A 28-year-old footballer sustains a knee injury with a valgus force. On examination, the anterior drawer and Lachman tests are positive. McMurray's test is also positive for a medial meniscal tear. The combination of ACL tear with medial meniscus and MCL injury is termed:
- A Pellegrini-Stieda syndrome
- B Osgood-Schlatter disease
- C O'Donoghue's unhappy triad (terrible triad of the knee) ✓
- D Plica syndrome
Correct answer: C. O'Donoghue's unhappy triad (terrible triad of the knee)
Explanation
O'Donoghue's unhappy triad (terrible triad) describes the combination of ACL tear, medial collateral ligament tear, and medial meniscus tear resulting from a valgus-external rotation force — the classic tackle injury in football. More recent studies suggest that the lateral meniscus tears at least as commonly in ACL injuries, but the classic triad remains the O'Donoghue triad for examination purposes. Pellegrini-Stieda syndrome is calcification of the MCL following old MCL injury.
Reference: Maheshwari Essential Orthopaedics, 6th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.