53-year-old male patient status post patellar dislocation. Assess MPFL. MENISCI: The lateral and medial menisci are intact.ARTICULAR CARTILAGE AND BONE: There is full-thickness loss of the articular cartilage along the lateral facet of the patella. There is also increased signal intensity in the medial facet articular cartilage indicating degeneration. There is an approximately 1.5 cm focus of intermediate signal intensity within the medial aspect of the patellofemoral articulation which likely represents a displaced cartilage fragment. There is also a 1 cm crescentic osteochondral fragment centered about the anterior aspect of the medial femoral condyle. There is a full-thickness cartilaginous defect along the lateral femoral condyle just above the anterior horn of the lateral meniscus with mild edema-type signal in the underlying bone. Increased signal intensity within the articular cartilage of the weightbearing portion of the lateral tibial plateau likely reflects degeneration. The medial compartment articular cartilage is intact.LIGAMENTS: The cruciate ligaments, medial collateral ligament, and lateral collateral ligament complex are intact.The medial patellofemoral ligament is not well visualized, likely representing a tear, with fluid and edema along the medial retinacular structures of the knee.EXTENSOR MECHANISM: There is an incomplete tear of the quadriceps tendon at the insertion on the patella. This includes a full-thickness but minimally retracted tear of the vastus intermedius, a full-thickness but minimally retracted tear of the vastus medialis, and partial thickness longitudinal tearing of the rectus femoris. The fibers of the vastus lateralis tendon can be traced to the insertion on the patella, although the medial fibers may be partially torn. Small ossicles are seen within the distal quadriceps tendon.ADDITIONAL
Findings compatible with lateral patellar dislocation as described above. The medial patellofemoral ligament is not well seen and likely torn. Furthermore, there is tearing of the distal quadriceps tendon as described above and cartilage defects with fragments in the joint.