Utilisation des allogreffes en oncologie et en traumatologie

Abstract

Fresh allografts of bone are commonly used for repairing small defects, but preserved grafts are required for replacing large sections of long bones. We have collected these grafts in sterile conditions and then preserved the specimens in liquid nitrogen at minus 196 degrees Celsius. Biological, histological and biomechanical studies have confirmed the value of this technique. The method preserves the normal architecture of bone and viable cartilage cells. The medullary cells are gradually destroyed in situ leaving a protein matrix to which mineral components are fixed. Neither of these are antigenic in allografts and immunological problems are rarely encountered. When the recipient site is well vascularised the graft becomes fully integrated within two or three years. Doubt has been expressed as to the functional viability of the cartilage in large allograft joint replacements, and is has been suggested that metal prostheses might be better. Research is in progress in the use of ligament allografts and on the use of bank bone with large prostheses. The functional results are satisfactory in more than 90% of patients treated with these large allografts.

Adverse reactions and events related to musculoskeletal allografts: reviewed by the World Health Organisation Project NOTIFY

“…The surgeon should select the proper allograft taking into account the likely modification of the mechanical resistance produced by the different processing techniques and the mechanical requirements of the particular clinical application. For instance, a deepfrozen allograft may have better mechanical resistance than the original bone (± 110%) [3,38,40] while freeze-drying processing will decrease its resistance (30-40%) [25,36,40,47,51]. The effect of sterilisation by gamma irradiation on the mechanical properties of the bone is a function of the dose.…”

“…The level of 25 kGy, generally accepted for bacterial inactivation, can affect the mechanical properties of soft tissues but not significantly of bone [2,38,49,55,59]. However, virucidal doses over 30 kGy decrease the mechanical strength of bone [2,7,18,38,40,42]. Also depending on the size of the bone graft, the revascularisation and progressive integration decrease the mechanical resistance over several months [4,40].…”

“…However, virucidal doses over 30 kGy decrease the mechanical strength of bone [2,7,18,38,40,42]. Also depending on the size of the bone graft, the revascularisation and progressive integration decrease the mechanical resistance over several months [4,40]. Good communication with the tissue bank staff will help the surgeon to select the adequate type and size of the allograft for its specific purpose including the osteoinductive properties expected from demineralised bone matrix allograft [16,20].…”

Limb Salvage for Malignant Bone Tumors in Young Children

“…The introduction of the new methods, namely diagnosis by image (25,28,31,35,45,52,56) and use of preoperative chemotherapy (2,3,33,39,42,44,(47)(48)(49), contributed to indications for limb salvage. An increasing interest in limb-reconstruction techniques after resections has thus developed (1,4,8,(9)(10)(11)(12)14,15,(17)(18)(19)(20)(21)(22)24,26,27,29,32,3638,40,41,46,51).…”

Reconstructions iliaques totales ou partielles � l'aide d'allogreffes de banque

“…L'utilisation d'allogreffes massives de bassin cryoc0nserv6es dans de l'azote liquide ~t -196°C, nous a paru ~tre une m6thode efficace donnant un r6sultat fonctionnel optimal lorsqu'elle est r6ali-s6e dans des conditions pr6cises [3,5,7,12,22].…”