MRI Appearance of Presumed Self-inflicted Trauma in the Knees of Military Recruits

Thein, Ran MD
Schweitzer, Mark E. MD
Diprimio, Gina MD
Shabshin, Nogah MD

Dr Thein is from the Department of Orthopedics, Chaim Sheba Medical Center, Tel HaShomer, Israel; Drs Schweitzer and Diprimio are from the Department of Diagnostic Imaging, The Ottawa Hospital and University of Ottawa, Ottawa, Canada; and Dr Shabshin is from the Department of Radiology, Hospital of the University of Pennsylvania, Philadelphia, Pennsylvania, and the Department of Diagnostic Imaging, Asutta Medical Center, Tel Aviv, Israel.

Drs Thein, Schweitzer, Diprimio, and Shabshin have no relevant financial relationships to disclose.

This study was performed at Chaim Sheba Medical Center, Tel HaShomer, Israel.

Correspondence should be addressed to: Ran Thein, MD, Department of Orthopedics, Chaim Sheba Medical Center, Tel HaShomer, Israel 52621 ( [email protected]).

Orthopedics 35(5):p e691-e696, May 01, 2012. | DOI: 10.3928/01477447-20120426-23

When knee bone marrow edema is observed on magnetic resonance imaging (MRI), it usually follows a pattern that can be explained by certain etiologies. This article describes a series of unusual knee bone marrow edemas in soldiers presumed to represent self-inflicted trauma.

Ten soldiers (9 men and 1 woman; age range, 19–24 years) underwent knee MRI. None reported recent trauma or stress, and all presented with nonspecific pain or failure to respond to therapy. All showed a similar unusual pattern of bone marrow edema in the medial femoral condyle. Three observers evaluated the location of the bone marrow edema within the medial femoral condyle and its distance from the articular surface, dimensions, overlying soft tissue abnormality, and internal derangements. The edema was always subcortical and located in the middle aspect (n=7) or mid-anterior aspect (n=3) of the medial femoral condyle but was never centered subarticularly. Edema size ranged between 8×10×8 and 32×46×40 mm. Overlying soft tissue abnormalities were common (n=4) and included organizing (n=1) and residual hematoma (n=3). Concomitant MRI abnormalities were seen in 3 patients, usually minor. Eight patients reported longstanding pain with no antecedent trauma, and 2 reported remote trauma. One patient had a negative 4-month follow-up MRI, and another had a negative arthroscopy. Poor correlation existed between MRI findings and the absence of stress and trauma. Soldier chat rooms were found that describe how to induce fractures at this location.