Osteochondral avulsion of patellar cartilage at the medial articular facet with fragmentation and displacement lateral to lateral femoral condyle anterior to popliteus tendon insertion.
Associated high-grade partial thickness tear of medial patellar retinaculum.
Bone marrow oedema of the inferomedial aspect of the patella and anterolateral aspect of the lateral femoral condyle.
Moderate knee joint effusion, with three different intensity layers reflecting lipohaemarthrosis.
Traumatic changes of Hoffa pad of fat.
Wiberg type I patella and no trochlear dysplasia.
Intact cruciate ligaments, collateral ligaments and menisci.