Osteogenic enhancement of diaphyseal reconstruction. Comparison of bone grafts in the rabbit.

We investigated incorporation of autoclaved autografts in segmental defects of rabbit humeri for comparison with a previous study on similar grafts supplemented with demineralized allogeneic bone matrix (DABM). We also made similar reconstructions with frozen allografts--both DABM and nonsupplemented allografts. Before the animals were killed at 8 months, they underwent scintigraphy, showing that all 28 humeral reconstructions were metabolically active. Faxitrone radiography showed nonunion in three of nine with autoclaved autografts and in two of eight with frozen allografts, whereas all 11 DABM-supplemented frozen allografts had incorporated. Taking into account only the 23 healed reconstructions, the mean torsional strength in relation to the contralateral nonoperated on humeri was 0.81 for all three groups. Histologically, new bone enveloping, partly replacing, the implants was more abundant in DABM-supplemented reconstructions. Our study shows that osteogenic enhancement is more important than the type of nonviable bone chosen for diaphyseal repair. However, if healing is obtained, osteogenic enhancement per se does not increase the strength.