Meniscus (knee) tears Symptoms & Causes

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If your child or teen has sustained a meniscus tear, it will comfort you to know that Children’s Hospital Boston’s Orthopedic Center has a tremendous amount of experience treating this injury, developing therapies for healing and conducting research that leads to better care.

How do meniscus tears occur?

Football players and others in contact sports can tear a meniscus when twisting the knee, pivoting, cutting or decelerating. In athletes, meniscus tears often happen in combination with other injuries such as a torn ACL (anterior cruciate ligament).

Are there different kinds of meniscal tears?

In young athletes, the meniscus can tear in a number of different ways: 

  • Young athletes often get longitudinal or “bucket handle” tears if the femur and tibia trap the meniscus when the knee turns.
  • Less often, young athletes get a combination of tears called radial or “parrot beak,” in which the meniscus splits in two directions due to repetitive stress activities, such as running.
Common types of tears

[illustration courtesy of the American Academy of Orthopaedic Surgeons]

What should I do if I think my child has torn his meniscus?

If you think your child has a meniscal tear, see his doctor right away for diagnosis and treatment. Without treatment, a loosened fragment of the meniscus may drift into the knee joint, causing it to slip, pop or lock; if this happens, the knee can get stuck, often at a 45-degree angle, until it’s moved manually or otherwise manipulated.

How are meniscal tears diagnosed?

Your child’s doctor can usually diagnose an injury to the meniscus based on a physical exam of the knee (see McMurray Test in Tests). The orthopedic surgeon may also require further diagnostic studies, including:

  • MRI (magnetic resonance imaging): a diagnostic procedure that uses a combination of large magnets, radiofrequencies and a computer to produce detailed images of organs and structures within the body
  • arthroscopy: a minimally invasive outpatient procedure that inserts a small camera into the joint for the doctor to inspect

How is a meniscus tear treated?

Initial treatment follows the basic “R.I.C.E.” formula: rest, ice, compression and elevation, combined with non-steroidal anti-inflammatory medications for pain. If the knee is stable and doesn’t lock, this conservative treatment may be all that’s needed. Blood vessels feed the outer edges of the meniscus, giving that part the potential to heal on its own. So, small tears on the outer edges often heal themselves with rest.

Additional measures to support this conservative approach to treatment can be:

  • crutches to take pressure off the knee
  • exercises to strengthen and stabilize the muscles around the knee
  • arch supports or other shoe inserts to redistribute weight while walking

If the tear doesn’t heal on its own, surgery or other techniques may be needed.

Why are there more meniscal tears and overuse injuries in kids these days?

Youth and adolescent participation in organized sports has grown to about 35 to 40 million kids across the United States. Not surprisingly, the incidence of sports injuries is rising—statistics suggest that 30 to 60 percent of student athletes will have an overuse injury at some point in time. In one Sports Medicine practice at Children’s, for example, at least half of the young patients have an overuse injury.

Aren’t organized sports supposed to be good for kids?

Organized sports are very important and help kids—not just in the sports themselves, but in academics and social situations—and they’re good for children’s overall development and growth. The downside is that “overuse syndrome,” where the kids repeat the same drill over and over, causes overuse injuries.

How can parents and coaches help kids avoid meniscal tears and overuse injuries?

Parents and coaches have a great deal of influence—for better or for worse. They should stress moderation in training and should restrain the zeal with which they push youth and teens.

Coaches themselves should learn and use proper training techniques and should avoid too many repetitive drills, since these are the overwhelming reason for overuse injuries. Coaches should also teach proper running mechanics and other sports-motion techniques.

Physical education departments should make sure that the surfaces of a track or field are in good shape, and that proper equipment, footwear and protective gear are used for each sport.

Our orthopedic specialists advise:

  • warming up and stretching before practice
  • resting at least one day a week
  • cross-training/alternating sports: It is usually unwise for a child or teen to specialize in just one sport. Multi-sport athletes tend to get fewer overuse injuries than those who specialize in just one sport.
  • alternating exercises during practice: An athlete less likely to experience an injury—and  over the long term, his muscle memory actually improves—if one varies practice drills.

Can a meniscal tear be prevented?

A torn meniscus is not strictly a preventable injury, since sports such as basketball, soccer, skiing, gymnastics, volleyball and football do put athletes at some risk to tear a meniscus. But athletes and active young people can reduce their risk by:

  • maintaining general health and fitness: sport-specific conditioning, diet, exercise, sleep
  • learning/using proper sport-specific movements (form) and techniques
  • wearing/using proper sport-specific gear (see next question)
  • risk awareness: learning which moves cause risks
  • hamstring/leg strengthening (especially for girls)

Are there other guidelines and resources for injury prevention and safer training?

