Abstract: Objective: To evaluate the efficiency of improved Zahradnicek operation in treatment of congenital hip dislocation and measures to prevent the complications.Methods: Two hundred and sixty two cases of congenital hip dislocation(196 patients) from 1992 to 2002 underwent improved Zahradnicek operation.The acetabulum was expanded and deepened to Y cartilage with a suitable drill;meanwhile the surface of cartilage was reserved as far as possible so that the acetabulum could cover 2/3 of the femur head.Under direct observation of the anteversive angle and cervical shaft angle,the femur osteotomy of corresponding subtuberosity of cuboid bone was performed according to different deformities.The femur was cut down about the length of 1.5-3.0 cm and fixed with 115° angle curved steel.Anteversive angle 5°-10° and cervical shaft angle 115° were retained.Results: Ninety-six hip joints of 66 patients were available at final follow-up.The results were excellent in 53.1%,good in 30.2%,fair in 10.4% and poor in 6.3%.The excellent and good rates were 83.3%.There were confined activity of hip joints in 14 cases;hip joint dislocation or semidislocation in 12 cases;femural head sterile necrosis in 9 and nonunion in 1.Conclusions: This method can completely or nearly restore the hip joint to normal anatomic and functional position,but its complications should also be attached importance to. Back