外固定器背伸位固定治疗三踝骨折后踝顶针的生物力学研究

Biomechanics Study about the Half-pin on Posterior Malleolar when Trimalleolar Fracture is Treated by External Fixation in Dorsiflexion Position

目的:探讨外固定器背伸位固定治疗三踝骨折时使后踝骨折稳定的最佳踝关节固定位置。方法:应用手术截骨方法制作三踝骨折的尸体标本模型。复位后安装外固定器,并应用6根顶针复位与固定。于后踝顶针下表面贴应变片,并与应变仪导线连接。通过调整踝关节固定复位器,使踝关节固定于背伸中立、背伸内翻、背伸外翻3种位置。用试验机控制加载,应用应变仪采集顶针应变数据。实验结果经SPSS12.0统计软件进行统计分析。结果:后踝骨折背伸中立位比背伸内翻位及背伸外翻位固定稳定。结论:外固定器背伸位固定治疗三踝骨折时后踝骨折稳定的最佳踝关节固定位置是背伸中立位。

Objective ： To find out stable position of posterior malleolar fracture when trimalleolar fractures were treated by extemal fixation in dorsiflexion position. Methods： Making cadaver model of trimalleolar fractures by operation. External fixation was installed and six half needles were used for fixation. Stick straining flake on very nether surface of half needle of posterior malleolus. Then straining flake was connected with leads of strain gauge. Ankle joint position was adjusted in three different positions. They were dorsiflexion-neutral position, dorsiflexion-varus position, dorsiflexion-ecstrophy position. Numerical data was gathered by deformeter when experimentation machine loaded. Results： Posterior malleolar fracture was more stable in dorsiflexion-neutral position than in dorsiflexion-varus position or dorsiflexion-eestrophy position. Conclusions： Stable position of posterior malleolar fracture when trimalleolar fractures are treated by external fixation is dorsiflexion-neutral position.