Experimentally induced osteonecrosis in miniature swine.
Dysbarism-related osteonecrosis: proceedings of a symposium on dysbaric osteonecrosis. Beckman EL, Elliott DH, eds. Cincinnati, OH: U.S. Department of Health, Education, and Welfare, Public Health Service, Centers for Disease Control, National Institute for Occupational Safety and Health, DHEW (NIOSH) Publication No. 75-153, 1974 Jan; :105-111
Miniature swine were exposed to standard profiles of 60 feet sea water for 6 hours to study the incidence of osteonecrosis in relation to compression/decompression stress. The experiment called for a decompression rate of 30 feet per minute for 35 to 50 dives. After 25 to 30 dives the animals manifested signs of bends after each one, although they did not always require recompression. The decompression rate was reduced to 1.33 feet per minute. Even with this prolonged decompression period, dysbarism did occur in some. No significant changes occurred in red and white cell counts, hematocrit, hemoglobin, and reticulocyte counts. A decrease in postdive platelet counts was noted. Clotting, prothrombin, and partial thromboplastin times showed no significant changes. No changes were noted in uric-acid, alkaline-phosphatase, serum glutamic-oxaloacetic-transaminase, lactic-acid-dehydrogenase, calcium, and phosphorus levels. Creatine-phosphokinase measurements were routinely elevated as the number of exposures increased. Phospholipids, triglycerides, cholesterol, cholesterol esters, and total lipid values did not change. Radiographic studies showed the most profound consequence of these exposures to inadequate decompression profiles to be aseptic bone necrosis. The connection between bubble formation with alterations in the clotting mechanism and the resultant infarcts in the small vasculature supplying nutrition to bone cells was restated.
Laboratory-animals; Bone-disorders; Skeletal-stress; Skeletal-system-disorders; Hypobarism; Pressure-testing; Divers; Decompression-sickness; Caisson-disease; Blood-cells
Dysbarism-related osteonecrosis: proceedings of a symposium on dysbaric osteonecrosis