O’Donoghue unhappy triad

O’Donoghue unhappy triad or terrible triad often occurs in contact and non-contact sports, such as basketball, football, or rugby, when there is a lateral force applied to the knee while the foot is fixated on the ground. 

This produces an abduction-external rotation mechanism of injury (“pivot shift” in non-contact sports).

Pathology

The O’Donoghue unhappy triad comprises three types of soft tissue injury that frequently tend to occur simultaneously in knee injuries. O’Donoghue described the injuries as:

Anterior cruciate ligament tear

Medial (Tibial) collateral ligament injury

Medial meniscal tear (lateral compartment bone bruise)