Figure 19. Recent patellar dislocation. (a) Sagittal short tau inversion recovery image shows oedema adjacent the lateral aspect of the lateral femoral condyle (arrow). (b) Axial image showing a large defect in the retropatellar cartilage (arrow). An articular cartilage fragment is embedded in the synovium of the lateral recess (open arrow). There is widening of the medial retinaculum (*).