UK surgeons performed more than 100,000 ⁽¹⁾ arthroscopies in 2007, most of which were performed on knee joints.

An arthroscopy, also known as keyhole surgery, is a medical procedure that allows a surgeon to examine the inside of a joint.

Seventeen out of every 20 arthroscopies ⁽²⁾ involve the knee joint, while two in 20 ⁽³⁾ involve the shoulder. The remainder are done on the ankle, elbow, wrist, hip and even the finger joints ⁽³⁾.

The arthroscope itself is a pencil-thin telescope inserted into the joint through a small incision at the front side of the knee. It has a light and a tiny video camera at the end and pictures of the inside of the joint are sent to a TV or computer monitor, so the surgeon can see what the problem is.

An arthroscopy is used to repair damage and remove pieces of bone, cartilage or ligaments that have broken off and are irritating the joint. Small surgical instruments are also inserted into the knee joint through another small incision.

The procedure is also used to take biopsies, if you have a suspected infection in your knee.

Why would I need an arthroscopy?

You may need an arthroscopy if you have knee injury caused by sport or arthritis, both of which can cause pain, inflammation, swelling and weakness.

Arthroscopies are commonly used to treat torn cartilage (meniscal injury to the two areas of cartilage covering the inner and outer parts of the lower part of the joint).

Arthroscopy is low-risk surgery, with complications in only one to two per cent ⁽⁴⁾ of procedures. Ask your surgeon what his or her success rate is.

Other commonly treated injuries include torn cruciate ligaments, which are found in the middle of the knee joint and connect the calf and thigh bones.

Arthroscopy may help reduce pain in early stage osteoarthritis by repairing rough and damaged joint surfaces and cartilage. It is also used to remove the synovial membrane that surrounds the joint, as it can become thickened and inflamed in people with arthritis. Arthroscopy cannot cure arthritis.

Are there any alternatives?

An MRI scan (magnetic resonance imaging) or X-ray are non-invasive diagnostic tools, but if the resolution is unclear, an arthroscopy may be necessary anyway.

An arthroscopy may also be recommended if physiotherapy, painkillers and knee supports have failed to relieve pain or improve mobility.

Before the introduction of arthroscopy, the only option was to have the whole joint opened up, which carried a much greater risk of infection. Thanks to the development of this procedure, most surgery now has a far lower risk of complications, with reduced pain, shorter hospital stays and quicker recovery times.

How is an arthroscopy performed?

An arthroscopy takes between half an hour and an hour, depending on how much damage there is. You will have either a local or general anaesthetic.

For the local, a spinal anaesthetic (epidural) will numb your lower body and you will be awake during the procedure. If you have a general, you will be asleep the whole time.

X-rays and/or an MRI scan may be performed before surgery to assess how much damage exists in your knee.

The skin on and around your knee is first cleaned with an antibacterial liquid.

Two or three millimetre-wide incisions are made either side of the front of the knee and the arthroscope is inserted through one incision and an examining probe or surgical instruments inserted through the other.

The joint may also be flooded with sterile fluid to make it easier to see what is going on inside. If you have osteoarthritis, this will also flush out any debris (arthroscopic knee wash-out and debridement), which temporarily helps relieve arthritic symptoms.

By watching the arthroscope images, the surgeon can diagnose any damage and move instruments around the joint to make repairs.

The arthroscope and any other instruments are then removed, fluid drained away and incisions stitched or taped closed and covered with a sterile dressing.

How long is the hospital stay?

Most people can go home the same day. If you are elderly, or have other medical conditions, you may have to stay overnight.

Stiffness and soreness in your knee is likely afterwards, so you will be given painkillers to take at home. You may also need to use crutches to help you walk for a day or two, but they are not usually necessary.

If you had a general anaesthetic, you must not drive, drink alcohol or operate machinery for at least 24 hours, since it can affect co-ordination.

Before you leave hospital, your surgeon should also arrange your outpatient appointment to discuss the results of the arthroscopy in the near future.

What's the recovery time?

Most people return to work a week or so afterwards, depending on the type of job they do (if your work is physically exerting, you may need more time).

You should rest for the first few days by keeping your leg raised to help reduce swelling. Avoid any lifting, carrying or other strenuous activity.

Walking and other light exercise is necessary, however. Your surgeon will recommend specific exercises. You can drive again when you can perform an emergency stop without any difficulty.

Do not play sports or do any strenuous activities for three to six weeks. Your surgeon will tell you what you can and cannot do before discharging you from hospital.

Are there any risks I should know about?

Arthroscopy is generally safe, but all surgeries carry some risk.

The general anaesthetic can make some people feel nauseous afterwards. You will also have scars where the incisions were made, but these are very small.

Complication rates from arthroscopy are lower ⁽⁵⁾ than conventional surgery. Infection, damage in and around the joint and bleeding inside the joint are the commonest.

If you experience increasing pain, swelling or tenderness in the joint after going home, if you develop a fever or numbness and tingling around the joint, or if you see fluid, pus or blood coming from the incision wounds, see your doctor immediately.

Infolink:

• British Orthopaedic Association