Knee arthroscopy (keyhole surgery)

A knee arthroscopy is a type of surgery used to examine the inside of your knee joint. It is used to diagnose a range of knee problems, and certain conditions can also be treated during the same operation. You might also hear it referred to as arthroscopic knee surgery.

An arthroscopy is a keyhole operation, which means it's done using a small incision. Your surgeon, usually an orthopaedic consultant, will use specially designed surgical tools to access your knee joint through a few small cuts. One of these tools will be a camera (known as an arhthroscope), which is what allows them to see inside your knee without having to 'open it up'.

An arthroscopy should allow your consultant to diagnose the cause of your knee pain symptoms. If possible, they will also treat the problem during the same procedure. For example, they may be able to repair a torn ligament, or clear cartilage that is causing you problems. 

Arthroscopic knee surgery is a common procedure with a good success rate, which has become more popular as technologies have advanced. In the years from 2000 to 2010, there was a 69% increase in the number of knee arthroscopies performed in the UK.¹

This page tells you everything you need to know about a knee arthroscopy, from the symptoms and conditions that it can be used to treat, to what to expect from your recovery after surgery.

Knee arthroscopy is usually considered when alternative, non-surgical treatments have not successfully alleviated your knee pain. Non-invasive treatments might include pain relief medication, steroid injections or physiotherapy. If these methods have been tried and have not been able to to improve your quality of life, and you're still living with intense pain, stiffness or swelling, it might be time to have knee surgery.

Some of the common conditions that are treated with a knee arthroscopy include:

A torn meniscus

Your menisci are pieces of a cartilage found on the outside (lateral) and the inside (medial) of your knee. They act as a cushion between your femur (thigh bone) and tibia (shinbone). As well as supporting your knee joint, your meniscus is responsible for absorbing shock, bearing weight, and stabilising and lubricating your joint. Your meniscus can become torn or damaged during an activity or injury that applies pressure to your knee or causes your joint to twist. You might hear this referred to as a meniscal tear.

If left untreated, a torn meniscus can irritate your joint’s surface and damage your articular cartilage, which can lead to arthritis. Your articular cartilage covers the ends of your tibia (shinbone), femur (thighbone) and patella (kneecap) — these bones all meet to form your knee joint. An arthroscopy can be performed to repair or remove a torn meniscus.

What is a knee arthroscopy and meniscectomy procedure?

A meniscectomy is the procedure to remove your torn meniscus through a knee arthroscopy (keyhole surgery). A partial meniscectomy refers to the removal of only a part of your torn meniscus through knee arthroscopy.

A torn anterior cruciate ligament

A torn or ruptured anterior cruciate ligament (ACL) is a common injury sustained while playing sports such as football, skiing and netball. ACL reconstruction surgery is often carried out during an arthroscopy. Your torn ligament will be removed and replaced with tissue taken from another part of your body, or from a donor.

Inflamed synovial tissue

Your synovium is a membrane that lines and lubricates your joints. Osteoarthritis (a wear and tear form of arthritis) can trigger inflammation in your synovial tissue. Inflammatory arthritis such as rheumatoid arthritis can also cause your synovium to become inflamed, as this form of arthritis causes your immune system to attack the healthy tissue around your joints. This inflammation can damage other areas of your joint, for example your bones, cartilage, tendons and ligaments. But an arthroscopy can be used to remove inflamed synovial tissue.

Osteoarthritis

Osteoarthritis is the most common form of arthritis in the UK. It occurs when the cartilage in your joint begins to break down. As your cartilage deteriorates, the bones that form your knee joint can rub together, causing pain and restricted movement. Sometimes, broken cartilage or bone from osteoarthritis or an injury can float in your joint, which can cause your knee to lock and prevent you from being able to completely straighten your knee. An arthroscopy might be recommended to remove any loose cartilage or bone in your joint.

Moreover, osteoarthritis can impact your nearby bones, causing them to become enlarged in certain areas. These enlargements are referred to as bone spurs and can be treated through arthroscopic surgery.

Arthroscopic knee surgery is performed by an orthopaedic surgeon to diagnose and treat a range of problems in your knee, from knee pain to reduced mobility, to persistent swelling in your knee. 

Although an arthroscopy is a keyhole operation, and therefore a minimally invasive procedure, it is always a significant undertaking to have surgery. It will only be recommended if your symptoms are severe and have not responded to less-invasive treatments. 

