复位固定器治疗桡骨远端骨折的在体力学测试

Biomechanical test in vivo on reduction fixator for treating distal radius fractures

目的研究穿针复位固定器治疗桡骨远端骨折过程中牵引力的变化规律。方法利用自行设计的测力锁针器替代复位固定器远端2枚锁针器,对6例复位固定器治疗的不稳定桡骨远端骨折患者前臂的牵引力进行临床在体连续测试。分别于术后第1、5、14、21、28、35、42、49 d,记录静态牵引力值及握拳活动时牵引力增加值。结果测得静态牵引力值最大9.93 kg,最小2.26 kg,平均(4.93±1.79)kg;握拳活动时牵引力最大增加10.40 kg,最小增加0.13 kg,平均(3.17±2.42)kg。结论前臂肌肉张力及肌肉收缩活动可产生较大的轴向压应力,是桡骨远端不稳定骨折的不利因素。

Objective To investigate the regular pattern of traction forces during the treatment of distal radius frac- ture by reduction fixator with pins. Methods A self-designed pin-lock style force transducer instead of two origi- nal pin-locks in the distal of reduction fixator was adopted to conduct continuous testing on six cases of unstable distal radius fracture of forearms treated by reduction fixator in vivo. The value of static traction force and the add- ed value of traction force in fist clenching at the postoperative 1st, 5th, 14th, 21st, 28th, 35th, 42nd, 49th day, was recorded respectively. Results The maximum and minimum static traction force was 9.93 kg and 2.26 kg, respectively, with mean value of （4.93 ±l. 79） kg. The maximum and minimum traction force increment in fist clenching was 10.40 kg and O. 13 kg, respectively, with mean value of （3.17 ± 2.42.） kg. Conclusions Larger axial forces can be generated in muscles of the forearm, by both static tension and dynamic contraction, which might be a serious negative factor in healing unstable distal radius fractures.