A lateral meniscus tear is an injury to the semi-circular cartilage on the outside of the knee joint. Symptoms include tenderness and pain around the outside surface of the knee. Each knee joint has two crescent-shaped cartilage menisci which cushion and support the knee. They can be injured by twisting or a traumatic injury as well as degenerating over time.
Symptoms of a lateral meniscus tear include tenderness and pain around the outside surface of the knee, particularly along the joint line. There is usually swelling which appears within 24 to 48 hours of the injury occurring. Pain will also be felt when bending the knee or squatting down. A doctor or athletic trainer will do a full knee assessment including McMurrays' test to confirm the diagnosis.
Lateral meniscus injury explained
Each knee joint has two crescent-shaped cartilage menisci. These lie on the inside (medial) and outside (lateral) edges of the top of the tibia or shin bone, also known as the tibial plateau. They act as shock absorbers for the knee as well as providing support and stability for the joint. Injuries to either meniscus can prevent normal use of the knee.
The lateral meniscus is less prone to injury than the medial meniscus because it doesn't attach to the lateral ligament of the medial cartilage meniscus attaches to the medial ligament. A tear of the lateral meniscus can occur during twisting movements, direct impact to the knee joint, deep squats or due to degeneration of the cartilage in older athletes.
A cartilage meniscus tear can occur happen in different ways and result in different types of injury. Degenerative Changes may lead to edges of the menisci becoming frayed and jagged. A longitudinal meniscus tear is a tear that occurs along the length of the meniscus. A bucket handle tear is an exaggerated form of a longitudinal tear where a portion of the meniscus becomes detached from the tibia forming a flap that looks like a bucket handle.
Treatment for a lateral meniscus tear would initially be conservative meaning the athlete would try the easy simple things first including rest. If this approach doesn't work then a doctor may recommend surgery.
What can the athlete do?
If there is swelling RICE principles should be applied (rest, ice, compression, and elevation). Gentle exercises to maintain quadriceps muscle strength in the thigh can be done, although care should be taken not to aggravate the symptoms. Wearing a knee support can help protect the joint while it heals. A glucosamine joint healing supplement may be beneficial for healing cartilage injuries.
What can a Sports Injury Professional do?
The first aim of the sports injury specialist will be to correctly diagnose the injury. They may do this by using specific tests for meniscal tears such as a 'McMurrays' test. Once an accurate diagnosis is made the whether to treat conservatively meaning without knee surgery or whether surgical treatment is required.
Conservative meniscus tear treatment
This may be indicated in the case of a small tear or a degenerative meniscus and may involve:
Ice, compression, and recommendation of NSAIDs e.g. Ibuprofen. Try wearing a knee support or brace if the knee feels unstable. Electrotherapy i.e ultrasound, laser therapy and TENS. Once pain has subsided, exercises to increase a range of movement, balance and maintain quadriceps strength may be prescribed. These may include: squatting, single calf raises and later, wobble-board techniques.
Lateral meniscus tear surgery
In the event of more severe meniscal tears such as a bucket handle tear, arthroscopic surgical procedures may be necessary to repair the lesion. The aim of surgery is to preserve as much of the meniscus cartilage as possible. The procedure itself will normally involve stitching of the torn cartilage. The success of the surgery depends not only on the severity of the tear but also on the age and physical condition of the patient. Younger and fitter patients are known to have better outcomes.
Following surgery, a rehabilitative exercise program will be outlined for the patient which may include strengthening and balance training. Full co-operation with the rehabilitative technique will be necessary to maximise recovery. See expert interview with a surgeon on knee cartilage surgery.