Meniscal surgery

What is the meniscus?

The meniscus is a C-shaped piece of cartilage that protects the knee joint from movement and shock. It can become damaged by sudden twisting or impact to your knee. The collagen of the meniscus can also wear down over time, leading the meniscus to become thinner, more brittle and more prone to tearing. Each knee has two menisci: lateral on the outside and medial on the inside.

The outer third of the meniscus has a blood supply and is known as the 'red zone'. Injuries to this part of the meniscus may heal on their own, although it is rare for tears to only happen in this area. Except in children and young adults, the rest of the meniscus has little or no blood supply and is called the 'white zone'. If this area is damaged, it is unlikely to heal by itself.

What is meniscus surgery?

Meniscus surgery is an operation to either repair or remove a torn meniscus. If your meniscus is injured by a sudden twist or collision or wears over time and non-surgical treatments aren't effective, an operation can help improve your knee's mobility and stability. 

The type of tear you have determines the type of meniscus surgery that will be most effective. Less serious tears can sometimes be repaired, allowing the cartilage to heal. For moderate to serious tears, the damaged tissue will be removed.

What are the types of torn meniscus surgery?

Most meniscus surgery procedures are carried out via arthroscopy (a keyhole procedure). This involves using a small camera called an arthroscope to see inside the knee joint. There are different types of arthroscopic surgery depending on the severity of your meniscus tear:

• Meniscus repair: A surgeon may be able to stitch up the tear, allowing your cartilage to heal on its own. This is often an option for bucket-handle meniscus tears as the injury runs through the 'red zone' of cartilage and the increased blood flow improves healing.
• Partial meniscectomy: Also known as debridement. A surgeon removes part of your torn meniscus and leaves healthy tissue in place. Smaller tears to the 'white zone' of your meniscus are often treated with this procedure, which is sometimes referred to as "cleaning" the joint. The removed cartilage is unlikely to grow back, but any issues that the loose, torn portion of the meniscus caused should be improved.
• Total meniscectomy: If you do need meniscus tear surgery, your surgeon will make every effort to preserve as much cartilage as possible. For larger or more complex tears, however, in rare cases it may be necessary to remove your whole meniscus.
• Meniscus transplant: Better suited for younger patients, a transplant may be recommended if the existing meniscus has been severely damaged or worn away. It may also be advised as a means of delaying the onset of knee arthritis. Meniscus transplants involve complex surgery and rehabilitation regimes, and the need for further surgery can be significant. As such, meniscus transplant surgery is fairly uncommon, with strict eligibility criteria.

The surgery is sometimes referred to by the type of tear you've suffered:

• Traumatic meniscus tear surgery treats a tear caused by sudden trauma such as a sport injury
• Degenerative meniscus tear surgery treats a tear caused by little or no trauma, usually linked to the menisci weakening with age

You may also see meniscus surgery described by the type or part of the meniscus that it treats, for example:

• Lateral or medial meniscus tear surgery, which focus on the lateral (outer) or medial (inner) meniscus.

In some cases, a small cyst can form next to a meniscus tear. A cyst is usually nothing extra to worry about but can cause discomfort. Meniscal cyst surgery involves removing the torn meniscus and decompressing its cyst.

When would I need meniscus tear surgery?

Meniscus tears are common in people who play sports that involve sudden turns and possible collisions, such as football. You can also injure them through kneeling, squatting or heavy lifting. While you can damage cartilage in your knee in these ways at any age, the risk increases as you get older because the menisci weaken over time. Degenerative meniscus tears can occur with minimal or no trauma. 

Typical symptoms of a tear include:

• Sharp knee pain or tenderness 
• Swelling around your knee joint
• Difficulty straightening or moving your leg
• A popping or locking sensation in your knee

You may be recommended knee meniscus surgery by your orthopaedic consultant based on factors such as the type, size and location of the tear, and your age and activity level. Depending on your condition, they may recommend non-surgical solutions first, such as resting and ice, physiotherapy and pain medication.