Behaviour of autoclaved massive autologous bone grafts - an experimental study

Abstract

Comparative behaviour of massive autogenous bone grafts was studied in 3 groups: Group-A (control), Group-B (autoclaved), and Group-C autoclaved supplemented with fresh autogenous cancellous bone (composite). The parameters of study were radiological, macroscopic, histological and tetracycine fluorescence observed up to a period of 36 weeks after reimplantation. No foreign body reaction or immunological rejection phenomenon was found. The grafts were reasonably cellular, vascular and incorporated by 18 weeks in the control (Group-A) and by 36 weeks in the autoclavd-composite graft (Group-C). Even in the autoclaved graft (Group-B) macroscopic adhesion, pink colour, appreciable cellularity and presence of tetracycline fluorescence was observed between 24 and 36 weeks. The cancellous region in general showed early and intensive vascularity, cellularity and fluorescence. Correlating the radiological, macroscopic, histological and tetracycline fluorescence observations in the present study it may be stated that an autoclaved autologous bone segment can provide an inert durable frame work to bridge a gap in a major bone when a better graft is not available. In clinical practice this may be applicable in cases of tumours which could be resected en-bloc. The resected mass of bone by heat treatment could be sterilised of malignant cells as well as of any organisms, and reimplanted to bridge the defect by the easily available material. Revascularisation and resorption could be speeded up by increasing the porosity of the heat-treated bone by a chemical or physical method. Bone forming property of the autoclaved implant could also be improved by impregnating the graft with fresh autologous cancellous bone or any other suitable osteoinductive agent. Thus the scaffolding of the autoclaved bone segment could be used as an expander of the bone forming capacity of fresh autologous cancellous bone.