Following a fall and injury to the left knee, this 12-year-old boy has been having pain in that knee with difficulty in walking. The knee was swollen, painful with restricted movements. There was no redness or warmth.
The MRI shows multiple dilated tubular flow voids in the Hoffa’s fat pad with adjacent PDFS hyperintensity over the anteromedial aspect of the lateral tibial plateau. The feeding artery is the lateral geniculate branch of the popliteal artery. The veins drain in the subcutaneous plane along the lateral femoral condyle. The joint space, articular cartilage and underlying bones are normal. The angiogram confirms these findings as a high flow AVM.