The American Academy of Orthopaedic Surgeons (AAOS) has issued comprehensive guidelines for helping to prevent sports injuries. Below is an excerpt from the AAOS recommendations:

  • Use proper equipment.
    • Replace athletic shoes as they wear out.
    • Wear loose-fitting clothes that are light enough to release body heat.
    • In cold weather, dress in removable layers.
  • Warm up.
    • Warm up to prepare to exercise, even before stretching.
    • Run in place for a few minutes.
    • Breathe slowly and deeply, or gently rehearse the motions of the exercise to follow.
  • Stretch.
    • Stretch slowly to the point of muscle tension.
    • Hold each stretch for 10 to 20 seconds, then slowly release.
    • Inhale before each stretch, exhale on release.
    • Do each stretch only once.
    • Never bounce on a fully stretched muscle.
  • Drink water.
    • Drink enough water to prevent dehydration, heat exhaustion and heat stroke.
    • Drink 16 ounces (one pint) of water 15 minutes before exercising, another 16 ounces after cool-down.
    • Drink water every 20 minutes or so while exercising.
  • Cool down.
    • Cool down for twice as long as warm-up.
    • Slow down motion and lessen intensity for at least 10 minutes before stopping completely.
  • Rest.
    • Schedule regular days off from exercise, and rest when tired.
    • Fatigue, soreness and pain are good reasons to not exercise.

Will my child be OK?

The good news is that 98 percent of patients with simple meniscus tears are able to return to sports and regular activities without knee instability.

After your child’s knee has healed, and after his strength and stability have returned through physical therapy, he should be able to return to his previous sports and activities—usually within six months. (But his doctor may recommend lifestyle changes for him if he has joint changes, such as arthritis or instability, which couldn’t be corrected even with surgery.)

Your child’s rehab team will help him relearn normal movements and pain-free activities. After he has successfully eliminated most of his discomfort and has returned to his normal routine, it’s important for him to continue to be involved in some form of orthopedic fitness to ensure continued physical health and well-being.

What is the Orthopedic Center doing to encourage injury prevention and safer training?

With Children’s goal of dramatically reducing overuse injuries in youth sports, members of our team often travel to local and regional schools, youth groups and sports clubs to teach leg strengthening and other techniques. We also conduct frequent safe training programs and clinics for coaches. Call 617-355-3501 for details.


As more and more kids play organized sports, there’s been a rise in the number of meniscal tears and other overuse injuries (microtraumas to bones, tendons, ligaments or muscles) among adolescents and children, largely from repetitively using the same parts of the body. Football, tennis and basketball players can tear a meniscus by twisting the knee, pivoting, cutting or decelerating. Meniscus tears often happen in combination with other injuries, especially a torn ACL (anterior cruciate ligament).

Signs and symptoms

  • a “popping” sensation in the knee
  • stiffness and swelling
  • pain when twisting or rotating the knee
  • difficulty in fully straightening the knee, or feeling like the knee is locking
  • tenderness in the joint line
  • collection of fluid (“water on the knee”)

When to seek medical advice

Meniscus tears usually cause enough discomfort that an injured child will seek medical or parental help. Consult your child’s doctor if:

  • your child is in pain
  • his knee is swollen
  • walking and bending his knee are difficult

Who’s at risk

At greater risk than some young athletes are those whose sports involve quick pivoting, cutting, decelerating and side-to-side motions, such as football, tennis, skiing and basketball.


Complications after proper treatment for meniscal tears are rare, but can occur if surgical repair has been needed. Complications can include:

  • bleeding or infection (1 percent)
  • nerve or vessel injury
  • retear of the meniscus (5 to 25 percent)
  • knee stiffness (5 to 25 percent)
  • premature arthritis
  • need for further procedures

Extremely rarely, there can be acute injury to the popliteal artery (0.01 percent), weakness or paralysis of the leg or foot, or a blood clot in the calf veins (0.12 percent).


For teens


Many teens who have a meniscal tear are not only high-performing, determined athletes, but also high-performing, determined students. If you approach your healing period with that same spirit of determination, you should be back to sports and your active lifestyle within a few months, depending on how severe your tear was in the first place.

The most important thing you can do to get back into your sport is to give your knee a total rest. But even though you know the importance of rest to your recovery, you may still find this to be a tough time. If you feel frustrated, depressed or angry during this important time, speak to your doctor, parent or counselor—they’re all on your team, and they all want to help.


For parents


If your teen is like many young athletes who’ve sustained a meniscal tear, he’s not only a high-performing, determined athlete—he’s also a high-performing, determined student. Encourage him to approach his recovery period with the same spirit of determination that he applies to other areas of his life. With patience and perseverance, he’ll probably be back to sports and his active lifestyle within a few months.

