Knee arthroscopy is one of the most commonly performed operations. It involves using a high-definition camera to see inside the joint. This is done through small puncture wounds in the skin. In addition to the camera, other instruments can be used to work inside the knee. Arthroscopy has gained popularity over the years. It is has a faster recovery time, minimal scarring and low levels of post-operative pain…
Many people have heard the term knee arthroscopy. Not everyone has a good understanding of what is involved, however. An arthroscopy is a valuable tool for assessing the inside of the joint. In it’s earlier days the procedure was used to diagnose painful conditions. Nowadays the use of arthroscopy simply for diagnosis is not widely accepted. Arthroscopy is mostly used to perform a therapeutic procedure once the diagnosis is known. Knee arthroscopy as a diagnostic tool is used only in the rare instance when a diagnosis cannot be made, despite having all the necessary investigations such as an MRI scan.
What procedures can be performed arthroscopically?
There are a number of procedures which can be performed arthroscopically. The simplest procedures include washing out the joint in cases of infection. Arthroscopy is commonly used to fix or remove a torn cartilage (meniscus tear). (Read: Knee Pain from a meniscal tear and Three signs that you may have a meniscus tear). Loose or foreign bodies may be removed. It is also used to perform a microfracture procedure when there are areas of deep cartilage injury in an otherwise healthy knee. In this procedure small holes are made to small areas of full-thickness cartilage defects to encourage a type of cartilage “repair”. More complex procedures can also be performed arthroscopically. These include ACL and MPFL reconstructions. ACL reconstructions involve replacing the torn anterior cruciate ligament in the knee with a graft to restore knee stability. An MPFL reconstruction is used for a recurrent patella (knee cap) dislocation.
What is involved in a knee arthroscopy?
Knee arthroscopy is performed as a day-case procedure, unless the arthroscopy is part of a larger procedure. An arthroscopic ACL reconstruction, for example, usually involves a one-night stay in hospital.
Anaesthetic for knee arthroscopy
Arthroscopy is normally done under general anaesthetic. This means that you will be in a deep sleep. Your breathing will be controlled by the anaesthetist. It is possible to do an arthroscopy under a spinal anaesthetic – this involves an injection into the lower back which numbs the legs. If a spinal anaesthetic is chosen a light sedation may be given. This will allow you to sleep lightly during the procedure. Other anaesthetic methods are used less commonly.
The advantage of the general anaesthetic is that you may be mobilised (start walking) almost immediately after the procedure and can begin to use the leg straight away. With a spinal anaesthetic you have to wait until the anaesthetic wears off, and this can be several hours. Sometimes the anaesthetic only wears off the next day – this can result in prolonged immobility in bed and in turn this can increase the risk of developing a blood clot (DVT).
Procedure for knee arthroscopy
There are many different techniques for performing an arthroscopy. My preference is to have you lie flat on your back (supine) on the operating table in a comfortable position – I do not use a leg holder. I use a tourniquet on your thigh to control bleeding and improve vision (a tourniquet is not always necessary, and is sometimes not used). The tourniquet is inflated once you are asleep and is deflated as soon as it is not needed.
The first step in a knee arthroscopy is to fill the joint with fluid called normal saline. The fluid expands the joint and makes it easier to use the instruments inside the knee and helps to prevent inadvertent damage to the cartilage in the knee.
A high-definition camera is inserted through a small hole in the skin. For a routine knee arthroscopy usually just three small holes (or portals) are needed. I use local anaesthetic on the skin where the portals are made before I make the small cuts – this helps with post-operative pain control. The first portal is an inflow portal to allow the water (normal saline) to flow into the knee. This is made just above the kneecap. The second portal is below the kneecap towards the outside of the knee. This is for the camera. The third portal will be just below the kneecap, on the inner side of the knee. This will be for the instruments. Any and all of the skin portals may be used interchangeably for the camera or instruments as described above.
One of the most important aspects of knee arthroscopy is to be systematic. This is important in order not to miss anything. I perform the same routine every time. I make a thorough inspection of all compartments and spaces of the knee. I do this even if I know that certain structures are expected to be normal. This is also useful to document the status of your knee.
After the procedure
After the arthroscopy I infiltrate the surrounding tissues with local anaesthetic to assist with pain control. The fluid is drained from the knee. In most instances you will not have a drain of any sort. The skin portals are stitched closed. I use a dissolving stitch which is placed underneath the skin – this does not need removal. Occasionally, I may use a nylon stitch which is removed ten days later.
