Presentation
Sustained a fall.
Patient Data
Age: 25 years
Gender: Male
From the case:
Osteochondral knee fracture due to pivot-shift injury
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Irregularity of the articular surface of the lateral femoral condyle but no unequivocal fracture line or signs of joint effusion. Small extra-articular calcific structure in the anterosuperior soft tissues.
From the case:
Osteochondral knee fracture due to pivot-shift injury
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CT confirms the osteochondral injury, also showing predominantly medial stranding of the subcutaneous fat planes.
From the case:
Osteochondral knee fracture due to pivot-shift injury
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MRI knee reveals the full extent of the injuries:
- the anterior cruciate ligament is completely torn
- the medial collateral ligament is also ruptured, and surrounded by hemorrhage
- bone edema in the dorsal aspect of the lateral tibia condyle indicating a pivot-shift mechanism
- osteochondral fracture of the lateral femoral condyle
- bucket handle tear of the posterior horn and root of the lateral meniscus with medial displacement
- significant knee joint effusion with small loose bodies
- diffuse surrounding soft tissue edema and hemorrhage
- mild thickening of the popliteus and adductor magnus tendons indicating partial injury
Case Discussion
This case shows extensive injuries stemming from pivot-shift trauma, and also demonstrates that plain film or CT substantially underestimates the extent of damage. The bucket handle-like lateral meniscal rupture is a somewhat unusual, relatively rarely seen feature.
Also contributed by dr. Andras Toth