If you feel a pop in your knee, and experience pain especially when the knee is fully bent or fully straightened, you may have suffered a meniscus tear. Be sure to see your doctor as soon as possible.
A meniscus tear is a tear of the crescent-shaped, smooth, fibrous cartilage structure in the knee between the femur (thigh bone) and the tibia (shin bone). There are two menisci in each knee that face each other and sit on the top surface of the tibia. They form two concave cradles that help cushion weight from the femur above. The meniscus on the outer side of the knee is called the lateral meniscus. The meniscus on the inside edge of the knee is called the medial meniscus. Each meniscus helps cushion and stabilize the joint as the tibia and femur glide past each other during normal weight-bearing activity.
Meniscus tears occur most commonly during active sports, as a result of strong twisting motions to the knee. When the knee is bent and forcefully rotated, the menisci are most susceptible to injury. A meniscus tear may also occur at the time of an associated ligament injury, for example, an ACL tear.
When a meniscus is torn, a pop may be felt within the knee; significant pain in the knee joint is typical. The knee usually swells within a few hours, and the patient often develops a limp. The pain in the knee often increases when the knee is fully bent or fully straightened. Some patients have no immediate pain or swelling. In these patients, symptoms can take several days to appear or may become significant only when the patient tries to do more vigorous activities such as playing sports.
Your doctor can detect a meniscus tear by examining your knee and learning more about the history of the injury. X-rays cannot be used to detect a tear in the meniscus but are often used to identify other problems and injuries to the bones around the knee. A magnetic resonance imaging (MRI) examination may be used to view the meniscus as well as other knee structures.
- Rest . All activities that require active use of the knee should be restricted. Talk with your doctor about a plan for gradually returning to full activity.
- Ice . Ice packs may be used for about 20 minutes at a time, each hour to help alleviate pain and decrease swelling.
- Bandage/Compression Wraps . Your doctor may recommend that you use a soft elastic wrap or bandage at the knee to help reduce swelling.
- Elevation . Elevating the knee should help ease pain and swelling. Ideally, the foot should be elevated higher than the knee, and the knee should be elevated higher than the hip.
- Medication . Your doctor may prescribe an anti-inflammatory or pain medication.
- Knee Brace . Your doctor may prescribe a knee brace to help stabilize the joint.
- Crutches . Your doctor may advise you to use crutches to take pressure off the knee, reduce pain and increase mobility. You should be protected with crutches if weight bearing is painful or if you are limping.
- Physical Therapy . Your doctor or physical therapist may recommend a range of motion and muscle stretching and strengthening program for your knee.
If the meniscus tear causes significant symptoms, surgery is typically recommended. During the surgery, your doctor will typically make several small incisions in the knee that will be just large enough to allow pencil-sized instruments to be introduced into the knee. Your doctor will use an instrument called an arthroscope to view the inside of the knee joint. An arthroscope is a thin tube with a tiny camera at the end through which your physician can view the structures inside of your knee on a television monitor.
Other small arthroscopic tools will be used to either repair the torn meniscus cartilage (meniscus repair) or to remove the torn fragments (partial meniscectomy). Because the meniscus is a shock absorber and is important for the normal long-term functioning of the knee, repair of torn meniscus cartilage is preferable to removing the torn tissue. Clean meniscus tears through healthy tissue that have a good blood supply are amenable to meniscus repair. Tears that are degenerative in nature or lack a good blood supply are usually not repairable.
After partial meniscectomy, recovery is often quite fast and may be complete as early as 6-12 weeks from the time of surgery. Recovery from meniscus repair is considerably slower and may take from 3-6 months. A meniscus that is repaired surgically may not always heal fully and may require subsequent surgery with partial meniscectomy to remove the portion of the meniscus that has not healed fully.