Symptoms that can lead to a recommendation of knee arthroscopy include:

Your knee locking

Loose cartilage or bone in your joint, for example from osteoarthritis or an injury to your meniscus, can cause locking and make it difficult to straighten your knee.

Your knee giving way

This can be a sign of instability in your knee, which can occur following an injury.

Severe knee pain

Pain can be experienced in different areas of your knee. Anterior knee pain (front of knee pain) is the most common type of knee pain. The NHS estimates that it will affect around a quarter of the UK population at some point in their lifetime. It can be caused by a variety of injuries and conditions, from bursitis to patellofemoral pain syndrome.

Pain on the outside of your knee is often caused by iliotibial band syndrome. This is an overuse injury where your iliotibial band (band of tissue in your thigh) rubs against the outside of your joint.

Swelling

If you have any immediate swelling (up to two hours after an injury or trauma), it might be a symptom of a fracture, a ruptured ligament, or a dislocated patella (kneecap). But swelling that happens gradually (after six to 24 hours) could be due to a torn meniscus. Septic arthritis (an infection of your joint) and inflammatory types of arthritis, such as rheumatoid arthritis, can also cause swelling.

A popping sound

If you hear a popping or snapping sound following an injury, this could indicate that you have torn a ligament in your knee.

When should I speak to a specialist about knee problems?

If you are experiencing any of the above symptoms, it is important that you seek appropriate treatment. Most people with knee pain find that, with the help of a specialist consultant, they are able to find a way to manage their knee problems. In many cases, knee pain is significantly reduced, or even eliminated.

According to our Joint Pain Matters 2020 report, which examines the impact of joint pain on the lives of more than 8,000 people in the UK, people with knee pain are more likely to seek professional help than those with any other type of joint pain (for example, elbow pain, hip pain or ankle pain). This could reflect the debilitating impact that knee pain can have on your quality of life: 99% of the people who took part said their quality of life has been affected by their knee pain symptoms.

Pain can impact your quality of your life by disrupting your sleep, interfering with your productivity at work and restricting your ability to participate in social and family activities. Moreover, coping with pain can take a toll on your mental health. 71% of people with knee pain said their mental health has been affected by their condition. Close to 80% of people with knee pain reported that joint pain had affected their family life, and around 50% of people with knee pain shared that joint pain had impacted their career, romantic relationships and ability to attend social events.

Although pain can be challenging, there are many effective treatment options available to reduce your pain and help you live an active, fulfilled life.

If you are advised to have arthroscopic knee surgery, your consultant will explain how to prepare for your procedure, what happens during your surgery and the benefits that are involved. Your consultant will also discuss your recovery and any rehabilitation that you might need following your surgery.

As with any surgical procedure, you will be encouraged to improve your fitness to support your overall health. The healthier and fitter you are before surgery, the better chances it will be a success.

In addition to improving your fitness, you could be required to make some changes to your lifestyle. These include:

Quitting smoking

Smoking significantly increases your risk of suffering complications during and following orthopaedic surgery. By avoiding smoking before your procedure, you can minimise your risk of complications from anaesthesia and of delayed wound healing. If you smoke, your consultant can offer you more information and support on how to quit smoking and when to stop smoking before your arthroscopy.

Weight loss

Being overweight can put you at risk of experiencing complications from anaesthetic, which is administered before starting a knee arthroscopy. If you are overweight, your orthopaedic surgeon will therefore advise losing weight before your procedure.

As well as minimising the risks posed by anaesthesia, weight loss can relieve pressure on your joint, which in turn can reduce knee pain.

Knee exercises

You will be given exercises to do before and after your surgery. These exercises will be explained to you by a physiotherapist at your chosen Circle Health Group hospital.

Your pre-operative assessment

Prior to your knee arthroscopy, you will have a pre-operative assessment. This will include a general health check where your consultant or a nurse will check your urine, weight and blood pressure. You could be asked to bring any medication that you are currently taking and a sample of your urine in a clean container to this assessment.

During your pre-operative assessment, your consultant or a nurse will also perform a blood test and an MRSA swab — this is a simple test that involves rubbing a cotton bud against your skin to check for the presence of MRSA (a type of bacteria). You could be advised to have an X-ray or an echocardiogram (ECG), which is a scan used to examine the condition of your heart.

