456PUse of gamma irradiated bone allografts in treatment of various bone tumours.

Background Osteogenic augmentation is required in various orthopaedic conditions. Defects caused by removal of malignant or local bone tumours requires reconstructive surgeries to restore skeletal continuity and bone grafts to fill bone defects. Different modalities which can help to increase osteogenesis include autografts, allografts and synthetic bone graft substitutes. Autograft is the gold standard, provides osteogenic, osteoinductive and osteoconductive properties but has limitations of requirement for additional incisions, poor bone quality in elderly patients, increases operation time, causes donor site pain and morbidity and likely permanent residual disability and limited amount. Autograft is the gold standard but is available in limited amount and morbidities associated with it. Bone graft substitutes are costly, limited in quantity and don't integrate with host bone. Bone allografts are a good option, but not widely used in India and there are sparse reports in literature from developing countries. Our study signifies use of gamma irradiated deep freezed bone allografts in treatment of various bone tumours. Methods It's a prospective descriptive study. Strict inclusion and exclusion criteria, as per standard guidelines of American and European Association of Tissue Banking, were followed. We have a in-house facility of gamma irradiated deep freezed bone allografts available in hospital. 20 patients with giant cell tumours of proximal tibia, proximal ulna and distal radius, aneurysmal bone cysts of proximal humerus and distal radius, etc were operated during one year and followed up for atleast 24 weeks thereafter. Sloof's Criteria was used for assessing osteointegration of grafts. Results Allografts have not only accepted well but defects have healed and bone integration is at various stages. Only one patient got infected (5%). 19 out of 20 patients (95 %) in our study group had either attained or at various stages of osteointegration and healing. Conclusions We conclude that deep freezed bone allografts is a viable option in patients with large bone defects after resection of bone tumours, thus give satisfactory surgical outcome, with no serious side effects. Legal entity responsible for the study The authors. Funding Has not received any funding. Disclosure All authors have declared no conflicts of interest. [ABSTRACT FROM AUTHOR]