Abstract
Subcutaneous combined grafts with HA granules and bone marrow were done in the rabbit, and 1) bone formation and modality of HA-bone complex in the combined grafts with HA granules and fresh autogenous bone marrow, 2) bone formation with combined grafts of HA granules and homogeneous bone marrow, and 3) comparison of bone formation in the combined grafts with four categories of HA granules and autogenous bone marrow were investigated.
Our newly developed HA granules and three kinds of HA granules on the market were used in the present experiment. Autogenous or homogeneous bone marrow was obtained from New Zealand white rabbit tibia. Combined materials of each HA granule and bone marrow (volume ratio; 1:1) were grafted on the abdominal subcutaneous tissues of the rabbits. Specimens, removed progressively and stained with hematoxylin and eosin after decalcifying, were observed histologically.
The results were as follows:
1. In the combined grafts with HA granules and fresh autogenous bone marrow, new bone formation, which was induced by osteoprogenitor factor in bone marrow, connected with HA granules in proportion to its maturation and ossicles similar to growing bone with marrow inside were formed.
2. The process of this bone formation was essentially the same as that in fresh autogenous bone marrow used as control.
3. Bone formation in combined grafts of HA granules and homogeneous bone marrow was not recognized.
4. As for compassion of bone formation in combined grafts of four categories of HA granules and autogenous bone marrow, the process of bone formation was different due to chemical composition and shape of HA granules. Especially, in HA granules of Ca excessive contained type and high solubility shape, initial osteoconduction and HA-bone complex formation were disadvantageous.
5. These findings suggested that, considering the behavior of HA granules, this combined graft is used effective in clinical application to soft tissue.
