The knee is a hinge joint made up of many structures including:

Ligaments – There are 2 main ligaments inside the knee which provide support. These are the anterior (acl) and posterior cruciate ligament (pcl).

Cartilage – the knee is coated in a smooth bearing surface (articular cartilage) to allow it to glide easily.

Meniscus – Consisting of the medial (inner) and lateral (outer) meniscus these structures help the knee bend and rotate, as well as acting as shock absorbers.

Usually this is caused by a twisting type injury. Sometimes it results from a more complex injury where other structures are damaged.

The mechanism of injury may suggest a tear. You may experience sharp pain on either side of the knee, feel clicking or catching and sometimes the knee can lock. Clinical examination may reproduce this, but in some cases a MRI scan is needed to confirm the diagnosis.

When your symptoms fail to settle with other measures (e.g. physiotherapy) then key-hole surgery (arthroscopy) is performed. At surgery the meniscus is examined and where a tear is found, it will be treated by either trimming the torn portion or by suture repair.

The meniscus has poor healing qualities and so therefore only tears close to the blood supply can be repaired.

Through the keyhole incisions made in your knee, very fine sutures are passed across the tear and a knot tied.

During the surgery there is a risk of the fine suture injuring a nerve or vessel around the knee. This is uncommon, but may require further surgery. There is a risk that the repair fails. This is dependent on the type and location of the tear. Results in the literature vary from 60 – 70% success rate. Please also see the section on risks of knee arthroscopy.