Arthroscopic meniscectomy: keyhole removal of torn knee cartilage

Each knee has two menisci. Versus Arthritis explains that they are wedge-shaped pieces of meniscal cartilage between the shinbone and thighbone, one on the inner side of the knee (medial) and one on the outer side (lateral). They cushion and stabilise the joint, which is why they are tough and rubbery. The NHS describes a meniscus tear as a common type of damage to the cartilage in the knee, usually caused by an injury.

A meniscectomy is an operation to remove damaged meniscus. In an arthroscopic meniscectomy this is done through keyhole incisions rather than a large cut. Depending on the tear, the surgeon may trim away the torn part, which is what a partial meniscectomy means, or in some cases remove more of the meniscus. The alternative approach is repair, where the torn edges are stitched together, and the NHS notes that arthroscopy surgery can be used to repair or remove damaged cartilage. Which option is suitable depends on the tear and your circumstances, and your surgeon will discuss it.

The NHS says a meniscus tear usually happens when you twist your knee while playing sport, but it can also happen from more minor injuries such as twisting when standing up. Symptoms include knee pain or tenderness, stiffness or swelling around the knee (which may not start for a few hours or days), difficulty bending, straightening or moving the knee, the knee giving way when you try to stand, and a crunching or clicking feeling when you move it. The symptoms can be similar to sprains.

The NHS lists joints locking among the symptoms for which an arthroscopy may be done to find the cause, and NHS inform lists joint pain, stiffness, swelling and the joint giving way or popping, usually after X-rays, CT or MRI scans have been done first.

Most people start with simple measures. The NHS suggests stopping exercise and resting the knee for the first few days, applying an ice pack wrapped in a towel for up to 20 minutes every 2 to 3 hours, using a bandage or knee support (removed when sleeping), keeping the leg raised on a pillow and taking paracetamol or ibuprofen gel or tablets. After a few days of rest you should try gentle movements. It advises not using heat packs, drinking alcohol, massaging the knee or carrying anything heavy.

It says to see a GP if knee pain is stopping you doing normal activities or affecting sleep, is getting worse or keeps coming back, has not improved after treating it at home, or if the knee is stiff for more than 30 minutes after waking. In many areas you can refer yourself to NHS musculoskeletal (MSK) services for help such as physiotherapy without a GP referral.

Surgery tends to be considered when symptoms persist or the damage is severe. The sources read for this page do not set out detailed criteria for choosing meniscectomy over physiotherapy, so this is a conversation to have with an orthopaedic surgeon or specialist physiotherapist, who will usually review your scan results, your symptoms such as locking and the level of function you want to regain.

You will speak to a nurse about your health and the type of anaesthetic. The NHS lists general anaesthetic, local anaesthetic or a spinal anaesthetic, which may be used for a knee arthroscopy. During the procedure, according to the NHS, the surgeon makes a small cut or cuts in the skin, around 2 mm to 3 mm wide, near the joint, and a tiny camera with a light (an arthroscope) sends images of the inside of the joint to a screen. The surgeon repairs the joint if needed, then seals the cuts with tape or stitches and may apply a dressing.

NHS inform adds that the surgeon may fill the joint with sterile fluid to make it easier to view, uses additional incisions for fine instruments, then removes any problem tissue and excess fluid. The operation can take 30 minutes to 3 hours depending on what is being done, according to the NHS, and 30 minutes to 2 hours according to NHS inform.

After an arthroscopy you go to a recovery room. The NHS says you should be able to go home as soon as you feel well enough, for most people within a few hours, though sometimes you stay overnight. You must not drive after a general anaesthetic, and someone needs to take you home and, according to NHS inform, stay with you for the first 24 hours.

The joint is likely to be painful and stiff at first, and painkillers such as paracetamol can help. You will usually get a written recovery plan covering work, exercise and driving, and may be referred to a physiotherapist for a few weeks. Typical self-care advice from the NHS is to apply an ice pack for 20 minutes every 2 to 3 hours, keep the leg raised when sitting, wear a compression stocking if you are given one and keep dressings dry. NHS inform adds that dressings can usually be removed after 5 to 10 days and that non-dissolvable stitches are removed after a week or two.

NHS inform describes arthroscopy as generally safe but not risk free. Short-lived swelling, bruising, stiffness and discomfort are normal and usually improve over days or weeks. More serious problems are much less common, occurring in less than 1 in 100 cases: a blood clot in a limb (deep vein thrombosis), infection inside the joint (septic arthritis), bleeding inside the joint and accidental damage to nearby nerves, leading to numbness that may be temporary or permanent. The NHS also lists a reaction to the anaesthetic, joint pain, numbness or tingling, blood clots and infection as rare complications.

The NHS advises contacting NHS 111 or the hospital where you had the operation if you have a high temperature or feel hot, cold or shivery, severe or increasing joint pain, smelly liquid leaking from the cut, severe or worsening swelling or redness in or around the joint, or numbness or tingling in or around the joint.

Exercise and physiotherapy are an important part of getting the knee working well after surgery. Your physiotherapist will give you strengthening and movement exercises and advise when to progress. The sources read for this page do not address the long-term effect of removing meniscus on the knee, so if that is a concern, ask your surgeon how much meniscus is likely to be removed and whether a repair is an option for your tear.

In the UK, assessment usually begins with a GP or NHS MSK service, followed by physiotherapy and, if needed, referral to an orthopaedic surgeon. Arthroscopic surgery is carried out in both NHS and private hospitals, generally as a day case. Whatever the setting, ask what the surgeon expects the operation to achieve, which alternatives exist, and what rehabilitation is planned.