经关节桡骨远端骨折后腕屈伸肌腱的动力学变化

Changes in kinetics of wrist flexors and extensors after intra-articular fractures of the distal radius

目的 :探讨经关节桡骨远端骨折后主要屈、伸肌腱的动力学指标力臂的变化规律。方法 :在 8只成人尸体上肢标本 ,截骨造成经关节面桡骨远端骨折 ,再将骨折片分别向背侧移位 1、2、3、4、5mm ,测定经关节面骨折在无移位 ,移位 1、2、3、4、5mm时 ,桡侧腕长、短伸肌腱、尺侧腕伸肌腱、桡侧腕屈肌腱和尺侧腕屈肌腱的力臂变化。结果 :在腕关节屈伸活动时桡侧腕长伸肌腱的力臂在骨折背侧移位 2、3、4和 5mm时较无移位时显著增大 (P <0 .0 5 ) ,而桡侧腕短伸肌腱和桡侧腕屈肌腱的力臂在背侧移位 1～ 5mm时均显著增大 (P <0 .0 5或P <0 .0 1) ,桡侧腕长、短伸肌腱的力臂增大数值和背侧移位成正比。结论 :经关节面桡骨远端骨折背侧移位显著影响腕动力学 ,随移位程度增大 ,腕屈。

Objective: To study changes in moment arms of wrist flexors and extensors after the displacement of intra-articular fractures of distal radius. Methods: In 8 adult cadaver upper extremities, moment arms of extensor carpi radialis longus and brevis, extensor carpi ulnaris, flexor carpi radialis and ulnaris were measured after dorsal displacement of intra-articular fractures by 0, 1, 2, 3, 4 and 5 mm. Results: Moment arms of the extensor carpi radialis longus was increased significantly after dorsal displacement of the fragments by 2, 3, 4 and 5 mm ( P <0.05). Moment arms of the extensor carpi radialis brevis and flexor carpi radialis tendons was increased significantly after the displacement of dorsal fragments by 1～5 mm (P<0.05 or P<0.01). The increase in moment arms of the radial wrist motor tendons was proportional to the extent of dorsal displacement of the fractures. Conclusions: The displacement of intra-articular fracture of distal radius exerted significant influence on wrist kinetics. Moment arms of wrist motor tendons were increased as the displacement of the fractures was more severe.