Reason: Left Knee instability, r/o ACL and or LCL tear History: knee instability MENISCI: The medial meniscus is unremarkable. The anterior horn and body of the lateral meniscus is unremarkable. There is an obliquely oriented vertical signal abnormality within the peripheral third of the posterior horn of the lateral meniscus which extends to the tibial articular surface and is continuous with the interface of the meniscus with the meniscofemoral ligament of Wrisberg. While we can't entire exclude the possibility of a meniscal tear, we suspect that it may simply represent a far lateral continuation of this normal variant interface.ARTICULAR CARTILAGE AND BONE: There is slight heterogeneity in the hyaline cartilage of the patella, suggesting mild degeneration, as well as slight heterogeneity of the articular cartilage of the lateral femoral trochlea, likely representing focal degeneration, with mild focal edema in the underlying bone. The articular cartilage in the tibiofemoral compartments is within normal limits.LIGAMENTS: The anterior cruciate and posterior cruciate ligaments are within normal limits. The medial and lateral collateral ligament complexes are unremarkable.EXTENSOR MECHANISM: There is mild thickening of the proximal patellar tendon with small ossicles as seen on prior radiographs, perhaps representing mild chronic tendinosis or sequela of Sinding-Larsen-Johansson syndrome. The Insall-Salvati ratio is within normal limits. The superior aspect of the medial femoral trochlea appears hypoplastic relative to the lateral aspect, suggesting dysplasia. Furthermore, the tibial tuberosity to trochlear groove distance is approximately 18 mm, which is borderline abnormal. There is slight lateral translation of the patella with respect to the center of the trochlea as well as edema within the superolateral aspect of Hoffa's fat pad, suggesting patellofemoral instability.ADDITIONAL
1.Findings indicative of patellofemoral instability as described above.2.No evidence of ACL or LCL tear.3.Linear signal abnormality in the posterior horn of the lateral meniscus is felt more likely to reflect a prominent interface with the ligament of Wrisberg rather than a true tear.