Abstract: Objective To study the design and fabricating method, biomechanical effect and practicablity of the orthosis for patients suffering from large femoral bone defect and leg length discrepancy and study the effect of the orthosis on patients' equilibrium, walking function and gait. Methods By four stages we finally made ischial weight bearing orthosis with prosthetic feet, and then analysed its biomechanical effect and efficiency, evaluated balance and walking function of patients.Results The orthosis, according with principle of biomechanics, realized patients' wish of walking without crutch. The energy consumption and balanced capacity of patients wearing orthosis were much better while walking distance parameters came close to normal. Conclusion Ischial weight bearing orthosis with prosthetic feet can help patients reconstruct walking function, therefore can be recommended.

Key words: femur, bone defect, leg length discrepancy, walking function, orthosis