Right knee pain. Evaluate for meniscal injury. There is susceptibility artifact from an intramedullary rod and anchoring within the femur extending to the metaphysis and limiting evaluation in this area.MENISCI: There is blunting of the free edge of the medial meniscus which otherwise appears intact. Globular high T2 signal within the anterior horn of the lateral meniscus which does not extend to the articular surface and is compatible with intrasubstance degeneration. There is branching linear signal within the posterior horn and body of the lateral meniscus which likely represents a combination of prior tear, postsurgical change and degeneration. There is no evidence of acute, new tear however, there is increasing extrusion of the lateral meniscus.ARTICULAR CARTILAGE AND BONE: The articular cartilage in the medial compartment is thinned and there is full-thickness loss along the anterior aspect of the femoral condyle spanning an AP image of 9 mm (series 1, image 9).Full thickness cartilage degeneration is seen along the posterior aspect of the lateral femoral condyle and has progressed since the previous exam. There is a fissure along the weightbearing of the lateral femoral condyle surface with delamination extending over an AP dimension of 7 mm and underlying reactive marrow change.Cartilage degeneration has progressed in the patellofemoral compartment where there is mild fraying of the patellar cartilage but full thickness degeneration along the femoral trochlea.No acute fracture. There are post surgical changes from prior anterior cruciate ligament reconstruction.LIGAMENTS: Status post anterior cruciate ligament reconstruction. There is linear high T2 signal within the ACL graft fibers near its tibial attachment which raises question of a small split tear however the graft otherwise appears intact. The posterior cruciate and medial collateral ligaments are intact. The fibular collateral ligament appears mildly redundant without evidence of discrete tear or acute abnormality.EXTENSOR MECHANISM: The extensor mechanism is intact. There is a small amount of nonspecific prepatellar edema.ADDITIONAL
1.Branching linear signal within the posterior horn and body of the lateral meniscus likely represents a combination of prior tear, postsurgical change and degeneration. There is increased extrusion of the lateral meniscus but no evidence of new, acute tear.2.Progression of cartilage degeneration with full-thickness loss over the lateral femoral condyle and femoral trochlea.3.Intact ACL graft.4.Small joint effusion with synovitis.