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

• Hemipelvectomy (PI-II) after rotationplasty on the same leg resulted in a good functional result in a 16 year old male patient with osteosarcoma. • For hemipelvectomy, the musculus gluteus maximus is essential for soft tissue coverage, therefore supplying structures must be preserved. • The triradiate cartilage of the acetabulum closes around a bone age of 12 years in boys and then is no sufficient barrier for an osteosarcoma. 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. 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. 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. 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. [ABSTRACT FROM AUTHOR]