What is a meniscus injury?
In the knee, there are two C-shaped cartilage discs called menisci: the medial meniscus (inner side) and the lateral meniscus (outer side). Their job is to act as shock absorbers and stabilizers between the femur and tibia. A meniscus injury means a tear has occurred in the cartilage, often leading to joint irritation.
Meniscus injuries are often categorized as:
- Traumatic injuries: Occur suddenly, often during a sharp twist.
- Degenerative injuries: Occur gradually due to age-related changes in the cartilage.
Common symptoms of a meniscus injury
Symptoms vary depending on the severity and whether the injury is acute or gradual. Common symptoms include:
Symptoms of acute injury
- Sharp pain during specific movements
- Swelling (often within hours or the next day)
- Pain during weight-bearing, especially on stairs or during turns
- Difficulty squatting or fully bending the knee
Mechanical symptoms (locking)
- A feeling that the knee is catching or locking
- Clicking or popping sounds
- Instability or a feeling that the knee is "giving way"
- Difficulty fully straightening the leg
Why do meniscus injuries occur?
Injuries can stem from sports trauma to natural wear and tear:
- Twisting force – The knee is forcefully twisted while the foot is planted.
- Aging – Over time, menisci become more brittle and can tear during everyday movements.
- Repetitive microtrauma – Work involving repetitive strain, such as kneeling frequently.
- Overweight – Increased load on the joint can accelerate wear.
When should you seek care?
Contact a healthcare provider if:
- You have severe knee pain that doesn't subside.
- The knee is swollen and stiff.
- The knee locks so you cannot straighten or bend it.
- You feel unstable and fear the knee will give way.
How to diagnose a meniscus injury
A first step is booking an appointment with a physiotherapist or doctor. They perform clinical tests (e.g., McMurray's test) to provoke symptoms from the meniscus.
If clinical examination is inconclusive, an MRI scan of the knee is the best method. MRI provides detailed images of the menisci, ligaments, and cartilage to determine the extent of the injury.