Tendon insertions onto allografts pretreated with heat and/or bone surface demineralization

Tendon insertions onto allogeneic bone grafts were studied histologically and biomechanically in 132 rats. Before grafting, allogeneic bone was treated at different temperatures or partially demineralized or both. Mesenchymal cell and fibrous tissue invasion were easily recognized in non-heat-treated allograft groups and in groups with allografts incubated at 70 degrees; invasion was not observed in autoclaved (130 degrees) allograft groups. New bone formations were found between the tendon and the surface-demineralized allografts in the non-heat-treated and 70 degrees-treated bone groups but not in the autoclaved group. Allografts pretreated with heat demonstrated graft-insertion tensile strengths lower than in non-heat-treated and 70 degrees-treated allografts. Surface-demineralization enhanced graft-insertion tensile strengths in the non-heat-treated and 70 degrees-treated groups, whereas the tensile strength of attachments in noninductive, autoclaved allografts was not enhanced.