Hip transposition procedure due to osteosarcoma metastasis of the ilium in a patient with preexisting rotationplasty leads to satisfactory functional result: A case report

INTRODUCTION: The hip transposition is a limb salvage procedure for periacetabular malignancies. Here we present the case of a patient that already had a preexisting ipsilateral rotationplasty. PRESENTATION OF CASE: A 16 year old male patient with an Osteosarcoma of the left distal femur was treated with wide surgical resection of the tumor and rotationplasty (Salzer/Winkelmann type A1). Despite adjuvant chemotherapy (EURAMOS protocol) he was diagnosed with metachronous metastases in the lung and in the left ilium affecting the acetabulum. As a limb salvage procedure the patient received an internal hemipelvectomy Enneking PI-II and an attachment of the femoral head with a Trevira tube to the sacrum using suture anchors. After six weeks a prosthesis was fitted and gradually full weight bearing was allowed. The patient achieved a good functional result as he was able to walk freely for three more years before he passed away. DISCUSSION: The hip transposition procedure does not require the implantation of a large tumor prosthesis and thus avoids the problem of an increased risk of infection. Even with preexisting ipsilateral rotationplasty a good functional outcome that allowed the patient full weight bearing could be achieved. CONCLUSION: If there are already existing deformities, such as rotationplasty on the same leg, the hip transposition procedure can be considered for periacetabular malignancies, as it can achieve satisfactory results.