The menisci are two C-shaped cartilages in the knee joint that aid in joint force absorption as well as provide some stability. There is a medial (toward the other knee) and lateral (away from the other knee) meniscus and these are commonly called the “soft cartilage” of the knee (as opposed to the articular cartilage which covers the end of the bones and acts as the primary cushioning.
The medial and lateral menisci serve primarily as shock-absorbers and cushioning but also aid in stability and proprioception of the knee. Meniscal tears can vary in degree of symptoms and may range from be asymptomatic (usually degenerative tears in arthritic knees) to debilitating pain (usually acute displaced tears). Although meniscal tears can occur with sports or twisting injuries, most present with no discernable cause other than an awareness of knee pain.
Meniscal tears often cause pain that is localized to the sides of the knee and less often may have clicking or a catching sensation. Some meniscal tears will cause knee swelling but this is not always the case.
A physician with expertise in knee injuries is able to accurately diagnosis a meniscal tear with a combination of a detailed medical history, physical examination, and imaging tests. Physical examination is very important to help diagnosis if the cause of your knee pain is a meniscal tear but also to evaluate for other causes, such as arthritis, cartilage inflammation, or tendon/ligament injuries.
An x-ray is usually the first imaging study to evaluate and exclude other causes, such as arthritis, fractures, patellar malalignment/tilt. If the physician feels your symptoms may be from a meniscal tear, an MRI is often ordered to evaluate.
Treatment options vary for meniscal tears and surgery is not always needed depending on the type of meniscal tear and whether there are other underlying causes for knee pain (usually arthritis). Although surgery is the definitive procedure to “heal” a meniscus, some tears may become asymptomatic with non-operative treatments.
Non-operative treatments consist of rest with activity modifications, intermittent icing, nonsteroidal anti-inflammatory drugs (NSAID), and cortisone injections. Physical therapy and home exercises may help as well. Usually these measures are attempted first if there is a degenerative, non-displaced meniscal tear.
Surgery is often required for symptomatic tears in isolation of other knee pathologies (no arthritis). Surgery is usually performed arthroscopically (2 or 3 small 1 cm incisions) with the use of a camera and small instruments to either debride/remove (partial menisectomy) the tear and in some cases, repair/sew the meniscus. The determination for performing a partial menisectomy versus repair is primarily based on the location of the meniscal tear. The menisci primarily only has a blood supply in the outer third and hence a potential ability to heal the tissue. The vast majority of tears unfortunately occur in the inner/central aspects of the menisci and thus lack the ability to heal if sewn together. Surgery is an outpatient ambulatory procedure and usually takes less than 30 minutes to perform. Postoperatively, some patients opt for physical therapy however this is not always needed and home exercises and time allow for full recovery.