Bone marrow edema is a common cause of pain of the locomotor apparatus. We reviewed 50 patients (28 male, 22 female) with bone marrow edema of the knee. The patients mean age was 56.2 12.8 years. 8 cases were estimated to have an idiopathic BME, 10 posttraumatic and the other 32 ones to be secondary to an activated osteoarthritis or to mechanic stress. Iloprost is a vasoactive prostacyclin analogue. Therapy consisted of a series of five infusions with either 20 or 50g of iloprost given over 6 hours on 5 consecutive days each. Pain at rest as well as under stress were assessed with a semi quantitative scale from before and 4 months after therapy. MRI investigations were done before and repeated 4 months after therapy.

At the clinical follow-up 4 months after therapy, pain level at rest had diminished 84% (p < 0.0001). 70% of patients referred about a reduction, 30% about no change. Pain under stress decreased 57%, (p < 0.0001). 76% of patients showed lower pain under activity, 24% no change from baseline. There was no increase of pain level in any patient. In MRI in 85% a significant reduction of the BME size or complete restitution could be observed, 15% showed no change. Response rate to iloprost infusions came to 100% in idiopathic, 100% in posttraumatic and 66% in secondary BME. A significant reduction of side effects could be reached by lowering the daily dosage from 50 to 20g.

The authors conclude that parenteral application of iloprost might be a viable method in the treatment of BME of different origins.