• Call us (213) 742-1000
  • donate


Joint bleeding is the hallmark of patients suffering from hemophilia. Even though this bleeding can occur in any joint space, the most commonly affected joints are the knees, elbows and ankles.  At one time, hemophilic patients crippled with chronic joint bleeding and synovitis (inflamed joint membranes) simply had to suffer with little or no relief.

Today, patients can undergo a minimally-invasive procedure called a radiosynovectomy to control joint bleeding, relieve pain and regain mobility. Although it has been generally accepted that recurrent bleeding inside the joints leads to degenerative changes, the precise mechanisms by which this phenomenon occurs have remained unclear. It is likely that the pathophysiology of hemophilic arthropathy has many causes and involves synovium- and cartilage-mediated components.

Radiosynovectomy involves the injection of radioactive material into a joint, is an alternative to surgical syncovectomy for decreasing the activity of hemophilic synovium (see Joint Damage). The radioactive particles injected into the synovium cause a reduction in the thickness of the synovium and consequently the cycle of bleeding into the joint cavity.

Compared with open and arthroscopic synovectomies, radiosynovectomy has the advantage of being a minimally invasive outpatient procedure that has a modest clotting-factor requirement, even in patients with inhibitors (antibodies that prevent clotting factor from working). It is also relatively inexpensive procedure, with costs reported to be significantly lower than surgical syncovectomies.

Success rates for radiosynovectomy are similar to surgical synovectomies, with radiosynovectomy decreasing the frequency of joint bleeding by a reported 75% to 100%.

Additionally, radiosynovectomy preserves joint range of motion better than open or arthroscopic synovectomy.

OHTC began performing radiosynovectomy in 1988 and close to 340 procedures have been done in patients with moderate and severe hemophilia to date. 


The primary safety concern with radiosynovectomy is exposure of non-synovial tissue to ionizing radiation. Leakage of the radioisotope from treated joints could potentially accumulate in regional lymph nodes, the reticuloendothelial system (part of the immune system that clears abnormal and old cells), bone marrow and liver. The degree and impact of leakage is influenced by the size and physical properties of the radionuclide particle. The large size of radioactive P-32 particles is associated with insignificant leakage rates.

In OHTC’s experience, only one of 98 patients in whom isotope distribution data was available demonstrated extra-articular radiation levels above those of the background.