Question: Doc, I fell on my leg and twisted my knee while backcountry skiing yesterday. Now, I am unable to completely straighten out my knee, and my knee is swollen and painful. I have a friend who mentioned that I likely tore my meniscus. What is a meniscus and what should I be concerned about?
Dr. Robert LaPrade: Locking, or the inability to completely straighten out one's knee, swelling and pain inside the knee joint are all common signs of a meniscus injury. Other signs to be aware of include the inability to bear weight, a feeling of the joint "giving way" and a clicking noise when you bend your knee.
The meniscus is a "C" shaped piece of cartilage that acts as the major shock absorber of the knee. Each knee has two menisci sitting atop the tibia (shin bone), one on the medial side (inside) and one on the lateral side (outside) on top of the bone. In addition to absorbing shock during normal movements, the menisci also act to distribute weight evenly between the tibia and femur (thigh bone). Injuries to these structures are not only painful and disabling, but can lead to more severe long term knee problems (i.e., arthritis) if they are not properly addressed.
Meniscal injuries are the most common knee injury seen in the general population. Since nearly 45 percent of skiing and snowboarding injuries involve the knee, meniscus injuries are a common problem to be aware of when participating in winter sports.
Meniscus injuries are commonly caused by twisting a knee while the leg is flexed; however, direct contact, such as a fall or tackle, are also often involved. In older people, degenerative tears are more common as the cartilage wears down and thins out over time. Seemingly innocent movements, such as an awkward twist when getting on or off the lift, or catching one's balance while skiing, can be enough to tear the meniscus in older patients.
When the meniscus tears, a piece of it can become loose and drift into the joint space. This often causes locking, or the inability to straighten/bend the knee experienced by patients following an injury. We commonly describe it as a sensation of having to walk with a pebble inside one's shoe.
Meniscus tears often occur in association with other more serious injuries including ACL tears and bony fractures. As these types of injuries can be quite problematic if left untreated, one should seek medical attention and consult a physician as soon as possible to be evaluated with x-rays and a MRI scan if necessary. Immediately following a suspected injury, one should make use of the PRICE (Protection, Rest, Ice, Compression and Elevation) protocol while waiting to see a physician. You can protect and rest your knee by avoiding twisting, turning, or pivoting activities after injury to prevent further damage within the knee. Ice should be applied for 20 minutes at a time, several times a day. To reduce and prevent swelling, compression bandages are helpful, as is elevating the affected knee by reclining with the leg up above your heart.
Though the immediate symptoms of a meniscus tear can resolve if left untreated, and patients can often continue skiing or snowboarding following a tear, one should not ignore symptoms in their knee. Further evaluation is necessary to establish the extent of the injury and determine whether physical therapy, bracing or surgery may be necessary to prevent further injury and restore the joint to a proper functional status. In almost all circumstances, meniscal tears should be repaired, if possible, because of the very high risk of the development of arthritis when a meniscus has to be removed.
Dr. Robert F. LaPrade is a complex knee surgeon with The Steadman Clinic in Vail. He also serves as the Chief Medical Officer at the Steadman Philippon Research Institute.