RESUMO
The effects of various degrees of cold injury upon bone growth were experimentally studied. Young rabbits' feet, rendered ischemic by the application of a tourniquet, were cooled down by immersion in either an ice bath at 0 degrees C or an alcohol bath at -20 degrees C. The bone injuries were assessed clinically, radiologically, and histologically. Prolonged exposures to low temperatures above freezing do not cause any bone damage. Brief exposures to temperatures between -20 degrees C and -15 degrees C affect bone growth by inducing premature arrest of the epiphyseal plate, destruction of the epiphysis, and reactive-endosteal and periosteal bone formation. These effects lead to a statistically significant shortening and widening of the affected bones, which can be demonstrated radiologically. Low temperatures have a primary direct lethal effect upon the highly sensitive chondrocytes of the epiphyseal growth plate. Bone damage is independent of associated soft-tissue injuries and not linked to frostbite of the extremity or to solidification of tissues.
