Knee meniscus tear

What Is It?

A meniscus is a disk-shaped piece of cartilage that acts as a shock absorber inside a joint. Each knee has one lateral meniscus under the outer knob of the thighbone and one medial meniscus under the inner knob of the thighbone. Each meniscus acts as a natural cushion between the thighbone (femur) and shinbone (tibia). The two cushions prevent excess wear and tear inside the knee joint by keeping the ends of the two bones from rubbing together. Each meniscus also absorbs much of the shock of jumps and landings and helps to distribute joint fluid evenly to lubricate and nourish the knee.

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CauseIn the United States, a torn meniscus is the most common reason for knee surgery.

Sudden meniscal tears often happen during sports. Players may squat and twist the knee, causing a tear. Direct contact, like a tackle, is sometimes involved.

Older people are more likely to have degenerative meniscal tears. Cartilage weakens and wears thin over time. Aged, worn tissue is more prone to tears. Just an awkward twist when getting up from a chair may be enough to cause a tear, if the menisci have weakened with age.

Symptoms

The symptoms of a torn meniscus can include:

  • Knee pain, usually on one side of your knee
  • Tenderness at the side of the joint
  • Knee swelling within the first 12 hours after injury
  • A "locked" knee that can't be bent
  • A knee that catches during movement, or can't be fully straightened
  • A click, pop or grinding inside your knee when you move it
  • A knee that buckles, gives way or feels generally weak

How is a meniscus tear classified?

A Meniscus tear can be classified in various ways – by anatomic location, by proximity to blood supply, etc. Various tear patterns and configurations have been described. These include:

  • Radial tears
    • Flap or Parrot-beak tears
    • Peripheral, longitudinal tears
    • Bucket-handle tears
    • Horizontal cleavage tears
    • Complex, degenerative tears

These tears can then further classified by their proximity to meniscus blood supply, namely whether they are located in the “red-red,” “red-white,” or “white-white” zones.

The functional importance of these classifications, however, is to ultimately determine whether a meniscus is REPAIRABLE. Given the critically important functions of the meniscus in athletes, it should be preserved and repaired whenever possible. The repairability of a meniscus is dependent upon a number of factors. These include:

  • Age
    • Activity Level
    • Tear Pattern
    • Chronicity of the tear
    • Associated Injuries (Anterior Cruciate Ligament Injury)
    • Healing Potential

- See more at: http://www.sportsmd.com/SportsMD_Articles/id/266/n/meniscus_tear___causes_symptoms_and_treatment.aspx#sthash.wbk7NvV4.dpuf

Diagnosis

Your doctor will inspect both your knees to compare your injured knee with your uninjured one. He or she will check your injured knee for signs of swelling, tenderness and fluid inside the knee joint. If your knee is not locked, the doctor will bend your injured knee and check for clicks, snaps and "catches" within the joint. Your doctor also will evaluate your knee's range of motion and will maneuver your knee to see whether your meniscus is sensitive to pressure. For example, in the "McMurray test," the doctor bends the leg at the knee, and then rotates it inward or outward while straightening it. If you feel pain during this test or if there is a "click" sound as your leg rotates, there is a good chance that your meniscus is torn.

If the results of your exam suggest you have a torn meniscus, you may need more tests, including:

  • Knee X-rays to check for bone injuries, including fracture, that can cause symptoms similar to a torn meniscus
  • A magnetic resonance imaging (MRI) scan or computed tomography (CT) scan — Nine out of 10 times, a torn meniscus will show up on one of these tests.
  • Arthroscopy (camera-guided surgery) to look inside the knee joint and examine the meniscus — When arthroscopy is used for diagnosis, the problem can often be treated during the same surgery.

What is the treatment for a meniscal tear?

When you first injure your knee the initial treatment should follow the simple PRICE method:

  • Protect from further injury.
  • Rest (crutches for the initial 24-48 hours).
  • Ice (apply ice (wrapped in a towel, for example) to the injured area for 20 minutes of each waking hour during the first 48 hours after the injury).
  • Compression (with a bandage, and use a knee brace or splint if necessary).
  • Elevation (above the level of the heart).

These actions, combined with painkillers, help to settle the initial pain and swelling. Further treatment will then depend on:

  • The size of the tear.
  • The severity of symptoms.
  • How any persisting symptoms are affecting your life.
  • Your age.
  • Your general health.

Non-operative treatment

Small tears may heal by themselves in time, usually over about six weeks. Some tears which do not heal do not cause long-term symptoms once the initial pain and swelling subside, or cause only intermittent or mild symptoms. In these cases, surgery may not be needed. You may be advised to have physiotherapy to strengthen the supporting structures of the knee, such as the quadriceps and hamstring muscles.

Surgery

If the tear causes persistent troublesome symptoms then an operation may be advised - although evidence for the benefit of some types of surgery is variable. Most operations are done by arthroscopy (see below). The types of operations which may be considered include the following:

  • The torn meniscus may be able to be repaired and stitched back into place. However, in many cases this is not possible.
  • In some cases where repair is not possible, a small portion of the meniscus may be trimmed or cut out to even up the surface.
  • Sometimes, the entire meniscus is removed.
  • Meniscal transplants have recently been introduced. The missing meniscal cartilage is replaced with donor tissue, which is screened and sterilised much in the same way as for other donor tissues such as for kidney transplants. These are more commonly performed in America than in the UK.
  • There is a new operation in which collagen meniscal implants are inserted. The implants are made from a natural substance and allow your cells to grow into it so that the missing meniscal tissue regrows. This is not yet available at all hospitals.

