Iliosacral fixation after type-1 hemipelvectomy: a novel technique.

Involvement of the iliac bone and a sacroiliac joint with malignant tumours is not uncommon; treatment is difficult due to the anatomy of the pelvis. Resection of the tumour mass must be extensive in order to achieve safe margins, but this may lead to instability and poor results. We present a new technique for reconstruction after resection of the iliac bone and sacroiliac joint including a sacral ala, and we present two illustrative cases, with 2 years follow-up. Following en bloc resection of a chondrosarcoma in the iliac bone, two or three polyaxial pedicle screws were placed transversly into the sacrum. Two polyaxial pedicle screws were also inserted into the remaining pubic and ischial bone respectively. After completion of the construct with rods, a cortical strut graft from the ipsilateral fibula was placed between the rods. Next a split mesh was placed around the implants and was filled with 60 cc bone chips allografts. Both patients were mobilized with crutches and partial weight bearing for 4 weeks and then full-weight bearing. After two years follow-up, they were ambulatory without external support and their radiological results remained satisfactory. This technique for reconstruction after type I pelvic resection is advantageous in that it saves mobile lumbar segments.