Metal-on-metal hip resurfacing in patients with arthritis secondary to congenital dysplastic hip / 中国矫形外科杂志

ABSTRACT

[Objective]To evaluate the safety and efficacy of total hip resurfacing arthroplasty in treating osteoarthritis secondary to congenital dysplastic hip.[Method]From May 2005 to June 2005,13 hips in 12 cases with osteoarthritis secondary dysplastic hip were adopted in this study.There were 8 females and 4 males,aged from 30 to 59 years,average 47 years.All the 13 hips were subluxation according to Hartofilakidis classification system.Posterolateral approach was used during operation and all the acetabular cups were reconstructed at the true acetabular location.The pronthesis were cementless acetabular cup and cement femoral head.[Result]The average operation time was 110 min,blood loss volume was 387 ml during operation,drainage volume was 200 ml and the extremity was lengthened for about 9 mm.All the incision healed well and there have not any complications such as femoral neck fracture,infection,dislocation and neurovascular injury.Follow-up for 12 to 13 months,all the joints had good or excellent clinical results.The average range of motion of the hip:flexion improved from 106.7? to 120?,abduction improved from 25.8? to 46.4?,external rotation improved from 20.8? to 45?,internal rotation improved from 3.3? to 28.6?.The Harris score increased from 42 preoperatively to 96 postoperatively.Radiographically,the positions of the prostheses were normal,the average abduction angle of the cup was 39?,the average stem-shaft angle wes 141?,the positions of acetabular rotation centre were moved down and medially for average 9 mm and 11.5 mm respectively,the acetabular superolateral bone coverage of the hips was 89.5%,no radiolucent line was observed.[Conclusion]Total hip resurfacing arthroplasty has got good short-term results in the treatment of osteoarthritis secondary to dysplastic hip.Because of the less quantity and short follow-up time,the long-term results and indications for other kinds of dysplastic hip are worthy of further studying.