Tear of meniscus

Medical quality assurance by Dr. Albrecht Nonnenmacher, MD at July 21, 2016
StartDiseasesTear of meniscus

Similar to any serious knee injury, a tear of meniscus or torn meniscus can be both debilitating physically as well as extremely painful. This is due to the fact that the knee joint is one of the main load-bearing points in the body carrying most of the body’s weight in movement, and the meniscus is a natural cushion for that impact. When torn, the cushion fails or is gone, and bone makes contact on bone instead. Meniscus tears are quite common, being both a product of aging as well as physical exertion beyond normal, common movement. 

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Definition & Facts

The meniscus itself is a type of cartilage that takes load impact and helps the knee stay stable when in motion. The cushion aspect works as a bumper, protecting the knee and leg bones from direct contact with each other. The meniscus material itself is not as hard as bone, so under extreme pressure it can warp, tear, or rip.

This commonly occurs with a sudden twist during which the cartilage tears or shreds, unable to absorb the torsion pressure, and the bone surface gets exposed. In some cases the meniscus material tears loose and gets stuck in between the knee bones, causing the knee joint to literally jam, another painful sensation.

It does not take a heavy impact sport to cause a tear; meniscus injuries occur in all types of activity where the knee has to handle sudden changes in direction, usually with momentum and speed. These injuries also occur as the knee overcompensates for another prior injury, such as an ankle injury, and takes on more weight than normal.

Meniscus tears can also happen in conjunction with other knee injuries like sprains (torn ligaments) and pulled muscles. As people age and stay active, the risk of knee injuries go up as the cushion material wears thinner and thinner over time. Almost 1 out of 2 people older than 65 have some kind of meniscus injury.

Symptoms & Complaints

Each knee joint is designed and assembled with two menisci, one on either side. The cushion literally takes impact between the thigh bone end (femur) and the shinbone (tibia). When torn, the first symptoms will be sudden deep pain in the knee and bone end as the leg takes on a load or operates in motion.

This will likely cause an immediate limp and less use of the injured leg. Severe tears will also result in swelling around the knee joint area, bruising, and a feeling of thickness as the joint stiffens to immobilize the injury. Many patients experience pain and physical inability to straighten their knee out as well. Other symptoms include:

  • Sudden pain when moving the knee.
  • Inability to walk or run normally.
  • A resistance to fully straightening the leg at the knee joint.
  • Deep throbbing pain that worsens when sitting with the knees bent for a long time.

Causes

A torn meniscus is a tear or ripping of the cartilage material, enough that the bone beneath becomes exposed to impact as the knee is used. Sudden directional change, significantly heavy lifting with the knees and age-related knee degeneration all can contribute in part or in combination to a torn meniscus injury. In some cases the injury can occur as a previous impact, and then a sudden twist is enough to finalize the damage and tear the cartilage.

Diagnosis & Tests

An inability to move the knee at all or in a very limited capacity is the first test. In most cases a doctor will slowly bend and straighten the patient’s knee until significant pain is present. He or she will also examine the joint for swelling, stiffness and signs of bruising. The physician may ask for quite a bit of detail of activity leading up to the time of the injury to pinpoint exactly how the tear occurred. Both X-rays and MRI scans offer physicians the ability to objectively examine the knee area as well, especially to detect any loose material that may be floating around in the knee joint or bone damage.

Treatment & Therapy

In minor cases where the meniscus has only been bruised but not torn, the RICE approach (rest, ice, compression, elevation) will be recommended, along with over-the-counter painkillers. Simply keeping a load off the knee can allow it to heal on its own. Afterwards, light exercise with no or low-impact motion is often the best route for recovery (swimming or using an elliptical/bike style exercise machine).

For tears, unfortunately, surgery is often necessary to reattach the cartilage and ensure that blood is reaching the inner part of a tear. Physical therapy may be recommended and frequently involves a combination of stretching, progressive weight and strength-building, and similar low-impact exercises. The idea is to develop the leg muscles and knee ligaments so that they take on more of the load than just the knee alone. This in turn reduces the risk of new knee damage going forward.

A patient shouldn’t be running, jogging or doing any kind of jumping or landing activities during the first three months at least. Meniscus injuries, on average, can take up to six months to fully recover from. In some cases, often with the elderly, full recovery is not possible and long-term limitation can occur, and the individual may develop arthritis.

Prevention & Prophylaxis

The first big step one can take to prevent meniscus tears is to avoid exercise that exceed one's ability. Age plays a major role in increasing the risk of these types of injuries so individuals must consider their age when assessing the risk of certain exercises.

Secondly, being overweight or obese can also enhance injury risks, so losing weight if overweight or obese or maintaining a healthy weight goes a long way in terms of reducing the weight that causes damage to the knees.

Additionally, if partaking in vigorous exercise, preparation helps tremendously in avoiding injuries. Good steps involve:

  • Keeping the leg muscles warm and loose with regular activity, especially on cold days outside.
  • Performing a light, easy warmup before engaging in strenuous exercise.
  • Allowing momentary rest after a few minutes of heavy exertion.
  • Always using proper-fitting shoes for the task or activity being performed. Old shoes wear out and cause instability.
  • Stretching and staying flexible.
  • Avoiding big sudden changes in exercising. Keeping patterns constant and increasing the strenuousness of one's exercises incrementally.