Retrospetive Study Of The Clinical Effect Of Total Hip Arthroplasty For Treatment Of Osteoarthritis Secondary To Developmental Dysplasia Of The Hip

Objective To summarize the technique and effect of the total hip srthroplasty in the treatment of hip osteoarthritis secondary to developmental dysplasia of the hip(DDH).Methods A retrospective study was made on 48 hips in 38 patients(33 female and 5 male;average age,57.2±13.2years) with osteoarthritis secondary to developmental dysplasia of the hip(DDH) who were treated by total hip arthroplasty with use of an uncemented cup.Cemented femoral prothesis was used in 5 patients(6 hips) and the uncemented was used in 33 patients(42 hips).Six patients(6 hips) required autogenous femoral head grafts due to acetabular deficiency and 2 patients(2 hips) required subtrochanteric osteotomy.The average time of follow up was 37.6±17.2 months,ranged 11-71 months.The clinical evaluation was made according to the modified Harris hip score and the radiographic evaluation was made according to the X-ray photographes token pre-and postoperative.Results According to the modified Harris hip score,the average score increased from 39.9±11.3 at preoperation to 88.4±7.5 at the final review. The average degree of Sharp angle decreased from 47.1°±4.9°at preoperation to 32.9°±6.6°at postoperation.The average degree of CE angle of GradeⅠand GradeⅡpatients(37 hips) in Perner's classification increased from 8.1°±10.7°at preoperation to 39.7°±9.5°at postoperation.All autografts were seen to be united to host-bone with low level of bone resorption seen in one hips.The union was also seen in all hips treated with subtrochanteric osteotomy.Dislocation of the femoral prothesis occurred in two patients(two hips) after operation. The evidence of loosening of component was seen in no hip and no one need to be revised.Conclusion Total hip arthroplasty for osteoarthritis secondary to DDH can obtain favorable results.The primary and secondary pathoanatomical change of DDH before the operation.The uncemented acetabular cup should be used as far as possible.The key points for the success of total hip arthroplasty are as follows:restore the normal rotation center of the hip joint as far as possible and strict control of the indication of autogenous grafts.