14-year-old male with left knee pain

Patellofemoral joint alignment demonstrates mild lateral patellar tilt with a thinned attenuated medial patellofemoral ligament with partial-thickness tearing at its insertion upon the patella and at its origin from the medial femoral condyle. No substantive patellofemoral chondromalacia. Quadriceps and patellar tendons are intact. Moderate-sized joint effusion mildly complex likely reflecting a component of hemarthrosis. No Baker’s cyst.
 
Near full-thickness tearing of the medial collateral ligament proper. Partial-thickness tear of the meniscofemoral attachment. Prominent edema and hemorrhage are noted surrounding the medial collateral ligament complex. Partial-thickness tearing of the fibular collateral ligament with surrounding edema consistent with a grade 2 LCL sprain. No evidence of macrofracture. Microtrabecular fracture along the lateral femoral sulcus with mild depression and along the posterolateral tibial plateau without substantive depression consistent with a pivot shift mechanism of injury. Mild edema along the tip of the fibula likely reflecting stress reaction from posterolateral corner injury. Vertical posterior 2cm meniscocapsular sprain posterolateral horn.
 
Full-thickness ACL rupture with surrounding edema and hemorrhage. PCL is intact.
 
No medial meniscal tear or discoid meniscus. No substantive medial compartment chondromalacia. No lateral meniscal tear or discoid meniscus. No substantive lateral compartment chondromalacia.
 
Prominent hemorrhage and edema noted extending along the popliteus tendon at the posterolateral corner. The superior and inferior popliteomeniscal fascicles are not well visualized and likely torn. Partial-thickness interstitial tearing of the popliteofibular ligament. Partial-thickness tearing of the arcuate ligament posteriorly. Tear of the lower meniscopopliteal segment.