A lateral meniscus tear is an injury to the semi-circular cartilage on the outside of the knee joint. It can occur suddenly from twisting or a traumatic injury. Or it may develop gradually through wear and tear.
Medically reviewed by Dr. Chaminda Goonetilleke, 10th Dec. 2021
Lateral knee meniscus tear symptoms
Symptoms of a lateral meniscus tear will vary depending on whether your injury is an acute, sudden onset injury resulting from direct impact, trauma or twisting. Or whether your pain has developed gradually over time through wear and tear.
Acute meniscus tears occur suddenly. You will know a specific time when your injury occured. Symptoms are:
- Sudden pain at the time of injury.
- The outside surface of your knee will feel tender when pressing in, particularly along the joint line.
- Your knee is likely to swell up either immediately, or within 24 to 48 hours.
Chronic meniscus injuries develop gradually over time. You will be unlikely to pinpoint precisely when your injury occurred. In children particularly, meniscus tears may be difficult to diagnose as pain may be vague and difficult to pinpoint. Symptoms may include:
- Swelling, pain and tenderness along the joint line on the outside of your knee.
- Pain when bending your knee or squatting.
- You may experience a snapping or clicking sound when bending your knee.
- You knee may also lock.
Your doctor or physio will perform a full knee assessment. This includes specific assessment tests to confirm the diagnosis. For example, McMurray’s test and Apley’s test.
McMurray’s test is often used to indicate cartilage injuries. With the patient laying on their back the therapist holds the knee with the upper hand and the heel with the lower hand. The therapist then applies a valgus (inward) stress to the knee whilst the other hand rotates the leg externally (outwards) and extends the knee. Pain and/or an audible click while performing this maneuver can indicate a torn medial meniscus.
Apley’s test is also used in cases of suspected meniscus tears. The patient is positioned on their front with the knee bent. The therapist grasps the heel and ankle and applies a compressive force through the lower leg. At the same time, they rotate the lower leg. Any reproduction of symptoms, pain or clicking is a positive response, suggesting a torn meniscus.
An MRI scan may be needed to confirm the diagnosis and extent of the injury.
What is a Lateral meniscus tear?
A lateral meniscus tear (torn meniscus) is a tear of the semicircular fibrous cartilage discs in the knee.
Each knee joint has two crescent-shaped cartilage menisci. These lie on the inside (medial) and outside (lateral) edges of the top of your tibia (shin bone). This part of the tibia is also known as the tibial plateau.
The menisci (plural of meniscus) act as shock absorbers for the knee. They also provide support and stability for the knee joint. Injuries to either the medial meniscus, or lateral meniscus can prevent your knee from functioning properly.
The lateral meniscus is less prone to injury than the medial meniscus. This is because it doesn’t attach to the lateral knee ligament in the same way that 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, particularly in older athletes.
Types of meniscus injury
There are different types of meniscus tear:
Degenerative Changes may lead to the edges of the menisci becoming frayed and jagged.
A longitudinal meniscus tear is one that occurs along the length of the meniscus.
A bucket handle meniscus tear is an exaggerated form of a longitudinal tear. Here a portion of the meniscus becomes detached from the tibia. As a result a flap that looks like a bucket handle is formed.
Sports Physiotherapist Neal Reynolds explains torn cartilage meniscus:
Lateral meniscus tear treatment
Treatment for a lateral meniscus tear is usually conservative to begin with. This means without surgery and consists of a period of rest with rehabilitation & strengthening exercises.
If your knee is swollen the the PRICE principles should be applied (protection, rest, ice, compression, and elevation). Ice can be applied for 10 to 15 minutes every 2 hours initially. You can reduce frequency as your symptoms improve.
Wear a knee support to help protect your knee joint while it heals. A stabilized knee brace has additional springs down the sides to give your knee extra support.
If you have a particularly severe injury then a full hinged knee brace may be more appropriate.
Gentle exercises to maintain quadriceps muscle strength can be done. However, take care not to aggravate your injured knee.
Once pain has subsided, the therapist will advise on mobility exercises to increase the range of movement at the knee joint (if needed), along with strengthening, propriception and functional or sports specific exercises should be done.
Seek professional medical advice as surgery may be indicated, especially in active sports people, or if your knee locks or gives way.
Lateral meniscus tear surgery
If the conservative approach doesn’t work then your doctor may recommend surgery. Orthopedic Surgeon Mr. Richard Villar explains knee cartilage surgery below:
If you have a more severe meniscus tear such as a bucket handle tear, arthroscopic surgical procedures may be necessary to repair it. The aim of surgery is to preserve as much of your meniscus cartilage as possible.
The procedure itself normally involves stitching the torn cartilage. The success of the surgery depends not only on the severity of your tear but also on your age, and physical condition. Younger and fitter your are, the better the outcome is likely to be.
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 maximize recovery.
Read more on knee meniscus rehabilitation.