When the meniscus – a cartilage cushion inside the knee joint – becomes torn, it can lead to pain, weakness and other knee symptoms.
What is a torn meniscus?
The knee joint is made up of three bones, the thighbone (femur), shinbone (tibia) and the kneecap (patella). The menisci are two horseshoe-shaped pieces of cartilage that sit between the femur and tibia. They act as shock absorbers for the joint and also provide cushioning and stabilization for the knee joint.
Tears in the menisci are common and often occur while participating in sports.
Causes of a torn meniscus
Torn menisci are caused by trauma – especially twisting of the knee or direct blows –but they may occur as a result of degenerative changes that weaken the cartilage, using due to aging. There are a variety of ways the meniscus can tear. Common types of meniscal tears include bucket handle, flap or radial.
If a torn meniscus is caused by trauma, other knee injuries may occur at that time.
Symptoms of a torn meniscus
Meniscal tear symptoms include the following:
- Locking of the knee joint
- Weakness or inability of the knee to support your body weight
- Limited range of motion
Diagnosing a torn meniscus
Your orthopedic surgeon will perform a physical examination of your knee to determine whether or not you have signs of a torn meniscus. Swelling and tenderness along the joint when touched are signs of a meniscal tear. Popping in the joint with movement may also be noted.
Magnetic resonance imaging – MRI – uses a magnet and pulsating energy waves to produce a 3D image of the inside of the knee joint. MRI can reveal tears in the meniscus.
X-ray may be done to evaluate any degenerative changes in the knee, such as those seen in osteoarthritis. X-ray is not effective in identifying a torn meniscus.
Arthroscopy is a minimally invasive procedure that allows your orthopedic surgeon to look inside the knee. This is used when a cause for knee pain and/ora locked knee cannot be identified through other diagnostic tests. Arthroscopy may also be done to treat a torn meniscus.
Treatment of a torn meniscus
Initially, a torn meniscus may be treated conservatively with R.I.C.E. (rest, ice, compression, elevation) and non-steroidal anti-inflammatory drugs (NSAIDs) to reduce pain and swelling. Crutches and support wraps may be helpful and weight bearing should be avoided, if it is painful to stand. Physical therapy is advised to strengthen supporting muscles and gradually increase mobility.
Surgery may be required if the torn meniscus doesn’t heal after 2-3 months of conservative treatment. Repair is commonly done through arthroscopy, a minimally invasive technique that uses a tiny camera inserted into an incision in the knee to provide visualization for small surgical instruments, which are introduced through additional incisions in the knee.
Depending on the extent of the tear, a partial meniscectomy may be done to remove the damaged portion of the meniscus or the tear may be repaired through suturing.
Rehabilitation after surgery usually includes physical therapy.