The knee joint contains a medial (inner) meniscal cartilage and a lateral (outer) meniscus. The menisci absorb load which is placed onto the knee and protect the smooth articular cartilage on the joint surfaces. They also help to stabilise and lubricate the knee joint.
The meniscal cartilages may be torn due to a high energy sports related injury but tears can also occur with much lower forces such a trivial twisting mechanism.
Symptoms commonly include pain, swelling and mechanical symptoms in the knee. This may be described as locking, catching or giving way and is often made worse when the knee joint is in a flexed position for example when crouching or kneeling down. Activities which involve twisting and turning can be particularly uncomfortable.
Diagnosis of meniscal tears is made on history, clinical examination and MRI scan. Unfortunately, these injuries are not shown on a plain x-ray and are consequently missed. A small number of cartilage tears can heal themselves but surgery is often required for recurrent symptoms.