Knee arthroscopy
This factsheet is for people who are having a knee arthroscopy.
Arthroscopy is a "keyhole" operation that is used to look inside and treat joints, especially the knee joint. It is performed through small incisions in the skin, using a narrow telescope (arthroscope) attached to a video camera. Compared with open surgery, which involves a larger incision, arthroscopy is less painful, carries less risk of infection, and enables people to recover more quickly.
Why arthroscopy?
Arthroscopy is used both to investigate what is causing knee pain, and to treat a variety of knee conditions. Problems such as arthritis and inflammation can be diagnosed with arthroscopy, and it can be used to repair damaged tissue and cartilage. It is also used to take small tissue samples (biopsies), which can help with diagnosing things like infections. Knee arthroscopy is usually done as a day case.
Choosing an arthroscopy
Not everyone who has a knee problem needs to have an arthroscopy. In many cases, knee disorders can be diagnosed using non-surgical methods like MRI (magnetic resonance imaging), and some problems can be treated using physiotherapy. Your doctor can explain the benefits and risks of the procedure to you.
The operation
Arthroscopy is usually carried out under general anaesthesia, which means that you'll be asleep during the procedure. Sometimes, regional or local anaesthesia is used so that you can be awake while the operation is carried out.
Your surgeon and anaesthetist will advise you on the most suitable type of anaesthesia for you. For more information, see the BUPA health factsheets Epidurals for surgery and pain relief, Local anaesthesia and sedation and General anaesthesia.
Typically, you are required not to eat or drink for about six hours before a general anaesthetic.
Once the anaesthetic has taken effect, your surgeon will make two small cuts (about 5mm long) in the skin around the knee joint. The first cut is used to pump sterile fluid into the joint to help produce a clearer picture. The second cut is used to insert the arthroscope.
Your surgeon will examine the joint by looking at images sent by the arthroscope to a video screen. If necessary, other instruments can be inserted - sometimes through a third cut - to repair any damage or remove material that interferes with movement or causes pain in the knee.
Afterwards, the fluid is drained out and the cuts are closed with stitches or adhesive strips. Then a dressing and a bandage is wrapped around the knee. An arthroscopy can take from 30 minutes to over an hour, depending on how much work your surgeon needs to do inside the joint.
Illustration showing knee arthroscopy
After your operation
After coming round from the anaesthetic you'll need to rest for a while. Your knee may feel stiff and sore. Sometimes you will be given crutches to help you walk, but these aren't always needed.
If the operation was planned as a day case, you will usually be able to go home after you have recovered from the anaesthetic.
General anaesthesia can temporarily affect co-ordination and reasoning skills, so you should not drive, drink alcohol, operate machinery or sign legal documents until your doctor tells you that it is safe. This will be at least 24 hours after the operation. If you are in any doubt about driving, please contact your motor insurer so that you are aware of their recommendations, and always follow your doctor's advice.
Before you go home, a nurse should give you advice about caring for the healing wounds. A physiotherapist should also visit you to help get your joint moving and discuss exercising at home.
After you return home
At home, you might need to continue taking painkillers as advised by the nursing or medical staff, as the joint is likely to still be quite sore. If you are having this operation you should be prepared to take it easy for at least a few days, and avoid any strenuous exercise, lifting or carrying.
You will have a dressing and elasticated bandage over the knee joint. These apply pressure to assist with healing. The joint area needs to be kept clean and dry for about a week. You should use waterproof plasters over your healing wounds when you take a shower and avoid soaking your knee in the bath until the cuts are fully healed.
You should continue with the exercises recommended by your physiotherapist, as they will help to improve your knee movement and strength.
Your knee joint is likely to feel sore and swollen for at least a week. This can last longer if you have arthritis. Try to keep your leg raised up on a chair or footstool when you are resting. This will help to reduce swelling.
You should follow your surgeon's advice about returning to work and resuming your usual physical activities and sports. Don't drive until you feel you could do an emergency stop without discomfort.
Side-effects and complications
Arthroscopy is a commonly performed and generally safe surgical procedure. For most people, the benefits in terms of improved symptoms, or from having a clear diagnosis of a joint problem, are greater than the disadvantages. However, all surgery carries an element of risk. Below are some possible side-effects and complications of knee arthroscopy.
Side-effects
Side-effects are the unwanted but usually mild and temporary effects of a successful procedure. Examples of side-effects include feeling sick as a result of the general anaesthetic, although there are medicines available to help avoid this. After a knee arthroscopy you will have small scars on your knee from the incisions.
Complications
Complications are unexpected problems that can occur during or after the operation. Most people are not affected, but the main possible complications of any surgery are excessive bleeding, infection or an unexpected reaction to the anaesthetic. Complications may require further treatment such as returning to theatre to stop bleeding, or antibiotics to deal with an infection.
Arthroscopy complications can include accidental damage to the inside of the joint or a loss of feeling in the skin over the knee. There is also a risk of developing a blood clot in the veins of one of your legs - known as deep vein thrombosis (DVT). To help prevent this, you may be given a compression stocking to wear on the unoperated leg during the operation. You might also have an injection of anti-coagulant (blood thinning medication).
The chance of having a problem depends on the exact type of operation and other factors, like your general health. Ask your surgeon to explain how these risks apply to yo