The menisci are rubbery cushions that lie in the knee between the major bones of your knee, acting like shock absorbers. If you tear a meniscus, your knee will swell and become painful. You may feel that the initial pain has gone away, but an aching pain will return which will be particularly noticeable if you run, twist or flex the knee. Depending on which meniscus you tear, the pain could be on the inner or the outer knee. The pain may be worse at night.
Your knee may also click or ‘lock’ - this means you cannot straighten you knee. If your knee is locked you will need urgent medical attention. Left untreated a torn meniscus could lead to damage to the articular cartilage in your knee.
A tear in the meniscus is a common injury. Quite often an injury to the medial collateral ligament (MCL) can be mistaken for a torn meniscus. Your doctor will examine your knee and may well use an MRI scan to ascertain what kind of injury you have.
A torn meniscus can occur at almost any age but may coexist with arthritis in people aged 40 or over and will lead to water on the knee.
To begin with your doctor will probably prescribe RICE: Rest, Ice, Compression and Elevation. They may also give you anti-inflammatories for the pain. If your knee is stable and not locking, this may be all the treatment you need.
If your knee is locking then the pain can be eased with an arthroscopy, which is minimally-invasive keyhole surgery. The surgeon is able to trim the torn meniscus, then you should recover fully within six to eight weeks. If your meniscus is repaired rather than trimmed you may need crutches for a few weeks.