Final answer:
A clicking sound in the knee when flexed, with rotation and pressure applied, suggests a meniscal tear, likely due to a traumatic 'terrible triad' injury sequence including tibial collateral ligament and ACL damage.
Step-by-step explanation:
When a clicking sound is heard upon flexing the knee, rotating the tibia, and applying pressure to the sides of the knee, it may be indicative of a meniscal tear. This type of injury is commonly associated with a trauma that exerts force on the extended knee. In particular, a sudden blow to the lateral knee, known as the "terrible triad" injury sequence, often results in the tearing of the tibial collateral ligament, damage to the medial meniscus, and rupture of the anterior cruciate ligament (ACL). The medial meniscus, more prone to injury, is attached to the tibial collateral ligament, making it more susceptible to damage when the knee is subject to such forces. ACL injuries can result from hyperextension, twisting, or a direct force to the knee while the foot is planted. For such knee injuries, arthroscopic surgery is a common treatment that can lead to a rapid recovery.