Knee (Meniscal) Cartilage Tear

CONDITION

Meniscal cartilage is the smooth, tough, rubbery, half-moon-shaped tissue that lines your knee joint. It helps the knee bones glide easily over each other, absorbs shock and acts to stabilize the joint. The knee joint contains an inner (or medial) meniscus and an outer (or lateral) meniscus (Figure 1).

  • The medial meniscus is torn much more often than the lateral meniscus.
  • There are many shapes and sizes of meniscal tears and some cause more problems than others.
  • Small tears that stay in proper position within the knee can often be treated without surgery.
  • Repair of more complicated large tears, especially if they move and are loose in the joint, requires surgery.
    Figure 1.

CAUSES

Meniscal tears can occur due to injury or may result from gradual wear.

  • The most common cause of meniscus tears is knee twisting, especially with rapidly changing direction (pivoting and cutting) or falling during sports.
  • Squatting positions or getting up from a squat, especially when the knee is fully bent, can cause a meniscus tear without an obvious injury.
  • Meniscus cartilage degeneration, the slow wearing out of tissue over time, can lead to tears.

SYMPTOMS AND SIGNS

If the tear results from an injury:

  • You will have sudden pain over the side of your knee joint where you tore the medial or lateral meniscus.
  • There is often (but not always) swelling and tightness throughout the entire knee that makes bending it shortly after the injury difficult.
  • Your knee may be locked or difficult to move from a fixed position or you may have a catching sensation within the joint if you can move it.
  • Your knee pain will likely get worse with attempted squatting or deep knee bends.
  • Your knee may give out when you try to walk.
  • You may hear a snapping or popping noise at the time of the injury.
  • You may notice that your knee won’t bend or straighten as fully as your uninjured knee.

If the tear results from wear over time:

  • You may notice general aching in the knee or at the joint line with weight-bearing activities, especially those that involve impact (such as running and jumping), and with twisting or squatting.
  • You may have mild knee swelling that comes and goes.
  • You may not have had an injury related to your knee pain. Your knee may be stiff from time to time.
  • You may occasionally feel like something in your knee joint is catching, although this happens much less often than after an acute injury.

WHEN TO CALL YOUR DOCTOR

If you have been injured, call your doctor right away (day or night) if:

  • You have severe pain, swelling, redness or warmth in your knee.
  • You can’t bend or straighten your knee fully.
  • You can’t put weight on your knee.
  • You heard or felt a loud pop when you were injured.
  • Your knee gives out or buckles, gets locked or something catches in the joint when you try to walk.
  • You have numbness, tingling or loss of sensation at or anywhere below your knee.

Whether you have been injured or not, call your doctor right away (day or night) if:

  • You have severe pain, swelling, redness or warmth in your knee.
  • Your knee feels swollen like a balloon.
  • You hear crunching and feel pain when you try to move your knee or to walk.

Call your doctor during regular office hours if, after an injury, you have mild to moderate pain and swelling but:

  • You have no warmth or redness around your knee.
  • You can bend and straighten your knee well.
  • You can put weight on your knee and leg without significant discomfort.

Call your doctor during regular office hours if you have not been injured but you notice that your knee occasionally buckles or gives out, or locks or something catches in the joint.

SELF-CARE AT HOME

  • You do not need to see a doctor right away for mild knee swelling and/or pain if:
    • Swelling within the joint builds up slowly and does not follow an injury.
    • Swelling and/or pain outside the knee joint gets progressively better over a week or two.
    • You have minimal discomfort on the inside or outside of your knee.
    • You have no significant bruising.
    • You have no locking, catching or buckling.
  • Once your soreness and swelling starts to get better you may try riding a stationary bike using low resistance for 10 to 20 minutes daily or every other day.
  • If your knee starts to feel normal within one to two weeks, you may attempt functional drills to see if you are ready to start sports or regular exercise again. You may progress through a series of drills by completing each one pain-free. If you have symptoms with a drill, stop and try again in a day or two.
    • Jog a straight 50-yard line at about 50-percent intensity.
    • Run a straight 50-yard line at 75-percent, then 100-percent intensity.
    • Using the same intensity progressions, run a straight line and progress through 45-degree and then 90-degree cuts to the right and to the left.
    • Then, run a large or “loose” figure-of-eight path and gradually make it smaller or “tighter” and faster with repeat attempts.

When you can do all of these drills pain-free, you can try sports-specific activity. When you return to specific sports or exercise activity, at first try sports-specific drills or exercise at only 50-percent intensity and in a noncompetitive setting. Increase intensity and participation as tolerated, being careful to avoid knee pain or other recurrent symptoms.

All other knee swelling, pain beyond two weeks, any moderate to severe pain, limitations in joint motion or symptoms such as locking or catching should be evaluated by a doctor because serious injuries can easily be missed, especially with swelling inside the knee joint

  • Avoid running, jumping, twisting and kicking until your knee has been evaluated by a doctor or until it is completely better.
  • If you have pain or a sense of buckling when you try to walk or put weight on your knee or leg, use crutches to take all the weight off your injured knee.
  • If you have pain when you try to bend your knee, hold it as straight as possible or in the most comfortable position you can find until you see your doctor.
  • Elevate your injured knee as often as you can the first few days after injury by placing it up on a couch or chair when you are sitting or lying down.
  • Place an ice pack or cold pack directly over the injured area of your knee. If you have knee pain that is not located in a specific area, put an ice pack or cold pack around your knee.
    • Use the cold pack for 20 minutes every hour or two for the first 24 to 36 hours to reduce pain, swelling and bruising.
    • After the first day or two, use cold packs at least three times daily or more often if your symptoms demand it.
    • If you are not using an elastic wrap directly over your skin, place a thin washcloth between the cold pack and your skin to minimize the risk of frostbite. The cold pack can be held in place with an elastic wrap.
    • If you are busy, you may choose to ice during meals so as to save time and avoid interrupting other activities.
  • Use a snug elastic wrap or sleeve around your knee to help minimize swelling until it improves greatly or goes away entirely.
  • Because most over-the-counter knee braces do not help stabilize your knee very well, don’t wear one without advice from your doctor.
  • You may take ibuprofen (Advil®, Motrin®) or naproxen (Aleve®) for swelling and pain. (See labels for dose and risks.)

PREVENTION

  • Regular exercise that strengthens the muscles around your knee and keeps your weight down can help prevent knee injuries.
  • A regular stretching program that focuses on the hips, legs and ankles can help prevent some knee injuries.

FOR MORE INFORMATION

REFERENCES

Last reviewed: November 2009

Last revised: November 2009