[Results of fluorescence microscopy studies of bone healing by direct stimulation with bipolar impulse currents and with the interference current procedure in the animal experiment].

42 cross-breed rabbit bastards of either sex were osteotomized on the left proximal third of the tibia. A teflonisolated stable plating was made by means of the polychromatically KF-AO-instrumentarium. The animals were fluorescentlabelled in weekly intervals. Tetraverinex, alizarin complexon, fluorexon, xylenol orange and calceine were used as colours. The animals were stimulated in the bipolar squaretopped pulse current procedure (1 Hz and 10 Hz, resp., +/- 25 and +/- 50 microA, resp., intensity, permanent stimulation) or in the interference current procedure (oscillation frequency 100 Hz, intensity 1 mA, 4 hours daily). An osteotomized group served as a control. The undecalcified bone sections were quantitatively measured in the area of the periosteal and endoosteal accummulation seams as well as in the area of the Haversians canals and compared by means of multiple variance analyses. A delay in the Haversian remodelling within the first 2 weeks was found in the animals only osteotomized. This delay could not be detected in all electrically stimulated groups. The electrical stimulation leads to a shortening of the fracture healing period by skipping the physiologically occurring delay of the Haversian remodelling in fractures and osteotomies. Further on there was derived a growth function of the osteones as a regression function r (t) = a + beta X e gamma t. For the rabbit the concrete formula expression r (t) = 50.9 X e-0.094 X t + 17.4 for the animals not treated and r (t) = 42.9 X e-0.067 X t + 8.5 for the electrical stimulated animals has been found.(ABSTRACT TRUNCATED AT 250 WORDS)