The meniscus is a cushioning cartilage pad in the knee that serves multiple important functions such as providing lubrication, support and stability, and protection to the bones within the knee joint. Each knee has two menisci: one located along the inner edge, and another on the outer edge. They menisci work to ensure knee stability, evenly distribute weight across the knee bones to maintain balance, and facilitate smooth, multidirectional movement.
A meniscus has two zones: the red zone and the white zone. The red zone, located at the outer edge of the meniscus, has a strong blood supply which enhances its self-healing capacity in case of tears. The white zone is the inner portion of the meniscus, it is characterized by a lack of ample blood supply. This makes it less capable of self-repair when torn, and often necessitates surgical intervention.
A meniscus tear is a tear or damage to this cartilage pad. A tear can lead to catching and locking of the knee during movement. 50% of people with an ACL tear also have a meniscus tear. In addition, the forces in a knee joint may be altered and lead to arthritis.
Acute/traumatic tears are caused by an injury typically associated with sports that involve twisting or rotating the upper body while the foot is planted and the knee is bent, or a rapid change in direction. They are common in football, baseball and soccer, but can also occur from a fall. Traumatic tears may be large or unstable. Unstable tears include radial tears, flap tears and bucket handle tears. A tear can also result from heavy lifting.
Degenerative tears are caused by wear and tear with age. As we age, the menisci slowly wear out and thin, making them more prone to tears. In older adults, even a minor movement such as standing up from a sitting position or a slight twist can cause a meniscus tear. These tears cause pain but eventually improve allowing for a return to an active lifestyle without the need for surgery.
The symptoms of a meniscus tear can vary depending on the severity and location of the tear, but common signs and symptoms may include:
- Swelling or Stiffness
- Limited Mobility
- Popping Sensation felt at the time of injury.
- Instability or Giving Way
- Locking of the Knee
Not everyone with a meniscus tear will have these symptoms. Some people don’t even know they have a tear. Others might ignore the injury for years until they start to have significant knee problems. If have knee pain, it is important to make an appointment with Dr. Masi Reynolds to prevent further damage.
Dr. Reynolds will ask about the circumstances of the injury, your symptoms and whether you had any previous knee problems. He will perform an orthopedic examination looking for signs of a tear. He may manipulate the knee and leg in different positions to test knee strength, mobility, and to see if certain movements cause pain or other symptoms. Special tests like the McMurray’s test, Apley’s test, or Thessaly test can help a doctor determine if a meniscus tear is likely.
When a meniscus tear is suspected, especially when you have an ACL tear, Dr. Reynolds will order imaging studies to confirm the diagnosis and assess the damage. This will include an MRI to view detailed images of the soft tissues including the menisci, and X-rays to view the bones to rule out fractures and osteoarthritis which can cause similar symptoms.
If the diagnosis is uncertain, he may perform arthroscopy, a minimally invasive procedure to look inside the joint to evaluate all the knee structures and provide a definitive diagnosis. Sometimes a tear can be repaired at the same time. It is important to understand that early diagnosis and appropriate treatment can prevent further damage and complications from a meniscus tear.