游离髂骨重建跖骨缺损的三维有限元及临床分析

目的 了解1～3跖骨缺损以髂骨重建后对足功能的影响。方法 在足骨骼三维模型上模拟1～3跖骨50％及100％缺损，采用髂骨重建，以有限元法计算得到的最大位移及最大应力为指标，分别评估跖骨缺损和重建后足的位移及应力。分析1996年3月～2003年1月5例跖骨缺损以游离带血管髂骨串联皮瓣重建后的疗效。结果 1～3跖骨缺损对足功能影响较大，与完整足相比较，缺损100％最大位移增加2．15倍，最大应力增加2．12倍；缺损50％最大位移增加1．65倍，最大应力增加2．05倍。模拟髂骨块重建跖骨缺损100％及50％后，最大应力及最大位移与正常数值相近。临床应用的5例，术后骨瓣及皮瓣均成活，随访1～2年。按Maryland足功能评价：优2例，良2例，可1例。结论 1～3跖骨缺损应修复，游离髂骨串联皮瓣移植是较为理想的手术方式。

3-D FINITE ELEMENT AND CLINICAL ANALYSES OF THE RECONSTRUCTION OF THE FIRST TO THIRD METATARSUS DEFECT WITH ILIUM

Objective To investigate the effect of first to third metatarsus defect and the effect of reconstruction with ilium on foot function. Methods The first to third metatarsus defect was simulated in a 3D foot model and rebuilt by ilium. The maximal displacement and stress calculated by the method of finite elements were used as the index of estimation. Five cases treated from Mar. 1996 to Jan. 2003 with metatarsus defect rebuilding by free vascular iliac bone incorporating free flap were evaluated. Results Foot function was affected largely by the defect of the first to third metatarsus. Compared with the normal foot, the maximal displacement was increased by 2.15 times and the maximal stress was increased by 2 12 times in 100% defected foot, and in 50% defected foot maximal displacement and stress were increased by 1.65 times and 2.05 times respectively. Follow up had been conducted for 1 to 2 years. All bones and flaps of the 5 cases survived (2 excellent, 2 good, and 1 passable) by function evaluation. Conclusion The first to third metatarsus defect should be repaired, and the method of transplanting iliac bone added by flap is effective.