Knee injuries are quite common in the United States and around the world. Indeed, the knee’s numerous, interconnected components make it a complex structure that is vulnerable to many different types of injury. A substantial proportion are sports-related and involve people younger than 25; in fact, 40-50% of all sports injuries occur in the knee. According to the American Academy of Orthopaedic Surgeons, one of the most common knee injuries is a torn meniscus.
How Does the Knee Work?
Before you can understand a torn meniscus, it’s helpful to have an overview of how the knee is constructed and how it functions. The knee is the largest joint in the body and the meeting point of the thighbone (femur), shinbone (tibia), and kneecap (patella). The ends of each of these bones are covered in a soft, elastic-like tissue called cartilage; this material serves to protect the bones from friction as the knee bends.
The knee joint is held together by a two-layered envelope called a joint capsule. The inner layer of the joint capsule is filled with fluid that keeps the joint lubricated, and the outer layer is made up of connective tissue that connects it to the ligaments and tendons attached to the leg bones and leg muscles. Whenever the knee bends, the patella moves smoothly across the femur, propelled by muscles and tendons and protected by cartilage and joint fluid.
What is the Meniscus?
In addition to the articular cartilage that covers the ends of the knee bones, there is also a crescent-shaped piece of cartilage called the meniscus. Though the term is often used singularly, there are actually two different parts of the meniscus: lateral meniscus (away from the midline of the body) and medial meniscus (toward the midline of the body). Because the two halves of the meniscus are located between the femur and tibia, they provide overall stability as well as acting as shock absorbers for vertical impacts to the two bones.
How Can the Meniscus Tear?
Meniscal tears generally happen as a result of some kind of trauma. As noted above, many instances of trauma occur while participating in sports. Though meniscal tears are a common type of injury in contact sports, it isn’t necessarily the contact (or impact) that causes the tear. Any kind of sharp movement that results in a twisting motion in the knee can potentially cause a tear. A position that is especially vulnerable is twisting the knee while the leg is in a bent position.
In addition to acting as shock absorbers, the menisci distribute weight across the knee joint and thereby protect it from potential damage. Small blood vessels feed the menisci around the outside, but the area in the center is avascular and thus has no direct blood supply. When an injury to the meniscus occurs, then, the lack of a direct blood supply means that healing is slow because vital nutrients can’t get to the site of the injury and help it heal properly. Sometimes a traumatic injury can tear the meniscus as well the anterior cruciate ligament (ACL), the fibrous tissue that partially connects the femur to the tibia.
Being tackled in a football game or making a sudden pivot on a tennis court are common ways you might get a torn meniscus, but you don’t have to be an athlete to injure your knee. As people get older, cartilage in the knee tends to degrade and become weaker. It is for this reason that elderly people can tear their meniscus after merely getting up from a chair awkwardly or twisting a leg while climbing stairs. In people with osteoarthritis, a meniscal tear can happen just because of advanced degeneration of cartilage and not even from a specific knee injury.
Symptoms of a Torn Meniscus
One of the most commonly reported symptoms of a torn meniscus is a feeling that something has “popped” inside the knee at the time of the trauma. Knee pain typically follows, especially along the line of the joint. Symptoms can also include stiffness, swelling, or an inability to fully bend or straighten the leg. Some people also have a feeling that the knee may give out. Most of the symptoms are more pronounced when more weight is put on the knee or when moved in a similar way as when the trauma happened.
Treatment Options for a Torn Meniscus
Though the avascular nature of the meniscus’ center can make for a slow healing process, it is still possible for a tear to heal on its own. How long it takes to heal, and the level of treatment that might be needed, are dependent on the size and location of the tear. In the outer edges, where the blood supply is ample, a small tear will likely heal on its own; if the tear is closer to the center, though, treatment from a doctor may be necessary. Below are some basic treatment tips for how to care for your knee in the days following the injury:
- Rest: Put as little weight on the leg in question as possible, and get plenty of rest.
- Ice: Place an icepack on the knee for 20 minutes, a few times a day.
- Compression: Wrapping your knee in a compression bandage can help keep swelling down.
- Elevation: When resting, keep your knee elevated above the level of your heart in order to reduce swelling.
- Medication: Over-the-counter non-steroidal anti-inflammatory drugs (NSAIDs) like ibuprofen can help with swelling and knee pain.
- Physical Therapy: As a tear is healing, physical therapy assists in building up other surrounding muscles through strengthening exercises.
If the tear is more serious and not likely to heal on its own, a doctor may order an X-ray or magnetic resonance imaging (MRI) to determine the extent of the damage. In such cases arthroscopic surgery may be required for meniscus repair. An orthopedic surgeon will use an arthroscope to make the repair through a small incision in the knee. If a surgical repair can’t be made, the surgeon may have to perform a full or partial meniscectomy; in some cases meniscal implants or transplants can also be an option.
Get Your Knee Checked Out at TrustCare
Meniscus injuries can be scary, especially for young athletes who are eager to compete. If you have knee pain or have experienced any of the other symptoms noted above, you may have a torn meniscus. At TrustCare, we are passionate about getting you great health care as quickly as possible. Visit one of our urgent care facilities for rapid relief on a walk-in basis or contact us for more information.