The menisci are the critical structures of the knee joint. Each knee has two menisci—the medial meniscus and the lateral meniscus. Both are “C” fibrous cartilage cushion pads that attach to the tibia (leg bone) and prevent arthritis. The menisci act as shock absorbers for the knee, assisting in weight distribution across the joint. The medial meniscus is on the inside of the knee joint; the lateral meniscus is on the outside of the knee. While the primary function of the menisci is to distribute forces and prevent arthritis, the menisci also aid the ligaments, such as the anterior cruciate ligament (ACL), to assist in providing knee stability.
Meniscus injuries can occur as a result daily activity, such as repeated squatting over the years, or a sudden twist, or as a result of a sports injury, or a severe fall. Tears of the menisci can vary in size, location, and severity. In more severe cases, a meniscus can tear completely in half or can be damaged to the point that it is barely attached to the leg bone. However, smaller tears may not always result in symptoms. Unfortunately, small meniscus tears may progress over time, and more severe symptoms may result.
Several types of meniscus tears can be presented:
Symptoms and Diagnosis
Meniscus tears may occur gradually, with occasional pain or swelling, or may occur suddenly, usually as the result of a twist, or fall, or injury during sports. Pain and swelling may occur right after the injury or develop over 1-2 days. Many patients complain that their knee feels like it is going to lock up, get stuck, or give way. Knee stiffness may also result.
Dr. Lubowitz will perform a careful history, and physical examination. Tests include bending the patient’s knee while they are lying on their back, and rotating the leg inward to assess for pain or clicking as the leg is straightened. X-rays and an MRI are used to diagnose meniscal injuries and evaluate for other pathology. Tears in the menisci appear as white lines (fluid leaking in to the tear), and are generally evident on MRI. Dr. Lubowitz will discuss your long-term fitness and activity goals so that an appropriate treatment plan can be provided.
Meniscus injuries are classified as a Grade 1 or 2 in milder cases, and for complete tears, they are given a Grade 3. For a Grade 1 or 2 acute tear, early surgery will most likely not be recommended. Instead, rest, ice, anti-inflammatory medications, and physical therapy may be considered.
For Grade 3 meniscal injuries where a complete tear has occurred, arthroscopic surgery will be used to resect (trim) or repair the meniscus. Arthroscopic meniscus trimming is typically performed on small tears and takes less than 30 minutes. Repairs are performed on younger patients, patients with large tears, and patients with ACL tears, based on the location and pattern, and blood supply to the tear. Repairs typically take about 45 minutes and are also performed arthroscopically, on an outpatient basis.
Following arthroscopic surgery to repair a torn meniscus, Dr. Lubowitz will prescribe a thorough rehabilitation program with a goal of allowing a patient to achieve optimal recovery. Therapy will be a progressive process that will slowly work on range of motion, function, strength, and mobility. More than 90% of patients having partial meniscectomy are able to walk normally in less than 7 days, and the majority return to unrestricted activity in less than 4 weeks, while others may heal more slowly and require up to 5 months for full activity. After meniscus repair, return to full sports is typically less than 3 months.