Nogah Shabshin MD, Presenter: Nothing to Disclose

Ran Thein MD, Abstract Co-Author: Nothing to Disclose

Mark E. Schweitzer MD, Abstract Co-Author: Nothing to Disclose

Gina Anna Di Primio MD, Abstract Co-Author: Nothing to Disclose

Bone marrow edema around the knee in young adults is most frequently seen following trauma. We present a series of an unusual pattern of marrow edema in the medial femoral condyle that is likely self inflicted traumatic in “risk adverse” young military recruits.

Nine military recruits (8 males: 1 female; 19-24 years), underwent 3T MRI for further investigation of knee pain. These patients either presented with atypical symptoms, non-specific pain or failure to respond to usual therapy. They all showed marrow edema in the medial femoral condyle. Two observers evaluated the location of marrow edema within the medial condyle, distance from articular surface, dimensions, overlying soft tissue abnormality and internal derangements. Clinical history was obtained from medical records.

The edema was always subcortical, either mid (6) or mid-anterior (3) but never centered at the subarticular condyle. The size of the “bruise” was 8x10x8mm to 32x46 x40mm. Overlying soft tissue abnormalities were common (4/9) and included organizing (1/9) or residual hematoma (3/9). Concomitant MR abnormalities were seen in only 3/9 and were usually minor or subtle. Seven patients complained of longstanding pain without antecedent trauma, and 2 reported remote trauma. Patients had atypical physical examinations and were felt clinically to have low motivation algoagnia. One patient had a negative follow-up MR at 4 months. We found soldiers' chat-rooms where a mechanism for direct self induced trauma to the medial distal femur was demonstrated.

We describe an unusual MR-pattern of edema in the medial femoral condyle in military recruits. The combination of appearance, location and clinical history is suspicious for self infliction.

When marrow edema is seen in the anterior middle aspect of the medial femoral condyle above the joint that is inconsistent with the known patterns consider self infliction for secondary gain purposes.

Shabshin, N, Thein, R, Schweitzer, M, Di Primio, G, Atypical Pattern of Bone Marrow Edema in the Medial Femoral Condyle of Military Recruits: Is It Related to Repetitive Self-induced Trauma?.  Radiological Society of North America 2010 Scientific Assembly and Annual Meeting, November 28 - December 3, 2010 ,Chicago IL. http://archive.rsna.org/2010/9009267.html