Unhappy triad
From Wikipedia, the free encyclopedia
An unhappy triad (or terrible triad, or O'Donoghue's triad[1]) is an injury to the knee. It commonly occurs in contact sports (such as American football). The mechanism for this injury occurs when a lateral (outside) force to the knee is received while the foot is fixed on the ground.
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[edit] Structures in triad
This scenario causes an injury to three knee structures:
- the anterior cruciate ligament
- the medial collateral ligament (or "tibial collateral ligament")
- the medial meniscus
The inclusion of the medial meniscus in the triad has been challenged.[2]
The reason that the medial collateral ligament and medial meniscus are injured together is because they are attached to one another in the knee joint.
[edit] Terminology
The term "unhappy triad" was coined by O'Donoghue in 1950.[2][3][4] However, since then the terms "unhappy triad" and "terrible triad" have also been used to describe several other combinations of joint injuries, including those of the elbow[5] and shoulder.[6]
The term "terrible triad" is also sometimes used in the popular press to describe conditions relating to pain, or even to refer to the MacDonald triad.
[edit] See also
[edit] Additional images
 Left knee-joint from behind, showing interior ligaments. |
 Capsule of right knee-joint (distended). Posterior aspect. |
[edit] References
- ^ Shelbourne K, Nitz P (1991). "The O'Donoghue triad revisited. Combined knee injuries involving anterior cruciate and medial collateral ligament tears". Am J Sports Med 19 (5): 474-7. PMID 1962712.
- ^ a b Barber F (1992). "What is the terrible triad?". Arthroscopy 8 (1): 19-22. PMID 1550645.
- ^ O'Donoghue D (1950). "Surgical treatment of fresh injuries to the major ligaments of the knee". J Bone Joint Surg Am 32 (A:4): 721-38. PMID 14784482.
- ^ O'Donoghue D. "The unhappy triad: Etiology, diagnosis and treatment". Am J Orthop 6: 242-7 PASSIM. PMID 14237439.
- ^ Pugh D, McKee M (2002). "The "terrible triad" of the elbow". Tech Hand Up Extrem Surg 6 (1): 21-9. PMID 16520629.
- ^ Simonich S, Wright T. "Terrible triad of the shoulder". J Shoulder Elbow Surg 12 (6): 566-8. PMID 14671520.
