎突骨折不愈合对下尺桡关节稳定性的影响。方法选取一名健康成年女性志愿者,进行腕部CT扫描,获取数据,按照尺骨茎突体部及基底部截骨,建立尺骨茎突骨折不愈合的模型,按骨块移位程度分为骨折不愈合间隙1mm的体部骨折模型组、间隙2mm的体部骨折模型组、间隙1mm的基底部骨折模型组、间隙2mm的基底部骨折模型组,在轴向压缩、横向拉伸和旋后扭转工况下,观察下尺桡关节和尺骨茎突骨块的相对位移值。结果在各个工况下,骨折模型组与正常模型组相比,下尺桡关节相对位移值无明显改变;在轴向压缩、横向拉伸工况下,各骨折模型组间,尺骨茎突不愈合骨块位移值相差不大;在旋后工况下,体部骨折模型组的骨块位移相比于基底部骨折模型组明显更低,表明前者不愈合骨块稳定性更好。结论基于尺骨茎突骨折的有限元分析,骨折不愈合对下尺桡关节稳定性影响不大;在前臂旋转时,尺骨茎突基底部骨折不愈合的骨块稳定性较尺骨茎突体部骨折差。

Objective To evaluate the effect of ulnar styloid fracture nonunion on the stability of the distal radioulnar joint using finite element analysis.Methods A healthy female volunteer was selected for a CT scan of the wrist,and an osteotomy of the ulnar styloid process body or base was performed to establish a nonunion model of the ulnar styloid process fracture.According to the bone chip displacement,they were divided into 4 groups,including the ulnar styloid process body fracture model group with a fracture nonunion gap of 1mm,the body fracture model group with a gap of 2mm,the basal fracture model group with a gap of 1 mm,and the basal fracture model group with a gap of 2mm.Under the conditions of axial compression,lateral extension,and supination,the relative displacement values of the distal radioulnar joint and the ulnar styloid process bone fragment were observed.Results Under each working condition,the relative displacement value of the distal radioulnar joint did not change significantly compared with the normal model.Under the conditions of axial compression and lateral extension,the displacement value of the nonunion bone fragment in each ulnar styloid process fracture group was similar.Under the condition of supination,the bone fragment displacement of the body fracture model group was significantly lower than that of the basal fracture model,indicating that the former nonunion bone fragment has higher stability.Conclusion Based on the finite element analysis of ulnar styloid process fractures,fracture nonunion has little effect on the stability of the distal radioulnar joint.When the forearm rotates,the stability of the nonunion bone fragment at the base of the ulnar styloid process is worse than that of the ulnar styloid process body fracture.