PROSTAGLANDIN RELEASE FROM RAT FEMURS AFTER IMPLANTATION OF HYDROXYLAPATITE AND ALUMINUM-OXIDE CERAMICS

The bony reaction after implantation of uncemented ceramics is of spec ial interest, Therefore porous and dense hydroxylapatite and aluminium oxide ceramics were implanted in rat femurs, One group received no su rgical manipulation and another with a sham procedure where no ceramic s were implanted served as controls, After 6 and 10 days the rat femur s were harvested and the release of PGE(2) and 6-keto-PGF(1 alpha) was measured with specific radioimmunoassays, Decrease in the release of PGE(2) from day 6 to day 10 was present in all three implants, In cont rast, 6-keto-PGF(1 alpha) increased from day 6 to day 10. Comparing th e ceramic types an increase in 6-keto-PGF(1 alpha), release was seen i n the porous hydroxylapatite group. These prostaglandin (PG) release p atterns after ceramic implantation are similar to those of fracture he aling, but aluminium oxide seems to be inert, while hydroxylapatite, e specially the porous type, stimulates 6-keto-PGF(1 alpha) release.