The meniscus is a C-shaped wedge of cartilage that sits in the knee between the femur (thigh bone) and tibia (shin bone), and acts to provide stability and distribute load evenly through the knee. There are two menisci, the medial meniscus is on the inner side and the lateral meniscus on the outer side of the knee.
In younger patients, menisci usually only tear following an injury to the knee. Typically, this is a twisting injury, often with the foot planted while the knee is bent.
As we age, the menisci begin to degenerate and are more likely to tear with minor trauma. Sometimes, tears can occur with innocuous activities such as kneeling or squatting or without recollection of any specific event. Degenerate tears are common in the presence of knee osteoarthritis.
With an acute injury, you may experience a sudden sharp pain sometimes associated with a ‘pop’ felt or heard inside the knee. This is often followed by moderate swelling which usually appears a number of hours after the injury.
Other symptoms include intermittent pain, swelling, clicking or catching sensations, giving way and locking.
The history and examination findings are usually supported with a MRI scan. An x-ray may also be requested to assess degenerative changes within the joint.