| Background:Developmental dysplasia of the hip (DDH) or congenital hip dysplasia (CDH) includes a wide spectrum of hip abnormalities ranging from dysplasia to subluxation and complete dislocation of the hip joint. It significantly affects the daily life of its adult patients, and the only way to fully cure the end stage of this disease in adult is total hip arthroplasty (THA). However, there always seem to be bone defects due to deformities of the acetabulum, leading to insufficient coverage of the acetabular cup during THA. So we need to provide adequate bone coverage to insure the stability of the cup in those with severe defect of the acetabulum. Nowadays, several methods was reported to increase the coverage and each has its own advantages and flaws. We can get satisfactory results by the treatment of total hip arthroplasy. Recently, researchers suggested that reconstructing the acetabulum with femoral-head required during THA for auto-grafting, which leads to early incorporation of the graft and avoid the instability of the cup due to the absorption of the grafted bone, as well as lessen the cost for treatment. Moreover, there seems not to be a consensus on choosing cemented or cementless press-fitting cup along with bone grafting world-wide. Some researchers insisted that, cemented cup with bone auto-grafting would probably lead to higher rates of implants failure.Objective:The current study aimed to discuss the effect of using the femoral-head required from THA for the auto-grafting to correct the bone defect of the acetabulum resulted from the deformities caused by DDH, enhance the coverage rate of the cup and therefore increase the stability. Using the preoperative and the postoperative Harris scoring system and radiographic parameters, as well as the circumstances during THA, we evaluated the function of the hip after reconstructing the acetabulum with femoral-head auto-grafting. At the same time, we also compared the short-term effect of two different types of cups, cemented or cementless press-fitting, to evaluate the differences between these two methods used with femoral-head auto-grafting.Method:Collect and retrospectively analyze the patients with Crowe type II or III DDH, who received THA from August 2007 to May 2010. The clinical parameters of 23 patients (24 hips) were recored. Among these patients, there are 3 males (3 hips) and 20 females (21 hips). The surgical technique was reconstructing the acetabulum with femoral-head required from the operation for auto-grafting, then choose whether cemented (Group A) or cementless press-fitting (Group B) cup to perform THA. The preoperative planning and radiographic parameters includes an anteroposterior (AP) view of the pelvis and AP and lateral views of the affected hip, computed tomography (CT) images are also needed to more accurately evaluate the bony deficiencies of the acetabulum and the marrow cavity of the femur in patients with DDH. At the same time, we also evaluated the function of the affected hip preoperatively, using Harris scoring system. During the operation, we performed osteotomy of the femoral head and carefully prepared it to fit the bony deficiencies of the acetabulum, implanted it and fix it with scrwes. Then we reamed the acetabulum and performed THA as routine. As a method of evaluating the stability of the cup and the incorporation of the grafted bone, after the operation, an AP view of the pelvis was examined at 3 months,6 months, a year and the end of the follow-up, three dimensional CT images was also examined if possible. Meanwhile, we recorded Harris scoring at each stage in order to evaluate the function of the hip. Besides, we compared the differences between the two groups combining the type of the cup, methods for fixation and the rate of coverage.Result:Totally,21 cases (22 hips) was successfully followed up, and 7 cases (7 hips) were from group A, while 14 cases (15 hips) were from group B, with an average follow-up period of 5.5 years. At the end of the follow-up, the wound healed by first intention in all patients, without related complications. Loosening of the cup occured in 1 case from group A, while in group B, no sign of loosening was found. In each group, there is 1 case of myositis ossificans, but the function of the hips were intact. The average Harris scoring in group A was 76.2, while was 86.2 in group B. Compared with preoperative Harris scoring, patients from both groups showed an elevated trend (P<0.05). However, no statistical significance was found between thses two groups (P>0.05). The post-operative radiographic images at 3 months after the operation showed satisfactory incorporation of the grafted bone in group B, with few sign of absorption, but less satisfactory in group A. While at 1 year after the operation, the incorporation became good.Conclusion:For adult DDH patients, satisfactory results was found in THA using whether cemented or cementless press-fitting cup, under the circumstance that reconstructing the acetabulum with femoral-head auto-grafting to increase the rate of coverage to more than 50%. However, although the rate of incorporation was almost equal in two groups 1 year after the operation, this rate in group with cemented cup was lower than that in cementless group in the first 3 months after the operation. |
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