Knee arthroscopy

Published by Bupa's Health Information Team, December 2010.

This factsheet is for people who are planning to have a knee arthroscopy, or who would like information about it.

Knee arthroscopy is a type of keyhole surgery, used to look inside and treat the knee joint.

You will meet the surgeon carrying out your procedure to discuss your care. It may differ from what is described here as it will be designed to meet your individual needs.

How knee arthroscopy is carried out

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About knee arthroscopy

You may have knee arthroscopy to investigate problems such as inflammation or injury, or to repair damaged tissue and cartilage. It’s also used to take small tissue samples (biopsies), which can help to diagnose problems such as infection.

Knee arthroscopy is performed through small cuts in your skin, using a special telescope (arthroscope) attached to a video camera. Compared with open surgery, arthroscopy has a faster recovery time.

What are the alternatives?

Not everyone who has a knee problem needs to have an arthroscopy. Your doctor may diagnose your knee problem using physical examination, an X-ray or an MRI scan. An MRI scan uses magnets and radiowaves to produce images of the inside of your body. Some problems can be treated using physiotherapy and medicines.

Preparing for a knee arthroscopy

Your surgeon will explain how to prepare for your operation. For example if you smoke you will be asked to stop, as smoking increases your risk of getting a chest and wound infection, which can slow your recovery.

The operation is usually done as a day case under general anaesthesia. This means you will be asleep during the procedure. Alternatively you may have the surgery under local or regional anaesthesia. This completely blocks the pain from the knee area and you will stay awake during the operation. Your surgeon may offer you a sedative with a local or regional anaesthetic, which relieves anxiety and helps you to relax during the operation.

If you're having general anaesthesia, you will be asked to follow fasting instructions. This means not eating or drinking, typically for about six hours beforehand. However, it’s important to follow your anaesthetist’s advice.

At the hospital your nurse may check your heart rate and blood pressure, and test your urine.

Your surgeon will discuss with you what will happen before, during and after your procedure, and any pain you might have. This is your opportunity to understand what will happen, and you can help yourself by preparing questions to ask about the risks, benefits and any alternatives to the procedure. This will help you to be informed, so you can give your consent for the procedure to go ahead, which you may be asked to do by signing a consent form.

You may be asked to wear a compression stocking on the unaffected leg to help prevent blood clots forming in the veins in your legs. You may need to have an injection of an anticlotting medicine called heparin as well as, or instead of, wearing compression stockings.

What happens during a knee arthroscopy

An arthroscopy can take from 30 minutes to over an hour, depending on how much work your surgeon needs to do inside your knee joint. Once the anaesthetic has taken effect, your surgeon will make small cuts in the skin around your knee joint. He or she will pump sterile fluid into your joint to help produce a clearer picture and then insert the arthroscope.

Your surgeon will examine your knee joint by looking at images sent by the arthroscope to a monitor. If necessary, he or she can insert instruments to repair damage or remove material that interferes with movement or causes pain in your knee.

Afterwards, your surgeon will drain the fluid out and close the cuts with stitches or adhesive strips. Then he or she will wrap a dressing and a bandage around your knee.

What to expect afterwards

You will need to rest until the effects of the anaesthetic have passed. It may take several hours before the feeling comes back into your knee. Take special care not to bump or knock the area.

You may need pain relief to help with any discomfort as the anaesthetic wears off.

You will usually be able to go home when you feel ready.

You will need to arrange for someone to drive you home. You should try to have a friend or relative stay with you for the first 24 hours.

Your nurse will give you some advice about caring for your healing wounds before you go home. You may be given a date for a follow-up appointment. A physiotherapist should also visit you to help get your joint moving and discuss exercising at home.

The length of time your dissolvable stitches will take to disappear depends on what type you have. However, for this procedure they should usually disappear in about six weeks. Non-dissolvable stitches are removed 10 to 14 days after surgery.

Recovering from knee arthroscopy

If you need pain relief, you can take over-the-counter painkillers such as paracetamol or ibuprofen. Always read the patient information that comes with your medicine and if you have any questions, ask your pharmacist for advice.

General anaesthesia temporarily affects your co-ordination and reasoning skills, so you must not drive, drink alcohol, operate machinery or sign legal documents for 24 hours afterwards. If you're in any doubt about driving, contact your motor insurer so that you're aware of their recommendations, and always follow your surgeon’s advice.

Some people may have to wear special pads, attached to an intermittent compression pump, on their lower legs. The pump inflates the pads and encourages healthy blood flow in your legs and helps to prevent DVT.

You may also be wearing compression stockings on your unaffected leg to help maintain circulation.

You will have a dressing and an elasticated bandage over your knee joint. These apply pressure to assist with healing. You need to keep your knee clean and dry for about one to two weeks. You should use waterproof plasters over your healing wounds when you take a shower and don't soak your knee in the bath until the cuts are fully healed.

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 on a chair or footstool when you're resting. You should apply a cold compress such as ice or a bag of frozen peas, wrapped in a towel, to help reduce swelling and bruising. Don’t apply ice directly to your skin as it can damage your skin.

Follow your surgeon's advice about driving. You shouldn't drive until you're confident that you could perform an emergency stop without discomfort. This is usually about one to three weeks after your operation.

Your recovery time will depend on what, if any, treatment your surgeon performs on your knee joint. You should be able to resume your usual activities after six to eight weeks depending on the severity of your knee problems and your level of fitness.

What are the risks?

Knee arthroscopy is commonly performed and generally safe. However, in order to make an informed decision and give your consent, you need to be aware of the possible side-effects and the risk of complications of this procedure.

Side-effects

These are the unwanted, but mostly mild and temporary effects of a successful treatment, for example feeling sick as a result of the general anaesthetic.

After a knee arthroscopy you will have small scars on your knee from the cuts.

Complications

This is when problems occur during or after the operation. Most people aren't affected. The possible complications of any operation include an unexpected reaction to the anaesthetic, a wound infection, excessive bleeding or developing a blood clot, usually in a vein in the leg (DVT).

Arthroscopy complications can include:

• accidental damage to the inside of your joint
  
• infection
  
• loss of feeling in the skin over your knee
  
• bleeding into your joint
  
• the surgery may not be successful or it may have to be repeated

The exact risks are specific to you and differ for every person, so we haven't included statistics here. Ask your surgeon to explain how these risks apply to you.

For answers to frequently asked questions on this topic, see FAQs.

For sources and links to further information, see Resources.