Knee Instability
True knee instability occurs when the joint translates out of its ligamentous and muscular boundaries and the articular surface partially or totally disengages.
Patients state the knee gives way and feel exactly what happens as the knee subluxes or dislocates.
There is another type of giving way which occurs in knees which are ligamentously stable.
Knee pain from a torn meniscus for example an inhibit the quadriceps which causes the knee to bend and give way.
Anterior cruciate ligament injuries are the most common instability seen in the knee.
The history of injury usually involves a twisting injury as in a side stepping, cutting, jumping or landing force which is associated with a snap, pop or crack and collapse of the knee.