Radio-isotopic joint scans in haemophilic arthritis.

The majority of severe haemophiliacs will develop a crippling arthritis consequent upon recurrent haemarthroses although the pathogenic mechanism remains unclear. We have carried out technetium-99 pertechnetate joint scans in the elbows, knees and ankles of 23 haemophilic patients and compared the isotope uptake of the 15 patients with clinical and radiological evidence of arthritis to that of eight patients without arthritis, to 13 age-matched healthy male controls, and to 10 age-matched males with active rheumatoid arthritis. Isotope uptake into the knee joints was significantly higher in haemophilic arthritis than in controls, haemophiliacs without arthritis, and patients with rheumatoid arthritis [median percentage uptake of administered technetium (Tc) dose X 10(3) in right knee = 9.4, 6.2, 6.4 and 6.6, respectively]: and the differences from haemophilic arthritis were all significant (p less than 0.01, Mann-Whitney U test). Similar differences were seen in the elbows and ankles. Increased Tc uptake correlated strongly with frequency of haemarthrosis, pain, synovitis, range of movement and radiological changes in knees and elbows, but poorly with the lesser changes seen in the ankles. These results would support the theory that haemophilic arthritis amongst the inflammatory arthropathies and that scanning is an appropriate technique for following progression of joint disease.