Is Your Knee Pain a Torn Meniscus?
Written by: Andrew F. Rocca, M.D.
Essential for mobility and often over utilized, the knee joint becomes susceptible to problems and injury. One type of knee injury commonly seen in an orthopaedic clinic is a meniscus tear. The knee is made up of three bones: the femur (thigh bone), the tibia, (shin bone) and the patella (knee cap). The meniscus, is a half moon-shaped, wedge-like cushion that lies between the bones in your knee joint allowing your weight to be equally distributed across the bones. Made up of cartilage, the wedges not only stabilize the knee, but also allow the joint to smoothly slide and move in many directions. When the meniscus is torn or damaged, you lose part that cushioning system; your weight is no longer applied evenly across your bones, so grinding and wearing occurs as bone meets bone. After time, arthritis of the knee joint develops as the stressed bones take on more of the burden of your weight.
Meniscus tears are most commonly caused by trauma (athletic injuries) and the aging process (as we age our cartilage becomes brittle.) When the injury occurs in athletes, the patient typically describes a “popping” sensation in their knee when participating in a sporting event. Surprisingly, most people are still able to walk after tearing their meniscus, and we often see athletes return to the field after this type of knee injury. The seriousness of the injury is not apparent until later when the knee becomes inflamed, feels painful, tight, and may be quite swollen.
Symptoms of a Torn Meniscus may include (but are not limited to):
• knee pain;
• knee swelling, commonly referred to as “water on the knee,” or technically an “effusion;”
• hearing a popping or clicking within the knee; and
• limited motion of the knee joint.
Treatment after initial injury should follow the RICE formula (Rest, Ice, Compression, and Elevation.) If the knee recovers fully after RICE treatment, then no other treatment may be necessary. However, if there are still problems with the knee, a piece of the meniscus may be torn or loose and floating around inside the joint causing the knee to lock, slip or pop. In some cases, the knee will catch or lock and the patient will have to manually manipulate the joint to straighten it. Unlike the athletes, older folks often don’t experience trauma when they injure their meniscus. Instead, the wear and tear on the joint over the years weakens the meniscus until one day a degenerative tear appears. If you think you have a torn meniscus, you should see your doctor to have this evaluated further.
Your exam will include your physician taking a careful history of your symptoms, palpating the joint, and noting areas of tenderness. X-rays and a MRI may also be ordered by your physician to better visualize what is occurring inside your joint. If a meniscus tear does appear on your MRI, the next step is to determine treatment, and most pointedly, whether or not surgery is indicated. Sometimes an individual is not a good surgical candidate or their meniscus tear symptoms are minimal, in this case we can take a “wait and see” approach. Surgery is sought when the knee becomes problematic and interferes with day to day activities.
If surgery is indicated, your surgeon will recommend either a meniscus repair (repairing the tear) or a partial menisectomy (trimming and removing the torn or loose pieces of meniscus in your joint), based on your specific injury. A meniscus repair is an attempt to fully restore the structure, and because it is a more extensive surgical procedure requires a longer recovery. The failure rate is higher with meniscus repair because the delicate meniscus tissue lacks an adequate blood supply and does not heal well. If the repair is successful however, the joint is healthier in the long run. When the injured tissue has completely lost its blood supply or is tattered beyond repair, a partial menisectomy is performed. Menisectomy quickly relieves the most bothersome symptoms, has a faster recovery than meniscus repair, but, because a portion of the knee’s cushioning is removed, will not reduce the risk for further progression of arthritis.
Both meniscus repair and partial menisectomy are arthroscopic surgeries. The arthroscope gives your surgeon a clear view the interior of your knee with the benefit of only a couple of small incisions (each, approximately one centimeter in length). Using tiny instruments your surgeon can trim frayed areas, suture tears, and remove fragments of the meniscus that have broken loose. The outcome of the surgery depends on several factors, including the severity of the particular injury, the degree of damage, and associated arthritis. As mentioned earlier, recovery is dependent on the type of surgery (repair vs. partial menisectomy) but most report only needing a couple of days off from work until they are up again. Further recovery and return to more aggressive activities or physical labor, however, often takes longer and physical therapy may be beneficial for recovering full function of the knee in the 6-8 weeks following surgery.
Please note that although arthroscopy can effectively treat many problems, you may have some activity limitations even after recovery. A return to intense physical activity should only be done under the direction of your surgeon.