Introduction: Angular and torsional deviations of femur are usually combined with Congenital Dislocation of the Hip (CDH) and increase the complications of hip arthroplasty. The aim of this study is to evaluate surgical and reconstructive options for the treatment of CDH.
Material and Methods: In this retrospective study, we evaluated the results and complications of 55 primary cementless total hip arthroplasties, all of whom had Crowe type-IV developmental dysplasia of the hip. The arthroplasty was performed in combination with a subtrochanteric shortening osteotomy and with placement of the acetabular component at the level of the anatomic hip center. The patients were evaluated at a mean of 8,1 years postoperatively.
Results: From 1984, more than 2000 cases of arthroplasty have been performed in dysplastic hip, 565 cases had a previous femoral osteotomy; 128 cases needed correction of femoral side deformity; 64 had a greater trochanteric osteotomy. In 9 cases rotational abnormality and shortening were controlled with plate and distal femur osteotomy. 55 cases were treated by a shortening subtrochanteric osteotomy. Only non-cemented stems were used. 4 failures occurred for the incorrect fixation of the metaphysis. The fixation can be obtained only by prosthetic press-fit, but it is preferable to use metal wires. There was no sciatic injury; indeed shortening osteotomy provides an easy control of deformity and lengthening, with a maximum of 4 cm. One case was reviewed for heterotopic calcification (grade 4). One infection of the soft tissue was medically cured. There were two revisions for polyethylene failure at 8 and 12 years postoperative.
Discussion: The anatomic abnormalities associated with CDH and previous femoral osteotomy increase the complexity of hip arthroplasty. We had best results with the femoral shortening subtrochanteric osteotomy where a rapid consolidation was obtained. Moreover, the functional result was better for the management of the insertion of the muscle tendons in particular the mediogluteus and also for the relatively correct positioning in favour of the reciprocal relationship of the pelvic-trochanter. The detachment of the greater trochanter associated with a metaphyseal proximal shortening, remains an effective technique for the treatment of malformations that are difficult to treat, but there is a high risk of pseudarthrosis of greater trochanter.
Conclusion: Femoral shortening subtrochanteric osteotomy preserves the proximal femoral anatomy, avoids the problems associated with reattachment of the greater trochanter, and facilitating a cementless femoral reconstruction in relatively young patients.
