The anterior cruciate ligament (ACL) is a band of strong connective tissue in the knee, connecting…
What are meniscal tears?
A tear in the meniscus is a common injury. It can cause pain and swelling of the knee and make it hard to move.
What is a meniscus?
Each of your knees has two menisci - crescent-shaped pieces of cartilage that pad the bones in your knee joint. They act as stabilisers, lubricants and shock absorbers.   The blood supply to the menisci is precarious; the outer edges of a meniscus receive a good blood supply, so therefore tears in this 'red zone' have a better chance of healing than those in the inner 'white zone'. This is important when considering treatment options.
Meniscal tears are most often caused by twisting injuries - a sudden change of direction while running or playing sport that causes the knee to 'twist' while it is bent, putting strain on the menisci. In many cases, a meniscal tear is just one of several problems that follow a knee injury, such as an anterior cruciate ligament injury.
Rarely, a meniscal tear can also occur without any injury, but as a result of gradual wear. This is more common in older people. 
The torn meniscus can cause pain. In addition, fragments of the meniscus can get in the way of the knee's movement. For example: a 'locked' knee happens when a piece of torn meniscus lodges between the bones, preventing the knee from straightening completely.
- Young adults who play sports, especially contact sports such as football (soccer) and rugby;
- Adults over 60 years of age;
- People who kneel or squat frequently (e.g., at work), and;
- People who climb stairs frequently (more than 30 flights a day).
Signs and symptoms
Signs and symptoms of a meniscal tear include: 
- A cracking or popping sound can sometimes be heard when the tear happens;
- Knee pain - sometimes immediately after the injury, and sometimes developing in the hours after the injury;
- Knee swelling;
- Knee stiffness and loss of movement, and;
- Knee 'popping', 'locking', 'catching' or otherwise not working properly, or feeling unusual.
Nearly two thirds of all meniscal tears show no symptoms. 
Methods for diagnosis
Your doctor can suspect a meniscal tear based on your symptoms and a physical examination. They will then decide if an MRI scan should be done. MRI is the best way of diagnosing meniscal tears, especially if surgery is being considered.
Types of treatment
Immediate treatment of meniscal tears aims to ease the pain and prevent further damage. It can involve:
- 'Icing' the knee - applying an icepack to the knee, and;
- Avoiding movement and activity that can strain the knee (such as sport, running, walking up stairs, cycling, dancing).
Further treatment of meniscal tears is divided into three categories - rehabilitation, repair and removal. Deciding between them depends on your age, health and activity level, and on the shape, orientation, depth and location of the tear.  
Until 1948, the meniscus was thought to have no function, and was often removed completely when tears occurred. Then it was discovered that although removing the meniscus relieved the symptoms in the short-term, it led to more knee problems in the long-term.
Today, the aim is to conserve the meniscus as much as possible; therefore, rehabilitation and repair are preferred to removal. Surgery to remove the meniscus (meniscectomy), when performed, usually removes only part of the torn meniscus.
Rehabilitation is the first type of treatment considered for meniscal tears, since it does not require surgery and can, in many cases, be as effective as surgery.   Your doctor can advise you on rehabilitation measures, including:
- Rest and recuperation (for minor tears, this can be enough);
- Avoiding movement and activity that can strain the knee (such as sport, running, walking up stairs, dancing);
- Physiotherapy - physical exercises that strengthen leg muscles to take the load off your knee joint;
- Braces and crutches, to take the load off your knee joint, and;
- Anti-inflammatory and pain-relief medications. 
Repair of the damaged meniscus is normally done by arthroscopy. There are several techniques, including sutures, implants, or both.  Repair is more successful in younger people with certain types of tears. Repair surgery must be followed by a rehabilitation period.
In some cases, open knee surgery is preferred to arthroscopy.
Arthroscopic partial meniscectomy is a very common orthopaedic procedure.  During menisectomy, the surgeon removes any pieces of meniscus that are interfering with the knee's function. They then trim, reshape and repair the meniscus to prevent further tears.
Meniscal tears can contribute to the development of osteoarthritis later in life.
In the short-term, treatment of meniscal tears is usually effective and will allow you to return to your regular activity level within a few weeks or months.
The long-term effect of a meniscal tear depends on your age, and how serious the tear is. Younger people have a better chance of healing than people over the age of 50.