Axial PD-weighted TSE MRI of a 41-year-old female with a first LPD. At the medial facet of the patella, a full-thickness defect of the cartilage (grade 4) with fracture of the subchondral bone (long white arrow) and a free cartilage fragment (long black arrow) is visible. Furthermore, a full thickness cartilage defect at the central dome of the patella (short black arrows) is depicted. MR imaging of chondral or osteochondral fragments, cortical steps or bone destructions provides additional information when planning surgery, such as a refixation.