[Morphological, morphometric and stereological aspects of Blount's unilateral stapling of the growth plate in animal experiments].

Medial stapling of the proximal tibial growth plate in ten-week-old pigs effects in the first instance a local reaction of the growth plate being first limited to the region between the staple branches. From the 4th-5th postoperative day on, there is a significant decrease of the growth rate, the surface area of cells in the zone of opening cells, and of the surface density of the adjacent metaphyseal spongiosa. From the 10th-11th day after stapling a significant decrease in the height of the metaphyseal columns and the growth plate occurs in the medial compartment as well as a trabecular broadening of the metaphyseal spongiosa in the stapled area. Subsequently, the surface density of the metaphyseal spongiosa is significantly lower, the volume density significantly higher than the control values. With advancing postoperative interval the stapling effects involve the whole growth plate. However, the central and the lateral compartments show always less distinct findings. Unilateral stapling of the growth plate brings about a significant diminution of the radiologically determined length of the epiphysis, metaphysis and the total tibia as well as an evident broadening of the growth plate.