桡骨远端关节内骨折伴腕关节不稳定放射诊断

目的 分析继发性腕关节不稳定与桡骨远端骨折类型的关系，讨论腕关节不稳定发生机制和防治措施。方法 对67例共75个腕部桡骨远端关节内骨折随访2a～6a，在复位前、后和去除外固定后的腕关节正侧位平片上分别测量腕高指数、尺腕距离比、舟月骨距、舟月骨角、桡月骨角、头月骨角，并测定腕关节功能的主、客观指标。比较合并与不合并腕关节不稳定两组的功能恢复情况。结果 伴有腕关节不稳定的发生率为58．67％（44／75），其中，腕背侧镶嵌不稳定（DISI）29例（38．67％），舟月骨分离9例（12．00％），其他为掌侧镶嵌不稳定、尺侧偏移和头月骨间不稳定等，多发生在严重骨折移位患者。骨折愈合后，合并腕关节不稳定的功能明显差于单纯桡骨远端骨折患者。结论 桡骨远端骨折类型、关节面弧度和掌倾角对腕关节不稳定的发生及类型有显著影响。对骨折移位严重或高能量损伤的桡骨远端骨折，要注意是否合并腕关节不稳定。对合并腕关节不稳定的桡骨远端骨折．复位时应尽可能恢复掌倾角.

Radiological diagnosis of carpal instability associated with intraarticular fracture in distal radius

Objective To analyse carpal instability related to the fracture type of the distal radius and to investigate the mechanism of distal radical fracture in combination with carpal joint instability and its prevention and treatment. Methods 67 cases of distal radical fracture were followed up for 2-6 years. Wrist joint anteroposterior and lateral view of radiography was examined at the time of pre-reduction, post-reduction and removal of extra fixation. Measurements in the x-ray PA film were: carpal height ratio(CHR) ,carpal ulnar distance ratio(CUDR), scapholunate gap(SLG). In the lateral view, to measure scapholunate angle (SLA) , radiolunate angle (RLA), and capitolunate angle (CLA), Objective and subjective criteria were checked for function of wrist joint. Function restoration between two groups with or without wrist joint instability was compared. Results Among 75 fractures of the distal radius, 44 fractures were accompanied with carpal instability, with an incidence of 58.67 %. Six patterns of instability were observed. Dorsal intercalated segment instability (DISI) and scapholunate dissociation were dominant,which occurred frequently in the severe displacement caused by high energy force. Functions of wrist joint in cases with wrist joint instability were significantly inferior than that with simple distal radical fracture after fracture union. Conclusions The occurrence and patterns of carpal instability were related to the type of fracture, cure and palmer tilt angle of the distal radial articular surface. It should be noticed whether wrist joint stability was complicated in distal radical fracture with severe dislocation or high energy injury. For that distal radical fracture with wrist instability, palmar tilting angle should be restored when reduction was done.