What is a Meniscus Root Tear?
Meniscal root tears are characterized as soft tissue or bony root avulsion injuries or radial tears located within 1 cm of meniscus root attachment. They can be either a tear which disconnects the root area completely from the body of the meniscus (complete radial tear) or a disruption of the meniscus attachment directly from the bone (true meniscus root tear) that can cause the whole meniscus to lose its capacity to safeguard the underlying cartilage.
The meniscus is a small, "C" shaped piece of cartilage in the knee joint. Each knee has two menisci, the medial meniscus on the inner aspect of the knee and the lateral meniscus on the outer aspect of the knee. The medial and lateral menisci act as a cushion between the thigh bone (femur) and shin bone (tibia). The main function of the menisci is to improve load transmission. A fairly round femur sits on a fairly flat tibia to form the knee joint. Without the menisci, the area of contact force between these 2 bones would be fairly small, increasing the contact stress. The menisci also provide lubrication, shock absorption, and joint stability.
Meniscal root tears are one of the most common injuries to the knee joint. They occur in younger patients as a result of high energy trauma, but most cases occur in degenerative knees following a minor traumatic event such as squatting or without a specific injury event. If left untreated, meniscal root tears can cause morbidity, altered joint kinematics, and development of early osteoarthritis.
Causes of Meniscus Root Tear
Meniscal root tears can be divided into traumatic or degenerative tears.
Traumatic meniscal root tears normally occur in athletes and young population and are more common in the lateral meniscus. They are caused by either a twisting motion, over flexing the knee joint, pivoting, or sudden stopping or deceleration. Sports such as football, tennis, and basketball involve a high risk of developing meniscal root tears. They often occur along with other injuries such as a torn anterior cruciate ligament, a ligament that crosses from the femur to the tibia.
Degenerative meniscal root tears are usually located in the medial meniscus and typically occur in individuals above the age of 40 years as a result of degeneration of the meniscus with age.
Signs and Symptoms of Meniscus Root Tear
The symptoms of a meniscal root tear include:
- Knee pain when walking
- A popping or clicking sensation felt at the time of injury
- Tenderness when pressing on the meniscus
- Swelling of the knee
- Limited motion of the knee joint
- Joint locking
Diagnosis of Meniscus Root Tear
To diagnose a meniscal root tear, your physician will take a detailed medical history and perform a thorough physical examination of your knee. The McMurray test is one of the important tests for diagnosing meniscal tears. During this test, the knee is bent, then straightened, and rotated. These movements create pressure on a torn meniscus and any clicking sound during this test may suggest a meniscal tear. The most common findings on physical examination include pain with full knee flexion, joint line tenderness, and a positive McMurray test.
Your doctor may order an X-ray of the knee to rule out osteoarthritis or other possible causes of your knee pain. Your doctor may also order a magnetic resonance imaging (MRI) scan to obtain a better view of the menisci and assess the extent of injury. MRI is the imaging modality of choice to diagnose and confirm meniscal root tears and associated pathologies.
Treatment for Meniscus Root Tear
Non-surgical treatment options for a meniscal root tear may include:
- Non-steroidal anti-inflammatory drugs (NSAIDs) to help reduce swelling and pain
- Physical therapy for muscle and joint strengthening
- Injection of corticosteroids at the region of tear to relieve inflammation and pain
- Activity modification/lifestyle changes for weight loss and management of arthritis
If non-surgical treatment fails to provide satisfactory results, your doctor may suggest surgery to repair the torn meniscus root. Surgical management involves either repairing by stitching the root of the meniscus or trimming the root of the meniscus and reestablishing the connection with the bone. Suturing or repairing the meniscus root will need a period of 4 to 6 weeks of crutch use as well as physical therapy. Surgery is arthroscopic in either situation.
Excellent results have been achieved with operative management of the meniscus root. Successful repair can eliminate pain and restore normal function of the meniscus.