[Internal hemipelvectomy: periacetabular resection with hip transposition]

Long-term stable fixation of the leg to the remaining ilium or sacrum following internal hemipelvectomy including resection of the acetabulum.

Bone sarcomas, soft tissue sarcomas infiltrating the bone, solitary late metastases, acetabular reconstruction failure.

Palliative treatment goal, mutilating resection (especially when the tumor extends beyond the midline of the sacrum).

Facilitation of stable fixation of the femoral head or proximal femur replacement to the remaining bone (ilium or sacrum,) following periacetabular pelvic resection. Insertion of 2-3 bone anchors in the ilium or sacrum, depending on the extent of tumor resection, alternatively transosseous sutures and attachment of a partially resorbable mesh, closed at the proximal end. Depending on the muscular coverage, repositioning of the hip or bipolar cup proximally. Attachment of the mesh to the remaining hip capsule or the megaprosthesis and the muscles. The reconstruction length must not compromise sufficient muscle coverage.

Elastic hip spica. Bed rest for 1-2 weeks, depending on the weight of the leg. Mobilization with a walker or 2 crutches with 20 kg weight bearing for the following 4-6 weeks. Lymphatic drainage/venous foot pump as required. Adjuvant chemo- or radiotherapy as per multidisciplinary tumor board recommendation.

The goal is the development of a stable scar around the neo-joint with minimal dead space. Young patients can often walk for several kilometers, typically using a walking stick on the contralateral side. Sole lift, lengthening of the femur at a later point if desired. There is a risk of wound-healing disorders or deep infections postoperatively in approximately 30% of cases. In case of infection, removal of the mesh and possibly of the proximal femoral replacement, as well as vacuum-assisted closure therapy may be necessary.