If you are administered general anaesthetic before your knee arthroscopy, you will not be able to drive for at least 24 hours after your surgery. It is therefore recommended that you do not drive yourself to our hospital. Instead, you can request a family member or friend to drive you to our hospital.

The dos and don'ts ahead of your arthroscopy

Things to do

• Bring your medication to your surgery and pre-assessment
• Inform your consultant of any medication that you are taking
• Discuss any concerns that you have with your consultant

Things to avoid

• If you are wearing any contact lenses, these will need to be removed prior to your surgery
• Avoid wearing any nail varnish or jewellery, as you will be asked to remove these before your operation
• If you were given general anaesthetic, do not drive for at least 24 hours after your operation

On the day of your arthroscopic knee surgery, your orthopaedic surgeon will explain what will happen during your procedure, including the risks, benefits and what to expect after your surgery. Your healthcare team will also check your blood pressure and heart rate.

Once you are under anaesthetic, a pressure cuff will be placed around your upper thigh to restrict blood flow to your knee. This allows your orthopaedic surgeon to have a clearer view of the inside of your knee.

Afterwards, your surgeon will make three small incisions in the skin on the side of your knee to create portals (holes) in your knee joint. An arthroscope (a thin tube with a camera and a light) is passed through one of these portals in your knee. A saline solution is passed through the second portal. This solution allows the inside of your joint to be seen more clearly.

Specalised instruments are then passed into the third portal in your knee to perform your arthroscopic surgery. The type of arthroscopy you have will depend on your diagnosis and can involve removing or trimming any damaged tissue or cartilage.

What kind of anaesthetic is used during knee arthroscopy?

Although you will usually be given a general anaesthetic before a knee arthroscopy, you could be offered a spinal anaesthetic (an injection in your lower back to numb the bottom part of your body) as an alternative. During your arthroscopic surgery, a local anaesthetic might be injected into your knee to minimise pain following your operation.

How long does a knee arthroscopy take?

An arthroscopy can take between 30 minutes to two hours to perform. But this will depend on the type of procedure that you have. You will usually be able to return home the same day of your surgery, or the following day.

Are there different types of knee arthroscopy?

There are several types of arthroscopic knee surgery, including:

Arthroscopic lavage

Arthroscopic lavage, also called an arthroscopic washout, is when your knee joint is flushed with a fluid that is passed through one of the incisions in your knee. This removes any loose tissue or bone. This procedure is often performed alongside an arthroscopic debridement.

Arthroscopic debridement

During an arthroscopic debridement, your consultant surgeon will remove any damaged or loose cartilage or bone in your joint.

Arthroscopic partial meniscectomy

An arthroscopic partial meniscectomy (APM) is the most common knee procedure performed in the UK. It refers to the partial removal of a torn meniscus.

Meniscectomy

This refers to the complete surgical removal of a torn meniscus.

Immediately after surgery

After your arthroscopic knee surgery, your incisions will be closed with either dissolvable stitches, which can take between two to six weeks to dissolve, or non-dissolvable stitches that will need to be removed after about 10 to 12 days.

If your stitches need to be removed, your consultant will arrange a follow-up appointment to remove them. Small dressings will be placed over these stitches and your knee will be bandaged by your consultant. It is important that you keep these dressings dry and clean until your incisions have completely healed. Your surgeon will explain how to keep your wounds clean.

Following your surgery, you will be taken to a recovery room in our hospital. A nurse will monitor your blood pressure and temperature and offer you a drink or some food. Your orthopaedic surgeon will ask about the level of pain you are in and offer pain relief through injections or tablets, if needed. If a local anaesthetic was injected into your knee during your surgery, this can provide pain relief for around four to six hours following your operation.

It is normal to experience pain, swelling or discomfort after your arthroscopy. Your orthopaedic surgeon will give you pain relief medication to take home to support your recovery.

Before you leave our hospital, a physiotherapist will offer you a programme of specific exercises to perform at home. They will guide you through these exercises to ensure that you are performing them correctly and safely. Doing these physiotherapy exercises after an arthroscopy will help strengthen your knee, improve your movement and support your return to your daily activities. Your exercise plan will be tailored to your post-surgery needs and requirements. It could include knee flexion (bending) or knee extension (straightening) exercises.

