35-year-old male patient with positive Lachman's and intermittent locking. Question of ACL tear, meniscal tear. MENISCI: Vertical increased signal abnormality within the posterior horn of the lateral meniscus represents a tear. Additionally, there is increased, multidirectional signal within the anterior horn/root of the lateral meniscus which likely represents a complex tear or contusion of the root. The medial meniscus appears intact.ARTICULAR CARTILAGE AND BONE: There is slight cortical depression of the weightbearing portion of the lateral femoral condyle without underlying edema which suggests a prior impaction injury. Additionally, the overlying cartilage is thinned. Otherwise the articular cartilage of the medial tibiofemoral compartment and patellofemoral compartment appears intact.LIGAMENTS: There appears to be a avulsion of the anterior cruciate ligament from its tibial attachment with the fracture fragment of the tibial spines lying within the intercondylar notch measuring approximately 8 mm.Edema is also noted within the tibia underlying the site of prior attachment. The posterior cruciate ligament appears intact. The collateral ligaments appear intact.EXTENSOR MECHANISM: The extensor mechanism is intact.ADDITIONAL
Findings compatible with a pivot-shift mechanism of injury with ACL tibial avulsion injury.Recommend plain film radiographs or CT to further evaluate the tibial spine avulsion. Tearing of the lateral meniscus (as above), and evidence of lateral femoral condyle impaction injury.