Meniscus Tears (Overview)

The menisci are two C-shaped pieces of cartilage located between the shin bone (tibia) and thigh bone (femur), one on the inner edge and the other on the outer edge of each knee joint. They function as shock-absorbing pads of cartilage that stabilize the knee, equally distribute one’s weight on the knee bones for balance and smooth movement, and support and protect the knee joint. Meniscus tears can lead to altered knee mechanics and accelerated knee joint degeneration.

Acute traumatic tears

Traumatic tears often result from twisting or pivoting activities with load through the knee or from falls or other sporting injuries. A traumatic impact on the knee can result in an isolated meniscus tear or occur with other associated injuries such as ligament or bony injuries.

Degenerative tears

These occur without a specific injury and are often associated with aging or normal wear-and-tear of the knee. They can be associated with knee osteoarthritis. The majority of degenerative tears cause no symptoms.

Tear patterns include:

• Longitudinal tears are vertically oriented tears in the meniscus. Treatment depends on the symptoms, size, and location of the tear.
• Bucket handle tears are large, longitudinal tears where the torn meniscus’s center portion flips into the knee’s center, which appears similar to the handle of a bucket. These tears cause locking of the knee, difficulty walking, and typically require surgery.
• Radial tears extend from the center of the meniscus toward the outer rim. Depending on the extent and location of the tear, surgery can involve either trimming or repairing it.
• Flap tears cause symptoms like catching or locking in the joint, which can be painful.
• Horizontal tears are stable-type tears oriented horizontally. Depending on the symptoms, either nonoperative or surgical treatment is an option.
• Complex tears involve more than one tear pattern. Treatment is either nonoperative or meniscus-trimming surgery.
• Root tears are radial tears located within 1 cm of the meniscus’s attachment to the tibia. If left untreated, root tears can lead to early osteoarthritis.

Common symptoms include a popping or catching sensation, localized pain on the inside or outside joint line of the knee, and pain with twisting activities. Knee motion may be limited, and it may be difficult to walk depending on the type of tear.

Your UCSF Women’s Sports Medicine Center specialist will ask in-depth questions about your symptoms and any prior knee injuries and treatments. They will perform a comprehensive physical exam and use special tests to evaluate the affected knee. Additionally, imaging studies are helpful, such as X-rays to evaluate for arthritis and an MRI to confirm the diagnosis of a meniscus tear.