O'Donoghue's unhappy triad

Case contributed by Mohammad A. ElBeialy
Diagnosis certain

Presentation

Knee pain, swelling and giving away for 3 months since trauma.

Patient Data

Age: 30 years
Gender: Male
mri

Bucket-handle tear of the posterior horn of medial meniscus with double PCL sign and increased intra-meniscal signal seen disrupting both articular surfaces and menisco-capsular attachment. Full-thickness tear of the ACL with indistinct outline and increased signal intensity. The medial collateral ligament shows mild thickening with increased signal intensity within and around. Moderate joint effusion. The posterior lateral tibial condyle shows patchy area of marrow edema signal demonstrating low T1 and bright PDFS and STIR signal. The popliteus muscle shows edema signal with high T2, PDFS and STIR signal.

Case Discussion

O'Donoghue's unhappy triad results from valgus stress with rotation of the knee. It comprises ACL tear and MCL injury (tear or sprain) with a medial meniscal tear.

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