From clinical observations it appears that the roentgen irradiation affects the cellular changes of Marie-Strümpell arthritis, but we have no evidence that. it affects the associated ossifying process once it is under way.

In a series of 100 patients with Marie-Strümpell arthritis, treated by roentgenotherapy plus corrective measures, the results, based on relief of pain, range of motion, and roentgenographic changes, indicate that the therapy can be expected to give approximately the same relief from pain during any stage of the disease. Increase in range of motion can be expected in a fair percentage of the mild and moderately advanced cases. Although there is relief from pain, a decrease in range of motion and further ossification may occur. In the mild or moderately advanced cases, the process can be arrested and in some instances cleared by the roentgenotherapy. Of the forty-seven patients in the mild and moderately advanced groups, fifteen showed roentgenographic clearing of the bone changes; twenty-four sholved no change or advance in the disease; only seven showed advance with additional ossification. Comparison with the advanced group of thirty-two patients shows that roentgenographic improvement can be expected in the earlier cases more frequently than in the advanced cases, where the changes are no longer reversible.