[Osseous echinococcosis].

Hydatid disease is caused by the parasitic tapeworm Echinococcus. The larval stage of this parasite can thrive in many parts of the body, most frequently in the liver. Primary bone location is very rare, accounting for less than 2% of all hydatid lesions. We report on a case of left-sided extended pelvic infestation. The destruction of the hip joint, os pubis, large parts of the ileum and the femoral head made pelvic resection and prosthetic replacement necessary. Recurrence of a hydatid cyst 5 years later in the left groin originating from the proximal femur was treated with second femoral resection and new total hip replacement. Because of instability, the primarily inserted polyacetal pelvic replacement had to be exchanged for a custom-made device fabricated with the aid of computer-aided design (CAD) techniques. This surgical procedure was combined with chemotherapy (mebendazole). The necessity of radical resection in osseus hydatid disease is discussed.