THE CLEARANCE OF NA24 FROM THE NORMAL AND OSTEO-ARTHRITIC KNEE JOINT AND THE RESPONSE TO INTRA-ARTERIAL PRISCOLINE®1

Abstract

The status of the local circulatory bed in degenerative joint disease was investigated by determining the average clearance of Na24 from 13 subjects with normal knee joints and from 53 patients with degenerative joint disease of the knee. The latter were divided into 2 groups, i.e. those with normal X-rays or minimal changes roentgenologically, and those with moderate to severe changes. We determined the significance of differences between the average clearance for normals and that for all patients, between the normals and each of the 2 groups of patients, and between the 2 groups of patients. The differences in clearance rates in the several groups were statistically significant. In normal subjects the initial rate of clearance of Na24 was slow but increased sharply following intra-arterial Priscoline (2-benzyl-2-imidazoline). In patients with distinct roentgen changes, initial Na24 clearance was generally rapid and did not increase following Priscoline. Where X-ray change was absent or minimal the average clearance constant was rapid compared to normal and the response to Priscoline was moderate. We believe we have demonstrated that as degenerative changes progress within a joint, the degree of vasodilatation present becomes greater, but with the consequence that, when necessary, further increase in circulation is not possible.