T HESE days it can be much quicker and easier to recover from a torn cartilage, or meniscus, than it was decades ago.

Each knee has two menisci, made of tough fibrocartilage, that lie on the surface of the shin bone or tibia. They are semi-circular and act as shock absorbers.

Injury usually occurs as a result of twisting at the knee when the joint is bearing weight. As a result the cartilage gets jammed between the shin bone and thigh bone or femur.

If the force is sufficient, a tear will occur. Unfortunately, damage to ligaments can often occur at the same time.

Main symptoms of a cartilage tear are pain and swelling, especially on running or weight bearing.

Sometimes the torn piece gets trapped, causing the knee to click on movement or lock in one position.

If the tear is small, the pain and swelling may settle but, for professional athletes, surgery is usually required before normal activity can be resumed.

In the past, this op involved opening the joint and removing the whole cartilage.This was a much more invasive procedure with a much longer rehabilitation time.

Loss of the whole cartilage inevitably resulted in premature arthritis of the joint and potentially knee joint replacement at a premature age.

Nowadays the op uses keyhole surgery that involves a small camera being inserted into the knee joint via an arthroscope. This allows the surgeon to trim the tear while preserving as much of the original cartilage as possible. It may even be possible to repair the cartilage to preserve it and reduce the risk of arthritis in the knee joint at a later age.

While cartilage damage is usually the result of injury, maintaining good strength in the hamstring and thigh muscles (quadriceps) may help to prevent or limit damage and will also assist in a speedy recovery.

The rehabilitation programme after surgery usually lasts between four to six weeks. This will vary due to the size, extent and location of the tear and it will be significantly longer if the cartilage is repaired rather than the tear trimmed.

At first the ability to put weight on the knee will be limited, so work in a pool is ideal. This helps to restore the range of movement in the knee while maintaining cardiovascular fitness.

Quadriceps and hamstring exercises should also be started as soon as possible as well as activities to improve balance and the knee joint's range of movement.

As rehabilitation progresses, cycling activity can be added followed by further weight-bearing exercises before you start gentle jogging, which should be limited initially and progressive.

Finally, activity specific to the sport can be added, such as twisting and turning in football before any work with the ball is begun in earnest.

The National Stadium Sports Health and Injury Clinic can be contacted on 0141 616 6161 or www.sportsmedicinecentre.org