One to two days after surgery

You will be able to eat and drink shortly following your arthroscopic surgery. You should also be able to walk after your surgery, but you might need crutches to support you. Your consultant will advise that you avoid long walks or standing for prolonged periods. If you need to climb any stairs, it is recommended that you go up on the step with your good knee first and then down with your treated knee.

24 hours after surgery, the effects of your anaesthetic will have worn off and it'll be safe for you to shower or bathe. However, you will need to keep the dressings over your wounds dry and might require some assistance to help you shower or bathe. If your dressings do become wet, you will need to place new dressings over your wounds. You should avoid touching your wounds to prevent an infection. Before you leave our hospital, your healthcare team and your consultant will explain how to look after your wounds, including what to do if your dressings become wet.

One to two weeks after surgery

Many people feel back to normal as early as one or two weeks after surgery. Even if you are feeling better after only a week or two, it's a good idea to take things easy nonetheless, to avoid pushing yourself too far.

Returning to work after a knee arthroscopy

Your return to work after an arthroscopy will depend on your profession and the requirements of your role. If you have an office job, where you spend most of your day sitting down, you should be able to return to work a week after your arthroscopic knee surgery. But if your role is more physically demanding, you might need to avoid working for up to two weeks.

Six to 12 weeks after surgery

Many people feel they have recovered six weeks after a knee arthroscopy. Yet others won't feel back to normal for 12 weeks. The complete recovery time for an arthroscopy of the knee will vary depending on your condition and the arthroscopic procedure(s) used during your surgery.

You might need to have a follow up appointment with your orthopaedic surgeon after two and six weeks. At these appointments, your orthopaedic surgeon will remove any stitches (if non-dissolvable stitches were used to close your incisions) and examine how your wounds are healing. They will look at how your knee is moving and decide whether further physiotherapy sessions are needed. They will also work with your physiotherapist at our hospital to support your recovery.

Your return to sport after a knee arthroscopy

You should avoid playing sport until the swelling in your joint has gone and your knee is strong enough for you to comfortably exercise with it. Your orthopaedic surgeon and physiotherapist will be able to advise on when it is best for you to return to playing sport.

How soon can you drive after knee arthroscopy?

If you have been given general anaesthetic, you will not be able to drive or use any machinery for at least 24 hours after your surgery. After an arthroscopic procedure, you should refrain from driving until the pain or swelling in your knee has resolved and you have regained complete movement. Your consultant will be able to give you a better idea of how soon this will be.

As with any surgery, there are risks that can occur following your arthroscopy. The risks and complications that are associated with arthroscopic knee surgery include

Infection

If you do suffer an infection, this can be treated with antibiotics.

A blood clot

As you will be able to move around after your surgery, there is a low risk of developing a blood clot.

Scarring

You could have small scars where your incisions were made, but these should become less obvious with time.

Swelling

Although it is common to experience swelling in your knee after an arthroscopy, this swelling should only last for up to three weeks.

Haemarthrosis (bleeding)

Haemarthrosis refers to bleeding in your joint after an arthroscopy. It can cause discomfort and pain but your consultant can treat this by aspirating the blood in your knee joint (using a small needle and a syringe to remove the blood in your joint).

We answer your frequently asked questions about having a knee arthroscopy.

What does a knee arthroscopy (keyhole surgery) look for?

An arthroscopy allows an orthopaedic surgeon to examine the inside of your knee. It can help diagnose and treat the cause of symptoms such as knee pain and stiffness. It looks for problems such as loose cartilage, torn ligaments, and other damage to your joint.

How long does it take to perform a knee arthroscopy?

In most cases, a knee arthroscopy can take less than an hour to perform. However, this will depend on your diagnosis and the arthroscopic procedures that are involved in your surgery.

What happens after my surgery?

After your arthroscopic surgery, a dressing will be placed over your knee to minimise swelling. Your healthcare team will check if you can lift your treated leg off the hospital bed with a straight knee. If you can do this following your operation, you will be encouraged to get up from your hospital bed and walk around. But if you need support with walking, you might be given crutches.

How long will I need to stay in hospital after a knee arthroscopy?

You will usually be able to go home the same day. Sometimes you will need to stay overnight, but generally this will depend on your recovery.

When can my family or friends visit me at the hospital after my surgery?

