Proposal of early retreatment with iloprost in partially responsive patients with bone marrow edema syndrome: a case report

Background
Avascular Necrosis (AVN) is defined as the cellular death of bone components due to an alteration of the blood supply, resulting in Edema of the Bone Marrow (BME), structural collapse and bone destruction. In advanced stages, AVN requires surgery. One emerging medical treatment for supporting osseous perfusion is the administration of iloprost.

Materials and methods
A 38-year-old woman presented with severe BME of the left hip (primary), persisting for 6 weeks. She was treated with iloprost iv at 2 ng/kg/min for 6 hours/day for 5 days, and after 4 weeks, the treatment was repeated at 1.5 ng/kg/min for 6 hours for 5 days because she exhibited only a partial response to the first treatment. Complete remission was obtained, documented clinically and on Magnetic Resonance Imaging (MRI). Her Harris Hip Score (HHS) increased from 29.90 to 97. No significant adverse events related to iloprost were registered. No surgical procedures were necessary.

Conclusions
In most cases, iloprost is administered in a single cycle of treatment over 5 days at 1-2 ng/kg/min for 6 hours/day, but no research has investigated the effectiveness of early retreatment after the first cycle results in only a partially response. Only a few studies examining small numbers of patients have evaluated iloprost in AVN/BME, preferring, in most cases, the dose of 1 ng/kg/min and obtaining clinical improvement both in BME and in AVN in times comparable to surgical core decompression. This case report demonstrates the safety and effectiveness of early repetition of the maximal dose of iloprost before BME evolves into AVN, as well as in cases initially appearing serious and requiring surgical procedures.