A double-blind study of erbium169 synoviorthesis in rheumatoid digital joints. Results after one year.

A double-blind study was made on the effectivenss of erbium169 synoviorthesis in the digital joints of 7 patients with erosive, seropositive rheumatoid arthritis. The study involved 70 joints observed over a 12-month period: 20 pairs of metacarpophalangeal joints (MCP) and 15 pairs of proximal interphalangeal joints (PIP) were injected with erbium169 in one joint and saline in the other one. All joints had radiological lesions corresponding to State I and II of the Steinbroker classification. Six months after synoviorthesis, good and excellent results were observed in 71% of the articulations treated with erbium169 and in only 40% of those injected with saline (placebo) (p less than 0.01). Good and excellent results were noted in 79% of the joints treated with the isotope after one year, compared with only 50% injected with the placebo (p less than 0.05). The beneficial effect of erbium169 synoviorthesis on the pain and inflammatory phenomena of rheumatoid digital joints is therefore proven. Occasionally the isotope causes a slight decrease in the range of movement of the treated joint.