Replacement of the hip in children with a tumor in the proximal part of the femur.

BACKGROUND Children rarely require hip replacement, and therefore very little is known about the most effective procedure for children who require hip replacement after proximal femoral resection for a tumor. METHODS We reviewed the outcome of forty hip replacements in children between two and fifteen years old who had a proximal femoral replacement for malignant disease. Twenty-one children survived the illness and were followed for three to twenty-one years. Cemented acetabular components were used initially to restore hip function, but, in more recent procedures, unipolar replacements and uncemented implants were used. RESULTS Children who were over the age of eleven years at the time of surgery had a rate of failure (defined as revision of the acetabular component) of 25% at ten years compared with a rate of 75% in younger children. Unipolar replacements in children of all ages failed by ten years, either because of pain or subluxation that led to revision. In children over the age of eleven years, both cemented and uncemented acetabular implants performed well. CONCLUSIONS The preferred method for restoration of hip function in children under the age of eleven years following proximal femoral resection for a tumor remains unclear. We recommend that at the initial hip surgery an attempt should be made to cause as little damage as possible to the acetabulum, but most children will inevitably need revision surgery as they get older. We hope that this study will guide others in their decision-making with regard to this relatively rare condition.