What are the three main structures of the posterolateral ligamentous complex of the knee?
the lateral collateral ligament, the popliteus muscle and the popliteofibular ligament
Which other ligament injuries of the knee are commonly associated with lateral collateral ligament injuries?
Anterior and/or posterior cruciate ligament injuries or injuries to other posterolateral corner structures of the knee.
Findings
Bone
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a well-circumscribed lobulated lesion in the lateral femoral metaphysis (~22 x 17 x 11 mm) with internal foci of low signal, 'rings and arcs' characteristics and a narrow transition zone
Joint space
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mild to moderate knee joint effusion
Intercondylar region
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anterior and posterior cruciate ligaments
Medial compartment
articular cartilage intact
incomplete tear of the posterior horn/corpus of the medial meniscus onto the inferior surface
medial collateral ligament complex intact
Lateral compartment
articular cartilage intact
lateral meniscus inconspicuous
lateral collateral ligament (LCL) torn and surrounded by fluid
popliteus muscle injury
fluid and soft tissue edema of the posterolateral corner structures and joint capsule
Patellofemoral compartment
chondral fissure of the superior medial patellar facet with subchondral changes
distal patellar tendinosis with ossification
quadriceps tendon unremarkable
Impression
posterolateral corner injury with disruption of the lateral collateral ligament (LCL)
incomplete longitudinal tear of the posterior horn and body of the medial meniscus
enchondroma of the lateral femoral metaphysis
patellar tendinosis