Based on previous experience in inflammatory arthritis, a small number of o
pen studies have evaluated the usefulness of chemical synoviorthesis with o
smic acid in haemophilia, with various assessment criteria and a wide range
of follow-up periods. Based on these studies, the efficacy of osmic acid s
eems modest, with 30-44% of good clinical and radiological results, but wit
h fair or poor clinical results in other patients with a possible deleterio
us effect on cartilage. Osmic acid was found inferior to Yttrium-90 in one
retrospective study. Synoviorthesis with osmic acid seems particularly indi
cated in haemophilic arthritis with no or mild radiological deterioration i
n children between 8 and 15 years of age. However, prospective randomized s
tudies are clearly required to evaluate the symptomatic and structural effe
cts of chemical and radioactive synoviorthesis in haemophilic arthritis.