I use a waterproof dressing over the stitches. After this I apply a compressive stocking to control swelling. This also reduces the risk of a blood clot (DVT). It is called a TED stocking. I then apply a comfortable wool and bandage dressing to the knee which can be removed after 48 hours.
Once you have woken up from the anaesthetic you are transferred to the ward for observation. When you are comfortable and have had something to eat and drink and you do not have any nausea you will be seen by the physiotherapist. The physiotherapist will help you to get out of bed and go to the bathroom. If necessary they will help you to use stairs as well. For a routine arthroscopy, patients are discharged on the day of surgery.
Can you walk after arthroscopic knee surgery?
In most cases, yes. For a routine arthroscopy to remove a torn cartilage you are able to walk immediately after the operation. Walking is, in fact, encouraged. Most people are able to walk without needing to use crutches.
If you have had an ACL reconstruction you may put weight on the leg. It is usually a bit more painful and so crutches are generally required after this procedure. Crutches are also needed if you are not allowed to put any weight on the leg at all (for example if you have had a meniscus repair, either alone or in conjunction with an ACL reconstruction). The physiotherapist will teach you how to use the crutches correctly.
What can I expect after arthroscopic knee surgery?
Arthroscopic knee surgery generally has good outcomes with quick recoveries, as long as the indication is correct. After the surgery you may experience mild discomfort or aching in the knee. This is usually well-controlled with the oral painkillers that we prescribe for you. Most patients, however, have very little pain after the procedure.
You may notice some swelling in the joint in the days afterwards. This is a combination of the residual fluid from the arthroscopy and a small amount of bleeding. This is nothing to worry about. If it is excessive it can be drained at your first follow-up visit. Otherwise the body normally re-absorbs this fluid in the days and weeks after the surgery. If there is a continuous leak or bleeding from any of your wounds which does not settle after a day or two then you should be seen and have this addressed sooner.
You can take your wool and bandage dressing off after two days. The sticky plasters should stay on until your first post-operative visit at ten days. Although the dressings are waterproof you should not let knee get wet. I encourage you to wear your stockings for the first two weeks after the operation.
Follow-up for knee arthroscopy
You will see me at 10 days for a follow-up appointment. The wounds will be checked and your range of movement tested. I will also check for any complications such as a blood clot (DVT), excessive swelling in the joint and infection. Fortunately these complications are rare.
If necessary you will be referred to the physiotherapist for further strengthening and rehabilitation. I usually see you again at the six-week point to check on your progress. Patients often don’t come to this appointment as many have recovered fully by this stage.
Is arthroscopic knee surgery painful?
Arthroscopic knee surgery is generally not very painful. As with any surgery there will always be some level of discomfort afterwards. I inject local anaesthetic both before and after the procedure to the areas likely to cause pain. This, in combination with the pain medications prescribed by the anaesthetist, results in a very comfortable patient experience. Many of my patients do not even use the painkillers they were given at home, or they use them only for a day or two.
Having said this everyone has a different pain threshold and some patients do experience some pain. Fortunately this is usually not severe and is easily controlled.
How long does it take to recover after arthroscopic knee surgery?
This depends on what you do. I always advise patients to take at least a few days off to rest after the procedure. If you work in an office you may go back to work as soon as you are comfortable to do so. If your work involves more activity or manual labour it may take four to six weeks to get back to work. Many patients are already back at work before the first follow-up appointment at ten days. The remaining patients usually start work again soon after that. By 6 weeks most have settled but it is not uncommon for mild residual pain and swelling to be present up to 3 months after the operation.
Many people are keen to get back to exercise and sporting activities. I recommend that you do not try to jog until at least four weeks. If you have been told to be non weight bearing you will usually need crutches for 6 weeks, and so your recovery in terms of walking will therefore be longer. If you have had an ACL recontruction, you should be able to walk comfortably without crutches by between 4 to 6 weeks. It will take longer to be able to jog in a straight line (4 months) and return to sport (9 months).
Yours in good health,
MB BCh (Wits), MRCS (England), MMed (Ortho Surg), FC Orth (SA)
Orthopaedic Surgeon
(011) 304 6784
About the author…
I am an orthopaedic surgeon with a special interest in sports injuries and minimally invasive (arthroscopic) surgery of the knee and shoulder. I treat patients at Waterfall Hospital in Waterfall/Midrand and Morningside Mediclinic in Sandton. Besides these, I also treat patients from other areas as well, including Rosebank, Sunninghill and Fourways.
Get in Touch
Please use the form below to get in touch with Dr Matthee’s rooms.
