Left knee pain, prior ACL repair MENISCI: The posterior horn of the medial meniscus is abnormally small which may reflect interval tearing or postmeniscectomy changes. There is abnormal signal within the posterior horn of the medial meniscus near its free edge which extends to both articular surfaces and is suspicious for an oblique tear. Additionally, there is blunting of the free edge of the body which may also reflect interval tearing or meniscectomy changes. A subcentimeter ovoid focus of low signal intensity is noted along the periphery of the meniscus at the junction of the body and posterior horn which is suspicious for a displaced meniscal fragment.There is attenuation of the anterior horn of the lateral meniscus but no discrete meniscal tear is identified.ARTICULAR CARTILAGE AND BONE: There is mild depression of the articular surface of the lateral femoral condyle at the level of the posterior horn of the meniscus which is thought to relate to an impaction fracture sustained at the time of initial ACL injury. There is degenerative thinning of the overlying lateral femoral cartilage but no fluid-filled articular cartilage defects are identified in medial, lateral, or patellofemoral compartments.LIGAMENTS: There are surgical changes relating to ACL repair. The ACL graft appears slightly thickened but is otherwise intact. A small focus of low signal intensity is noted within the joint space anterior to the graft which may reflect a small area of arthrofibrosis (cyclops lesion). The remaining ligamentous structures of the knee are intact.EXTENSOR MECHANISM: A small amount of edema is noted within the superolateral corner of Hoffa's fat pad. The Insall-Salvati ratio is 1.2 (borderline). There is slight prominence of the lateral femoral condyle anteriorly which may reflect a component of mild dysplasia. The tibial tuberosity to trochlear distance is 14 mm which is within normal limits. There is slight lateral translation of the patella in relation to the trochlea.ADDITIONAL
1. Slight thickening of the ACL graft which is otherwise intact. An area of low signal intensity is noted anterior to the graft which may represent a small focus of arthrofibrosis (cyclops lesion).2. Abnormal morphology of the medial meniscus which could in part be related to prior meniscectomy changes; however tearing of the meniscus with a displaced fragment is suspected as described above.3. Additional findings as described above.