Qin Sihe surgical method combined with Ilizarov technique was used to treat 6 cases of complex knee leg deformity, including 4 males and 2 females, aged 5-28 years, 4 on the right side and 2 on the left side. There were 2 cases of congenital tibial hemilimb malformation, 1 case of congenital fibular hemilimb malformation and 1 case of multiple chondroma; There was 1 case of developmental deformity after injury of epiphysis of knee joint in young age, and 1 case of bone malunion of knee joint after infection of knee joint in young age. Qin Sihe operation combined with Ilizarov technique was used for traction reconstruction, including 4 operations in 1 case, 3 operations in 1 case, 2 operations in 1 case, and 1 operation in 3 cases. All patients were followed up for an average of 8 years. The deformity was corrected, the lower limbs were basically the same length, and the walking function was significantly improved. No major surgical complications occurred. Conclusion: Qin Sihe operation combined with Ilizarov technique can effectively reconstruct the shape and function of complex knee-lower leg deformity on the premise of limb preservation. The operation is simple and the medical cost is low. It is suitable for promotion in economically underdeveloped countries. 

Qin Sihe is a leading orthopedic surgeon and researcher at the National Research Center for Rehabilitation Technical Aids (NRCRTA) in Beijing. He had presided over 36664 operations of various limb deformities and disabilities, created the largest database of limb deformity surgery cases with the largest number of diseases in China, and formed Qin Sihe medical concept, diagnosis and treatment style, and limb deformity and disability surgery reconstruction technology system. He has published more than 400 papers and 12 monographs. He served as the president of the international limb lengthening and reconstruction society (ILLRS) and the international ASAMI society in China; Chairman of China branch of functional reconstruction of limb disability, chairman of China external fixation and limb reconstruction Committee, chairman of "Spina Bifida Society", and chairman of the Organizing Committee of the sixth world limb reconstruction Conference (ASAMI - ILLRS & BR, Beijing 2024).