The torn meniscus: Treatment options
This information document outlines the treatment options for injuries to the meniscus
What is the meniscus?
The meniscus is a small C-shaped piece of tissue in the knee, generally referred to as ‘the cartilage,’ that lies between your thigh bone (the femur) and your shin bone (the tibia). It acts as a shock absorber within the knee when walking, running and bending. Each knee has an inner (medial) and outer (lateral) meniscus which can tear.
How does the meniscus tear?
It most commonly tears by twisting the knee while the foot is planted on the ground. This may be from sports injuries or simply squatting and twisting.
What are the symptoms of a tear?
The symptoms include
- Pain is the main symptom, felt typically in the inner or outer sides of the knee as the torn fragment catches in the knee when twisting or turning.
- Swelling due to inflammation within the knee.
- Locking or catching due to a piece of torn meniscus getting trapped in the knee.
What is the treatment for a tear?
There are three options for treating a torn meniscus, depending on the location and the extent of the tear.
- Non-Surgical Treatment
- Surgery: Partial menisectomy
- Surgery: Meniscal repair
Some tears do not cause symptoms after a few weeks and therefore do not need an operation. It is safe to wait a while, taking simple painkillers and trying physiotherapy. If your knee is not swelling up and does not hurt, then no further treatment is necessary.
What is involved in surgery?
Surgery involves a relatively minor procedure called an Arthroscopy, performed as a day case under general anaesthetic. Two or three small one centimetre cuts are made in the knee and a camera is inserted to inspect the damage. Instruments are then used to treat the torn area, either removing the torn fragment or repairing it.
Is it removed or repaired?
Most tears are small and in the ‘white zone’ (see picture) where there is no blood supply to help them heal. The torn portion is trimmed away as a ‘partial menisectomy,’ leaving most of the meniscus to do its job protecting the bone surfaces.
However, if the tear is large, and in the ‘red zone,’ then it is better to repair the tear – by meniscal repair. If such a large torn fragment is removed, there is a higher risk of arthritis developing later on.
How do you know if I need a partial menisectomy or meniscus repair?
The knee specialist will explain what the options are. It is hard to predict which tears can be repaired and the final decision is made when you have your arthroscopy.
What happens after a partial menisectomy?
Your knee will be swollen and sore for about two weeks. Crutches may be needed for a few days but sporting activities can start around two weeks. It is advised to take one week off desk work and two weeks off manual work. You can drive 3 – 5 days after the operation, as soon as able to do an emergency stop.
The whole recovery period can take up to six weeks. Recovery is a few weeks longer for treating lateral (outer) tears than following medial (inner side) tears.
What is involved in meniscal repair?
If the tear is large and within the ‘red zone,’ where there is a blood supply, then the torn portion can potentially be stitched back in place using special stitches inserted during the operation. These hold the edges together while the body does the healing. Sometimes a small cut at the side of the knee is required to ensure a good repair.
Unfortunately it takes longer to heal and recover than a partial menisectomy. It needs time for the knee to be strong enough to tolerate the high loads that go through the knee in sport.
What is the success rate of repair?
Approximately 8 out of 10 tears repairs will heal well – it depends on the type of tear. If it doesn’t heal then further surgery may be needed to remove the fragment that has not healed.
What happens after meniscal repair?
Rehabilitation is supervised by your physiotherapist and the guiding principle is to avoid twisting movements until the meniscus heals strong enough – otherwise it may re-tear, resulting in further surgery. You can drive four weeks after the operation. Returning to work depends on occupation as the knee is protected in a knee brace. Sedantary desk work can be resumed after one week, but return to manual work will take 6-12 weeks.
Knee brace: Your leg will be in a supportive knee brace holding the knee straight whilst walking for four weeks. When sitting, the hinges on the brace are unlocked and the knee can bend up to 90 degrees (a right angle). When resting the knee brace should be removed and the leg can be open to the air.
After four weeks: The brace is removed and you are allowed to fully bend the knee. You should not squat on the knee for at least three months.
When can I return to sport after repair?
Cycling and swimming can start after four weeks, but running only after three months. Sports involving fast twisting should be avoided for four to six months. This time period needs to be checked with your surgeon as it can vary.
What are the risks and complications of meniscus surgery?
As with any surgery, there are potential risks. Complications can include infection, blood clots in the leg, and damage to blood vessels or nerves within the leg, but these are very rare.
Written by Anita D’Mello and Jon Corns, Medical Students, University of Warwick, and the knee consultants at University Hospital Coventry: Tim Spalding, Mark Taylor and Peter Thompson.