Related Experiment Video
Updated: Jul 27, 2025

Tissue Collection and RNA Extraction from the Human Osteoarthritic Knee Joint
Published on: July 22, 2021
Unhappy triad of the knee: What are the current concepts and opinions?
Amir Human Hoveidaei1, Reza Sattarpour2, Haleh Dadgostar3
1Sports Medicine Research Center, Tehran University of Medical Sciences, Tehran 14395-578, Iran.
Abstract:
The association between injuries to the anterior cruciate ligament, medial collateral ligament, and medial meniscus (MM) has been known to orthopedic surgeons since 1936; O'Donoghue first used the term "unhappy triad" of the knee to describe this condition in 1950. Later studies revealed that involvement of the lateral meniscus is more common than MM in these cases, leading to a change in the definition. Recent studies have revealed that this triad may be primarily linked to knee anterolateral complex injuries. Although there is not a definite management protocol for this triad, we try to mention the most recent concepts about it in addition to expert opinions.
Related Concept Videos
Knee Joint
A total of seven ligaments support the knee joint. The patellar ligament, which is also attached to the quadriceps femoris...
Bones of the Lower Limb: Femur and Patella
Ankle Joint

