Aseptic necrosis of bone in caisson disease.

Caisson disease, or decompression sickness, is encountered when a raised atmospheric pressure on the body is reduced too rapidly and excess gases which have been held in solution in the blood and tissue fluids are set free as their solubility decreases. Typically the condition is manifested by tingling and paraesthesia, itching of the skin, and by bone and joint pains. The symptoms vary within wide limits, the majority being of a mild nature and in most instances relief is obtained by prompt recompression. The fact that permanent changes can take place in bone has, however, been recognized for some time. Twynam (1888) reported a case of necrosis of the shaft of the femur. Bassoe (1913) and Kahlstrom, Burton, and Phemister (1939a) described degenerative joint lesions with adjacent bony infarcts. Such lesions are not common. Ronald (1953) described infarcts involving the lower end of both femora, the upper end of both tibiae, and both humeral heads in a man who had been working as a diver for some 40 years. McCallum, Stanger, and Walder (1954) reported a case of necrosis of the femoral head in a caisson worker engaged in the construction of the Tyne tunnel. In reviewing the literature they found only two reports from Great Britain of bone infarction following decompression. One was in a caisson worker who died of acute cardiac ischaemia and at necropsy was found to have an avascular necrosis of both humeri (Swain, 1942). In the second report James (1945) gave an account of his findings in three of the five survivors of the ill-fated H.M. submarine Poseidon which sank after a collision in 120 ft. of water in 1931. The survivors escaped by use of the Davis apparatus and suffered in varying degree from " bends " immediately or shortly after surfacing. When examined 12 years later one had a lesion of the left humeral head, another had both femoral heads involved, while the third had an infarct of the left hip and left shoulder. In view of the rarity of this complication of caisson disease the following case may be of interest.