Our visiting times are different at every hospital, but overall they are very generous and quite flexible. Speak to your care team ahead of time so you know the visiting hours and also how soon after your surgery they will be able to visit.

How long does it take to recover from arthroscopic surgery?

Your recovery following an arthroscopy will depend on your diagnosis and the procedure used to carry out your surgery. It could take up to three months after your surgery to experience an improvement, but for some people it will be much sooner.

What is the best sleeping position after a knee arthroscopy?

After your operation, you might find it more comfortable to sleep lying on your back or on the side where you did not have your surgery. Placing a pillow in between your legs could make sleeping on your side more comfortable.

How long does swelling last after an arthroscopy?

Swelling after an arthroscopy could last for a few weeks or more. For the first two days after your surgery, you should keep your leg in a raised position when sitting down to reduce swelling. An ice pack can also help with swelling, but you should wrap this in some cloth first before applying it to your skin. It should not be applied for more than 20 minutes at a time and a one-hour break between each application is recommended.

How will physiotherapy be used to support my recovery following a knee arthroscopy?

Physiotherapy exercises after an arthroscopy can support your recovery and gradual return to your normal activities. Your physiotherapist will give you exercises to do before and after your procedure as part of your treatment plan. Recovery exercises after an arthroscopy will include circulation exercises, exercises for your quadriceps (the muscle located in the front of your thigh), knee flexion (bending) exercises and knee extension (straightening) exercises.

You might be asked to repeat these exercises at least four times a day. Knee strengthening exercises can strengthen the muscles surrounding your knee and help expand your iliotibial band (a band of tissue) running down your thigh. Exercises that stretch your quadriceps can boost the flexibility of the muscles located between your hip and knee.

When can I climb the stairs after a knee arthroscopy?

If you need to climb any stairs after your arthroscopy, you should do this one step at a time while holding onto the handrail to support you. At hospital, your physiotherapist will usually show you how to do this. If you need to go up a staircase, step up with your good leg first and use a crutch to step down with your treated leg. But if you need to travel down a staircase, step down with your treated leg and crutch first, and then bring your good leg down.

Can you walk right after arthroscopic knee surgery?

You should be able to walk almost immediately following your arthroscopic surgery. A walking aid such a crutch or walking stick might be needed to support you with walking for the first few days after the operation.

Consultant Orthopaedic Surgeon Mr Paul Nicolai at St Edmunds Hospital answers frequently asked questions (FAQs) about having a knee arthroscopy, including how to prepare for your surgery, what to expect during your operation, and what your recovery timeline might look like.

Why might I need a knee arthroscopy?

Mr Paul Nicolai: A knee arthroscopy can be performed to treat meniscal (cartilage) tears, impingement, and plica syndrome. Plica syndrome happens when your plica (folds of synovial membrane that lubricate the lining of your joints) become attached to the inner part of your kneecap, causing significant knee pain. A knee arthroscopy can also be carried out to take biopsies (a tissue sample), treat defects in your cartilage, and remove scar tissue.

What does knee arthroscopy (keyhole surgery) look for?

Mr Paul Nicolai: After a diagnosis has been made, a knee arthroscopy is usually performed to treat abnormalities in your knee. A diagnosis is based on your symptoms and a knee examination. This could include an X-ray (a scan that allows your bones to be seen) or MRI (a scan that can show your muscles, joints, nerves and blood vessels). However, an X-ray or a scan might not always show the problems affecting your knee. Instead, sometimes these problems are found while performing your knee arthroscopy.

Do I need to undergo any tests or assessments before my knee arthroscopy? If so, what will this involve?

Mr Paul Nicolai: The minimum assessment is a detailed history of your symptoms and a knee examination. You might undergo additional tests such as blood tests, X-rays and scans (an ultrasound, MRI or CT scan).

Will I be required to prepare for my knee arthroscopy? If so, what will my knee arthroscopy preparation involve?

Mr Paul Nicolai: In most cases, knee conditions cause muscle wasting. Therefore, increasing your muscle strength by exercising before your operation helps the recovery process for your surgery. If you have a medical condition such as high blood pressure or diabetes, you will need to ensure these are managed appropriately.

You might also have to stop taking blood thinning medication. It is also best to stop smoking before surgery, as this increases your risk of anaesthetic and surgical complications.

