Home / Conditions / Torn meniscus
The meniscus is a C-shaped cushion of cartilage between the thigh bone and the shin bone — there are two in each knee. A tear can come from a twisting injury or, in older knees, simply from wear. Which kind it is decides the treatment, and many tears never need an operation.
A torn meniscus is not one thing. How the tear happened, and what it is doing to the knee now, matter more than the tear itself — and they point to quite different treatment.
| Injury tear | Wear tear | Locked knee | |
|---|---|---|---|
| Who it happens to | Younger, active people, often in sport | Usually over about forty, often with early arthritis | Any age |
| How it came on | A twist on a bent, weight-bearing knee, sometimes with a pop | Gradually, or after something minor such as squatting | A torn flap flips into the joint |
| What it does | Pain on one side, swelling over a day, catching | Aching on one side, stiffness, occasional catching | The knee cannot straighten fully |
| What usually helps | Rehabilitation, and a repair if the tear can be stitched | An exercise programme first; keyhole trimming rarely helps more | Prompt assessment; often keyhole surgery to free it |
A knee that is locked and will not straighten should be seen within a day or two. A torn flap caught in the joint is easier to deal with early, and leaving it can damage the cartilage further. Call the clinic and come in.
Each knee has two menisci, one on the inner side and one on the outer, sitting on top of the shin bone. They spread your weight across the joint and help keep it steady. The inner one is torn more often.
What a picture cannot show is where a tear can heal. Only the outer rim of the meniscus has a blood supply. A tear there can heal, or be stitched; a tear in the inner part cannot, which is why some tears are repaired and others trimmed.
It also explains why the meniscus is worth saving. It is the knee's cushion, and removing part of it raises the load on the joint surfaces, making arthritis more likely years later — so repair is preferred where it is possible, and trimming is kept to the minimum.
Treatment depends on the kind of tear, where it is, and what the knee is doing. The aim is to settle the pain and keep as much of the meniscus as possible.
For the first few weeks, avoid twisting and deep squatting, use ice for swelling, and take the weight off with crutches if walking is painful. Many tears settle considerably in this time.
A structured programme to strengthen the muscles around the knee. For wear tears, trials have found it does as well as keyhole surgery, so it comes first. Many injury tears settle with it too.
A tear on the outer rim can often be stitched back together through keyhole surgery. It is preferred where possible, particularly in younger people, because it saves the meniscus. Recovery takes about three months, while the tear heals.
A torn flap that catches or locks the knee, and cannot heal, can be trimmed away through keyhole surgery. Recovery is quicker, usually a few weeks, but as little as possible is removed, since the meniscus protects the joint.
Torn meniscus here is seen by Dr Kelvin Tan Guoping, an orthopaedic surgeon whose subspecialty is hip and knee, and whose practice includes trauma and sports surgery. He is a Fellow of the Royal College of Surgeons of Edinburgh, holds a Master of Medicine in orthopaedics, and is an Adjunct Assistant Professor at NUS. He consults in English, Mandarin, Teochew and Hokkien.
A tear on the outer rim sometimes can, because that part has a blood supply. Tears in the inner part do not heal, but many still stop causing trouble once the swelling settles and the muscles around the knee are strengthened.
Often not. Surgery is usually for a knee that locks, a tear that can be repaired, or symptoms that persist despite proper rehabilitation. For wear tears in older knees, exercise does as well as surgery.
If the pain comes from a wear tear alongside early arthritis, usually not — trials have found trimming does no better than an exercise programme. It helps most when a torn flap is catching or locking the knee.
After trimming, most people are walking normally within days and back to most activities in a few weeks. After a repair, it takes about three months, because the stitched tear has to heal.
Yes, sometimes. Some children are born with a meniscus shaped like a disc rather than a C, which is more likely to tear and often shows up as a knee that clicks, catches or locks.
No. Bring any X-ray or MRI reports, and be ready to say how the pain started.
Knee pain · ACL injuries · Knee osteoarthritis · Knee bursitis
Be ready to say how the pain started. A twisting injury and a gradual ache usually mean different tears, and different treatment.
