[Bone marrow edema syndrome (BMES)]

Bone marrow edema (BME) syndrome represents a pathologic accumulation of interstitial fluid in bone - with a traumatic BME being differentiated from a non-traumatic, often ischemic, and a reactive as well as a mechanical BME. Atraumatic/ischemic BME is inconsistently described as a separate entity or as a reversible preliminary stage of osteonecrosis (ON). However, there is always the risk of transformation of BME into ON and subsequent joint destruction. The most common sites of BME are the hip, knee, and ankle. Magnetic resonance imaging is the diagnostic gold standard. Differential diagnoses of the transient BME as osteonecrosis, osteochondrosis dissecans, and a reflex dystrophy should be considered. Conservative or surgical treatment is considered, depending on the etiology of BME. BME syndrome is generally treated conservatively. Infusion of prostacycline or bisphosphonates is a promising option. Ischemic BME and early stages of ON can be successfully treated by core decompression. A combination of both treatment options may also offer advantages.