Experimental treatment of the diaphyseal bone defect by using tricalcium phosphate

Summary

AIM:
Bone defects are, in particular, the problematics of traumatology, orthopedics and oncology. The traditional method of treatment is autospongioplastics, nowadays the use of absorbable materials with osteoinductive properties (tricalcium phosphate - ChronOS)1,2 is in the forefront. The aim of the submitted study is to verify the application of tricalcium phosphate itself as a treatment of a large diaphyseal bone defect in a model of a miniature pig. A positive result could reduce the necessity of bonegrafting and thus simplify the whole process of treatment. The results obtained will serve as technological starting points for further studies regarding the possibility of replacement of bone defects by mesenchymal stem cells.

MATERIALS AND METHODS:
The experimental group was made up of 25 miniature pigs from the certified breeding of the Institute of Animal Physiology and Genetics Academy of Sciences. In 12 pigs the tricalcium phosphate as a replacement of the defect was used and in 13 pigs autogennous cancellous graft was used. The tricalcium phosphate, or autograft, was applied and fixed into the diaphy-seal bone defect, which was formed. In both groups the fixation was carried out by means of LCP and application of intramedullary Kirschner wire. After healing, this area was processed from the histological point of view and evaluated with respect to the new formation of bone tissue and engraftment to the original bone, in the area of the edges of the defect.

RESULTS:
The results demonstrate that in the group with the application of autografts, more distinctive new formation of the mature bone tissue occurred. While evaluating the edges of the defect with regard to the engraftment to the original bone, the results in the group with the application of autograft were distinctively better.

CONCLUSION:
In the experiment conducted, the expected osteoinductive properties of the tricalcium phosphate itself have not been confirmed for the extensive defect of the femoral diaphysis. It is necessary to go on searching for the replacement of autospongioplastics by another noninvasive method for the treatment of extensive bone defects, by means of conducting experiments. The starting point might be the applied surgery method and the use of an appropriate biological carrier that will provide a mechanical support in combination with the tricalcium phosphate or mesenchymal stem cells.

Key words:
bone defect, tricalcium phosphate, autospongioplastics.