Utilisation des allogreffes en oncologie et en traumatologie

Summary

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° 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.

Résumé

Les autogreffes ont un potentiel ostéogénique indiscutable que ne possèdent pas les allogreffes mais le volume des prélèvements ne pouvant être que de faible importance, elles ne permettent pas de reconstruire un os ou une articulation qui a du être en partie ou en totalité réséqué, du fait de l'existence d'une tumeur osseuse ou d'une perte de substance posttraumatique.

C'est la raison qui nous a poussé depuis 1971, à utiliser des allogreffes fraîches, puis à partir de 1981, des allogreffes cryopréservées pour reconstruire le squelette.