The patients were divided randomly into three groups : group A , the patients with remained length of tibial stump ranging from 15 to 20 mm , including 8 males and 6 females , with an average age of ( 28.2 6.6 ) years old ; group B , the patients with remained length of tibial stump ranging from 5 to 10 mm , including 9 males and 5 females , with an average age of ( 27.9 6.4 ) years old ; group C , the patients with remained length of tibial stump less than 2 mm , including 9 males and 5 females , with an average age of ( 28.6 6.8 ) years , old .