[Results of application of hydroxyapatite and hydroxyapatitecollagen.]. / Výsledky pouzitia hydroxyapatitu a hydroxyapatitkolagénu na výpln kostných defektov.

The authors present their experience of the application of hydroxyapatite and a composite-hydroxyapatitecollagen in 2 groups of patients. In the first group they evaluate the mediumterm results in 10 girls and 8 boys of average age of 12,5 years after the filling of bone defects in case of bone cysts, aneurysmatic cysts, fibrous cortical defect and eosinophilous granuloma. Hydroxyapatite was applied in the form of rolls, small bricks, strips. The first signs of healing were evident as early as after 4 months, after 36 months osteointegration was practically finished. In the second group of 1995-2000 period they applied hydroxyapatite in 15 patients of average age of 45 years. In this group they applied the mentioned biomaterial also in 6 patients with instabilities and primary and secondary (metastasis) bone tumours on the spine where they also achieved after a shorter follow-up of 6-8 months good osteoinductive and conductive qualities of the biomaterial. The authors point out the two biggest contributions in this respect: filling of bone cavities with an unusually big amount of hydroxyapatite (up to 70 g) and good, even though only short-term results after resection and filling of malignant bone tumours. Key words: hydroxyapatite, collagen, osteoinduction, osteoconduction, bone defects.

[Atelocollagen/hydroxylapatite composite material as bone defect filler in an experiment on rats]. / Kompozit atelokolagén-hydroxylapatit ako výpln kostných defektov v pokuse na potkanoch.

Many types of biomaterials are used as skeletal bone fillers in reconstructive surgery. An attention is paid to hydroxyapatite due to its high biocompatibility with the surrounding tissue. The paper deals with the testing of new collagen/hydroxyapatite composite material applied to the bone defect on os parietale of rats. The composite material was prepared from the bovine atelocollagen dispersion and the dispersion of hydroxyapatite. Collagen serves as a matrix in which the particles of hydroxyapatite are anchored. The composite presents the advantage that after the saturation with physiological solution it is compact and can be shaped. The composite material was implanted in the form of plate into six male Wistar rats to the ground bed on the surface of os parietale. The implants were taken out after four moths. The macroscopic finding of soft tissue, bones and implants gave evidence about good healing without any undesirable reaction. This was also confirmed by the histological observations. Collagen was resorbed and the rest of the material strongly adhered to the bone. The marked osteocytes were present in the zone of the newly formed bone and the dividing line between new and old bone was clear. The experimental results give preconditions to the clinical use of this new composite implant material the structural improvement of which is in progress. (Fig. 2, Ref. 12.)