Caisson disease of bone: a study of the Göttingen mini-pig as an animal model.

Investigation of the exact aetiology, early diagnosis and prevention of caisson disease of bone has been hindered by the inability to produce, by the use of realistic compression/decompression exposures, truly comparable lesions in animals. Four Gottingen mini-pigs were subjected to repeated exposures to pressures of 27 p.s.i.g. for 6 h over a period of 9 months and decompressed according to standard tables. Two mini-pigs acted as controls. In one animal radiological changes were recognised in the left lower femoral shaft 19 weeks after the exposures were started and subsequent examination of that bone confirmed the presence, at that site, of a lesion which macroscopically and microscopically resembled, in every way, the appearances of those seen in the shafts of long bones in man. It is concluded therefore that, properly used, the mini-pig may be a suitable animal model for the study of this condition in man.