Patient was pregnant (first trimester) so contrast was being withheld.
Haemarthrosis containing multiple fluid- fluid levels.
Pathological fracture through the lesion in the distal femoral metaphysis extending into the epiphysis, but not extending to the articular surface. Lesion is centred eccentrically in the medullary cavity.
Lesion abuts and thins the medial and posterior cortices of the distal femoral metaphysis.
No evidence of cortical destruction. No definite soft tissue tumour component. Extensive medial soft tissue oedema extends deep to the vastus medialis to the junction of the middle and distal thirds of the femur.
There is heterogeneous signal within the lesion - predominantly T2 hyperintense, T1 hypointense - but not signal of completely simple fluid. No evidence of osteoid or chondroid matrix.
Fracture line extends through the medial cortex distal femoral metaphysis to the intercondylar notch.
Minimal posterosuperior displacement of the fracture fragment.Minor marrow oedema in the medial femoral condyle. Note is made of a horizontal tear of the posterior horn of the medial meniscus.
Pathological fracture through lesion in distal femoral metaphysis.
Heterogeneous material in the lesion may represent acute haemorrhage into fluid in the context of simple bone cyst (note is made of the fallen fragment on CT). A more aggressive lesions such as a metastasis or primary bone sarcoma are less likely. The lesion does not extend to subchondral bone and does not have the signal intensity of a giant cell tumour.