人体踝关节在跖屈位时光弹性应力试验和临床应用

The Photoelastic Stress Experiment and Clinical Application on Human Ankle Joint at Plantar Flexion Position

目的 :采用光弹性应力实验 ,分析踝关节在不同跖屈位时踝关节负重区应力的大小和分布状况。根据实验结果探讨枷足行踝后骨阻挡术后留置足下垂的角度 ,以符合踝关节生理解剖和生活功能的要求。方法 :采用光弹性应力试验 ,测定踝关节在 5种不同跖屈位时 ,关节面接触应力的大小和分布规律。在临床上 ,根据实验结果将 42例改良的踝后骨阻挡术下垂活动范围限制在最小 5° ,最大 10°。结果 :通过光弹试验测定踝关节面的应力和分布与关节屈曲角度有关。在跖屈 7°时 ,应力最小 ,且分布均匀 ;跖屈 19°时 ,随跖屈角度增大 ,应力值显著增大 ;在43°时应力值更明显 ,形成集中分布。本组随访 42例踝后骨阻挡术 ,下垂角度限制在最小 5° ,最大 10° ,随访时间 4～ 13年 ,平均 8年。其中改良的距骨结节延长术 19例 ,优良率 94 7% ,改良跟骨阻挡术 2 3例 ,优良率 78 2 % ,并发症明显减少。结论 :人体踝关节光弹性应力实验揭示了踝关节在不同跖屈时的应力分布和大小 ,在临床上指导了踝后骨阻挡术术后留置的下垂角度。同时在预防医学上 ,通过计算也指导了在阅兵军训时穿多高鞋跟的军靴和女同志穿在生理解剖允许范围内最高鞋跟的高跟鞋 ,减少踝关节疲劳和损伤。

Objective:To analyze the stress magnitude and distribution of weight-bearing area on human ankle joint at different plantar flexion,the photoelastic stress experiment was performed.After the operation of bone block of posterior ankle,the most suitable angle range of plantar flexion was studied,which is fit for physiological anatomy and living function.Methods:The photoelastic stress experiment were performed,the stress magnitude and distribution of weight-bearing area on human ankle joint at 5 different position of plantar flexion were analyzed.According to the experiment results,the plantar flexion angles of ankle joints were set to the position from 5° to 10° when the modified operations of bone block of posterior ankle were performed.Results:The photoelastic stress experiment showed that there was a close relationship between ankle flexion position and stress distribution.The results showed that when the plantar flexion was at 7°,the contact stress distribution area was the greatest,the pressure stress was the least,and the distribution was the even; when the plantar flexion was over 19°,the contact stress distribution area began to decrease and the pressure stress was increased; and when the plantar flexion was over 43°,the contact stress distribution area was decreased significantly,42 cases of patients were followed up.The follow-up period was from 4 to 13 years,averaged 8 years.Of them,the excellent and good rate of the talus tuberosity lengthening operation of 19 cases and the calcaneus block operation of 23 cases were 94.7% and 78.2% respectively.The complications were decreased.Conclusion:The photoelastic stress experiment display the distribution and magnitude of the ankle joint at different plantar flexion.In clinical use,the photoelastic stress experiment about stress distribution and magnitude on different plantar flexion instructed the ideal angle of the ankle plantar flexion of the modified operation of bone block of posterior ankle.On the preventive medicine,the result of photoelastic stress experiment also instructed the heel highth of high-heel shoes and boots which will be worn by women and female soldier on daily life or on parade,so as to prevent the fatigue and injury of the ankle joints.