Atraumatisches Knochenmarködem des Kniegelenks

Bone marrow edema (BME) represents a magnetic resonance imaging (MRI) phenomenon characterized by hypointensity on T1-weighted images and hyperintensity on short tau inversion recovery (STIR) sequences or fat-suppressed T2-weighted images. The BME syndrome is a clinical radiological entity in which transient, nonspecific, subacute or chronic joint pain occurs with characteristic MRI findings but without specific secondary causes. The pathophysiology is thought to be the result of venous outflow obstruction leading to edema, increased intraosseous pressure and ultimately impaired arterial inflow, resulting in intraosseous ischemia and necrosis. Generally, BME is considered self-limiting over a period of 3–18 months. Treatment approaches primarily include unloading the affected joint for 6–8 weeks, depending on the symptoms and radiological follow-up. Supportively, pain and anti-inflammatory medications can be taken. Other conservative treatment approaches include extracorporeal shock waves or pulsed electromagnetic fields as well as pharmacological treatment such as the off-label use of bisphosphonates, prostacyclin analogs and denosumab. Surgical interventions including core decompression, percutaneous drilling or subchondroplasty should only be considered in cases where conservative treatment has failed.