Arthroscopy
This is a procedure to look inside a joint by using an arthroscope. An arthroscope is like a thin telescope with a light source. It is used to light up and magnify the structures inside a joint. Two or three small (less than 1 cm) cuts are made at the front of the knee. The knee joint is filled up with fluid and the arthroscope is introduced into the knee. Probes and specially designed tiny tools and instruments can then be introduced into the knee through the other small cuts. These instruments are used to cut, trim, take samples (biopsies), grab, etc, inside the joint. Arthroscopy can be used to diagnose and also to treat meniscal tears

Prevention

Although it's hard to prevent accidental knee injuries, you may be able to reduce your risks by:

  • Warming up and stretching before participating in athletic activities
  • Exercising to strengthen the muscles around your knee
  • Avoiding sudden increases in the intensity of your training program
  • Wearing comfortable, supportive shoes that fit your feet and your sport
  • Wearing appropriate protective gear during activities, including athletic activities, in which knee injuries are common (especially if you've had knee injuries before).

Medial Meniscus Rehab

Below is an example of a rehabilitation program suitable for both conservative treatment and following surgery for a partial removal of the meniscus.1s

The following is for information purposes only. We recommend seeking professional advice before beginning rehabilitation. The cartilage meniscus rehabilitation program is split into 4 phases with a guide to when these phases should begin although timescales following injury may vary as each injury and patient will be different.

Phase 1

Duration: 0 to 1 week post injury

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The aim of the first phase is to reduce swelling, maintain the ability to straighten the knee and be able to bend the knee to just over 90 degrees.

Treatment

Ice or cold therapy can be applied for 15 minutes every couple of hours if possible to reduce swelling. Do no apply ice directly to the skin but use a wet tea towel or specialist cold therapy knee wrap which can provide both cold and compression to help reduce pain and swelling.

A compression bandage or knee support worn all the time can also help reduce swelling. In the first 24 to 48 hours when complete rest is advised a simple elastic knee sleeve is fine. Later as the athlete starts to walk then most physiotherapists will recommend a hinged knee brace or at least a strong stabilizing brace to protect the medial knee ligament and cartilage.

A physiotherapist or similar may use electrotherapy including ultrasound and tens to help disperse swelling and ease pain.

Exercises

Simple range of motion can begin within the limits of pain. Knee flexion and extension with the aim of maintaining range of motion to the injured knee. Isometric or static quadriceps exercises can begin. Double leg calf raises, hip abduction and extension and resistance band hamstring exercises can also be done on a daily basis. If pain allows use an exercise cycle to maintain aerobic fitness. Aim to walk normally with full weight bearing on the injured leg.

Phase 2

Duration: Between 1 and 2 weeks post injury5s

The aim of phase 2 is eliminate swelling on the knee and achieve full, normal range of motion in the joint.

Treatment

Continue with cold therapy applying ice 2 or 3 times a day. Wear a knee support to protect the joint and help reduce swelling. Your therapist may continue with electrotherapy with ultrasound applied around the joint to help eliminate any swelling still present.

Exercises

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Continue with flexion and extension knee range of motion exercises to regain full range of motion in the joint. Isometric quadriceps contractions can continue. Begin to do squats and lunges but only very shallow if pain allows. One quarter normal depth is sufficient to start with. Leg press machine exercises can begin with both legs initially moving onto single leg exercises.

Other exercises which can begin include step ups, hip bridges, hip abduction and extension with resistance bands, single leg calf raises and wobble balance board drills. Continue with exercise cycling if it is not painful, walking normally without a limp and if possible light swimming but only very gently with the leg kick.

Phase 3

Duration: Between 2 and 3 weeks post injury

The aim of phase 3 of a meniscus tear rehabilitation program is to ensure full range of movement in the knee, regain normal strength with the ability to perform a full squat and start to return to running and normal training.

Treatment

Treatment at this stage should be minimal. There should be no need to apply ice or wear a compression bandage for swelling. Some athletes may feel more secure wearing a stabilizing or hinged knee brace to protect the joint when exercising. Sports massage to the muscles surrounding the knee may help with rehabilitation.

Exercises

Exercises should be similar to phase 2 but increasing the number of repetitions, sets and load. Shallow squats and lunges, step ups, bridges, hip abduction, hip adduction, single leg calf raises and balance exercises should all be incorporated into the exercise plan and performed daily.

The athlete should be capable of running, swimming, road cycling and begin to perform more sports specific exercises which involve changing direction, backwards running, jumping, hopping and kicking. It is probably better at this stage to do cross train using a mix of activities to get maximum aerobic benefit without over loading the cartilage in the joint.

Phase 4

Duration: Between 3 and 5 weeks post injury

The aim of phase 4 is to ensure full strength, range of movement and muscle endurance returning to sports training and limited matchplay or competition.

Treatment

Treatment again will be minimal. There should be no requirement for cold therapy or compression. The athlete should aim to train without the use of a knee support.

Exercises

By now the athlete should be returning to normal sports specific training. Start doing part of the training session and gradually build up to completing full sports specific training sessions. When returning to match play this should be restricted to start with for example playing 20 mins of a soccer match first to see if there is any reaction afterwards or the following day before building up to full match play. Be aware that the aim is not to get back playing your first game or competition as soon as possible but the second and third.