Presentation
Knee pain without history of any trauma.
Patient Data
A focal area of bone marrow edema and subtle flattening of the medial femoral condyle is noted along with irregular hypointense line in subchondral region representing granulation tissue/callus formation. Overall features are compatible with spontaneous osteonecrosis of the knee (SONK).
Linear high T2/PD fat sat horizontal oblique high signal intensity is noted within posterior horn of the medial meniscus reaching the articular surface representing a horizontal meniscal tear.
Case Discussion
Spontaneous osteonecrosis of the knee joint mainly involves the medial femoral condyle. Localized vascular insufficiency is presumed to play role in necrosis and subsequent disruption of the nutrition supply to the above cartilage.
Dr. Farhad Farzam has also contributed to this case.