A COMPARISON OF AUTOGENOUS CORTICO-CANCELLOUS BONE-GRAFT OBTAINED FROM THE WING OF THE ILIUM WITH AN ACETABULAR REAMER TO AUTOGENOUS CANCELLOUS BONE-GRAFT OBTAINED FROM THE PROXIMAL HUMERUS IN DOGS

The incorporation of autogenous cortico-cancellous bone graft (CCBG) h arvested from the wing of ilium using a powered acetabular reamer and autogenous cancellous bone graft (CBG), harvested from the proximal hu merus by curettage, were compared in four young adult mixed breed fema le dogs. Five milliliters of CCBG or CBG were placed in bilateral, sta ble, 3.0 cm proximal diaphyseal ulnar defects. Humeral donor sites, an d subsequent assignment of graft types of ulnar recipient sites, were alternated between dogs. Craniocaudal and lateral view radiographs wer e obtained immediately (day 0) and on days 16 and 35 after the operati on. Photodensitometric and bone graft area measurements were made from these radiographs and the specific radiographic characteristics of th e bone grafts were described at each time interval. Each dog received a series of intravenous fluorochrome label injections on days 23, 28 a nd 33. The dogs were humanely euthanatized on day 35. The bone graft r ecipient sites were harvested, processed and the descriptive histologi cal and histomorphometric parameters were evaluated. A statistically s ignificant difference in photodensitometric measurements was not seen between the CCBG and CBG. However, there was a statistically significa nt increase in the graft area of the CCBG from day 0-16. Mineral appos ition rate was significantly greater, (P = 0.005) for the CCBG (mean = 4.8) than for the CBG (mean = 3.7), suggesting that the CCBG appears to be in an earlier more osteogenic phase of incorporation than the CB G. There was a trend which suggested that the percent age of trabecula r bone volume was greater (P = 0.11) for the CBG (mean = 43.0) than fo r the CCBG (mean = 32.0). Other significant differences were not found , with respect to the other morphometric parameters measured. The desc riptive histology and subjective radiographic evaluation were the most effective ways of readily distinguishing between the two types of bon e graft and they demonstrated that the CBG had incorporated more compl etely than the CCBG by day 35.