Even though you and your teen know the importance of resting his knee, you both might experience his healing period as a difficult time. Parents who identify with their children’s success can feel frustrated or depressed along with their children, so speak to your doctor or counselor if you need help.



Our Sports Medicine specialists advise young athletes to:

  • warm up and stretch before practice
  • rest at least one day a week
  • cross-train/alternate sports: It’s usually unwise for a child or teen to specialize in just one sport. Multi-sport athletes tend to get fewer overuse injuries than those who specialize in just one sport.
  • alternate exercises during practice: An athlete less likely to experience an injury—and  over the long term, his muscle memory actually improves—if one varies practice drills.

Long-term outlook after surgery

If your child needed surgery, his long-term outlook is excellent. Most patients who’ve had surgery for meniscus tears can return to sports and regular activities without knee instability. Some patients do complain of stiffness and pain after surgery, but current surgical and physical therapy techniques have minimized these problems.

Meniscus tears glossary


  • ACL (anterior cruciate ligament): a major ligament in the knee that connects the tibia to the femur at the center of the knee; helps stabilize the knee,limiting rotation and forward motion of the tibia; often becomes injured in association with a meniscal tear
  • arthroscope: a thin, fiberoptic scope introduced into a joint for diagnostic and treatment procedures inside the joint; used in ACL diagnosis and repair
  • brace or cast: a custom-made protection worn around your child’s knee while it heals
    after surgery for a meniscus tear
  • cartilage: a smooth, rubbery tissue that cushions the bones at the knee joint, and allows the knee to move easily without pain
  • The Center for Families at Children’s: dedicated to helping families find the information, services and resources they need to understand their child’s medical condition and take part in their care
  • diagnosis, diagnostics: identifying disease or injury through examination, testing and observation
  • femur: thigh bone
  • knee: the largest and most complex joint in your child’s body, joining the thigh bone and shin bone and covered by the patella. It depends on four ligaments, as well as other muscles and tendons, to function properly. Menisci on both sides of the knee help cushion the knee and keep the femur and tibia from grinding against each other.
  • lateral: side
  • laxity (in the knee): looseness, instability
  • ligament: elastic band of tissue connecting bone to bone
  • medial: inside
  • meniscus (lateral meniscus, medial meniscus): a pad of cartilage that contains thick bundles of collagen fibers and cushions the knee joint. Menisci can be found on both the lateral (outside) and medial (middle, inside) sides of the knee.
  • meniscal tear: an injury to the meniscus; often treated with rest, but occasionally needing surgical repair
  • meniscal repair: procedure undertaken if the meniscus has been torn, often at the same time as ACL surgery
  • microtrauma: a small injury to the body, such as microtears to muscle fibers, stress to the tendon, bruising of the bone; can occur to bone, muscle, tendon or ligament. If not allowed rest in order to heal, microtraumas can lead to overuse injuries, such as meniscus tears.
  • MRI (magnetic resonance imaging): produces detailed images of organs and structures within the body; shows the amount of damage to the meniscus, ACL and any other parts of the knee, such as cartilage and/or other ligaments
  • non-surgical (non-operative) treatments: alternatives to surgery; most treatments for overuse injury are non-surgical
  • orthopedics: the medical specialty concerned with diagnosing, treating, rehabilitating and preventing disorders and injuries to the spine, skeletal system and associated muscles, joints and ligaments
  • orthopedist/orthopedic surgeon: a physician concerned with diagnosing, treating, rehabilitating and preventing disorders and injuries to the spine, skeletal system and associated muscles, joints and ligaments
  • overuse injuries: sports-related microtraumas that result from repetitively using the same parts of the body, usually by overtraining; can occur to muscle, tendon, ligament or bone
  • physical therapy: a rehabilitative health specialty that uses therapeutic exercises and equipment to help patients improve or regain muscle strength, mobility and other physical capabilities
  • post-operative (post-op): occurring after surgery
  • premature arthritis: inflammation of a child’s (knee) joint caused by trauma to the joint, as in a meniscal or ACL tear; often accompanied by pain and swelling
  • pre-operative (pre-op): occurring before surgery
  • tibia: shin bone


Boston Children's Orthopedic Care in Lots of Places

Boston Children's physicians provide orthopedic care at Boston Children's locations in Lexington, Peabody, Weymouth and Waltham, as well as at our main campus in Boston.

We are grateful to have been ranked #1 on U.S. News & World Report's list of the best children's hospitals in the nation for the third year in a row, an honor we could not have achieved without the patients and families who inspire us to do our very best for them. Thanks to you, Boston Children's is a place where we can write the greatest children's stories ever told.”
- Sandra L. Fenwick, President and CEO

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