Is knee arthroscopy a major surgery?

Mr Paul Nicolai: Knee arthroscopy is an intermediate surgery. It is often performed as a day case procedure where patients can walk out of hospital on the same day. In most cases, patients can leave hospital without the support of a walking aid.

What is a knee arthroscopy and how is it performed?

Mr Paul Nicolai: Knee arthroscopy is usually carried out under general anaesthetic, but it can be performed under spinal anaesthesia.

At least two small incisions are made (each approximately 5mm in length) to allow a telescope and instruments to be inserted into your knee joint. Stitches are often not necessary. Instead, steristrips (adhesive strips) and plasters are used to close the wounds. A compressive bandage is applied for the early period after surgery.

What are the different methods used to perform a knee arthroscopy?

Mr Paul Nicolai: The operative technique that is used will depend on your surgeon’s preferences, but the basic principle described above remains the same. There is variation in the placement and direction of the incisions, instruments used and wound closure.

Which does anaesthesia for a knee arthroscopy involve? How long can it take for the effects of this anaesthetic to wear off?

Mr Paul Nicolai: Knee arthroscopy is usually carried out under general anaesthetic but can be performed under spinal anaesthesia. The anaesthetic’s effects wear off within a few days.

How long does it take to perform a knee arthroscopy?

Mr Paul Nicolai: The duration of your surgery can vary from about 10 to 45 minutes.

What can I expect after a knee arthroscopy?

Mr Paul Nicolai: After your knee arthroscopy, it is usually recommended that you limit any excessive activity for the first two weeks. Painkillers can help with the pain. Ice and anti-inflammatory medication (when taken safely) can help reduce inflammation. During the first two weeks, the aim of your surgery is to regain knee movements and be able to walk short distances. After this time period, you can increase your activities. However, this will depend on your pain and inflammation.

It can take about a week for your wounds to heal and six weeks for the inflammation to settle. It will take around three months for your muscles to strengthen completely.

How long will I need to stay in hospital after a knee arthroscopy?

Mr Paul Nicolai: A knee arthroscopy is usually a day case procedure, meaning you go home the same day of your surgery.

Can I eat and drink after my surgery?

Mr Paul Nicolai: Patients can eat and drink within a few hours of surgery.

Can you walk right after arthroscopic knee surgery?

Mr Paul Nicolai: In most cases, walking is possible after knee arthroscopy. But for procedures such as meniscal repair, you might need to use crutches to avoid bearing weight on your treated leg.

When can I return to work after a knee arthroscopy?

Mr Paul Nicolai: This depends on your profession, but you could return to work after about two weeks in most cases.

When can I return to sport after a knee arthroscopy?

Mr Paul Nicolai: You might be able to resume low impact sports, such as swimming or cycling, after two to four weeks. High impact sports could be resumed after six to eight weeks. This will depend on the condition that is treated and on how well your recovery goes.

When can I climb the stairs after a knee arthroscopy?

Mr Paul Nicolai: Stairs can usually be climbed immediately after the operation.

How long does pain last after a knee arthroscopy?

Mr Paul Nicolai: There will be some moderate pain and discomfort after a knee arthroscopy. A local anaesthetic is often injected into your knee at the end of the operation to reduce pain. Painkillers, anti-inflammatory medication and ice can all be used to control any pain and discomfort.

When can my family or friends visit me at the hospital after my surgery?

Mr Paul Nicolai: Family and friends can visit within a few hours after surgery.

How long does it take to recover from arthroscopic knee surgery?

Mr Paul Nicolai: It can take a week for your wounds to heal, six weeks for any inflammation to settle and three months for complete muscle recovery.

What will my rehabilitation after a knee arthroscopy involve?

Mr Paul Nicolai: After your knee arthroscopy, a physiotherapist can help by sharing exercises to help you regain movement in your knee and strengthen your muscles. They will also demonstrate how to perform these exercises.

Which physiotherapy equipment will be used during my sessions?

Mr Paul Nicolai: It is often the case that no physiotherapy equipment is necessary, but elastic resistance bands can be used to help with muscle strengthening. A cooling sleeve or ice packs can help relieve any inflammation.

For further information about physiotherapy sessions to support your recovery after knee surgery or to improve your knee pain, book your appointment online today or call a member of our team directly on 0141 300 5009.