In sports and orthopedics, a tear of a meniscus is a rupturing of one or more of the fibrocartilage strips in the knee called menisci. When doctors and patients refer to 'torn cartilage' in the knee, they actually may be referring to an injury to a meniscus at the top of one of the tibiae. Menisci can be torn during innocuous activities such as walking or squatting. They can also be torn by traumatic force encountered in sports or other forms of physical exertion. The traumatic action is most often a twisting movement at the knee while the leg is bent. In older adults, the meniscus can be damaged following prolonged 'wear and tear' called a degenerative tear.
Tears can lead to pain and/or swelling of the knee joint. Especially acute injuries (typically in younger, more active patients) can lead to displaced tears which can cause mechanical symptoms such as clicking, catching, or locking during motion of the knee joint.
The joint could be in pain when in use, but when there is no load, the pain goes away.
Symptoms
The common signs and symptoms of a torn meniscus are knee pain and swelling. These are worse when the knee bears more weight (for example, when running). Another typical complaint is joint locking, when the affected person is unable to straighten the leg fully. This can be accompanied by a clicking feeling. Sometimes, a meniscal tear also causes a sensation that the knee gives way.
A person with a torn meniscus can sometimes remember a specific activity during which the injury was sustained. A tear of the meniscus commonly follows a trauma which involves rotation of the knee while it was slightly bent. These maneuvers also exacerbate the pain after the injury; for example, getting out of a car is often reported as painful.
Main causes
There are two menisci in the knee. They sit between the thigh bone femur and the shin bone tibia. While the ends of the thigh bone and the shin bone have a thin covering of soft hyaline cartilage, the menisci are made of tough fibrocartilage and conform to the surfaces of the bones they rest on. One meniscus rests on the medial tibial plateau; this is the medial meniscus.
These menisci act to distribute body weight across the knee joint. Without the menisci, the weight of the body would be unevenly applied to the bones in the legs (the femur and tibia). This uneven weight distribution would cause the development of abnormal excessive forces leading to early damage of the knee joint. The menisci also contribute to the stability of the joint.
The menisci are nourished by small blood vessels but have a large area in the center with no direct blood supply (avascular). This presents a problem when there is an injury to the meniscus, as the avascular areas tend not to heal. Without the essential nutrients supplied by blood vessels, healing cannot take place.
The two most common causes of a meniscal tear are traumatic injury (often seen in athletes) and degenerative processes, which are the most common tear seen in all ages of patients. Meniscal tears can occur in all age groups. Traumatic tears are most common in active people aged 10–45. Traumatic tears are usually radial or vertical in the meniscus and more likely to produce a moveable fragment that can catch in the knee and therefore require surgical treatment.
Anatomy of the meniscus
The menisci are C-shaped wedges of fibrocartilage located between the tibial plateau and femoral condyles. The menisci contain 70% type I collagen. The larger semilunar medial meniscus is attached more firmly than the loosely fixed, more circular lateral meniscus. The anterior and posterior horns of both menisci are secured to the tibial plateaus. Anteriorly, the transverse ligament connects the 2 menisci; posteriorly, the meniscofemoral ligament helps stabilize the posterior horn of the lateral meniscus to the femoral condyle. The coronary ligaments connect the peripheral meniscal rim loosely to the tibia. Although the lateral collateral ligament (LCL) passes in close proximity, the lateral meniscus has no attachment to this structure.
The joint capsule attaches to the entire periphery of each meniscus but adheres more firmly to the medial meniscus. An interruption in the attachment of the joint capsule to the lateral meniscus, forming the popliteal hiatus, allows the popliteus tendon to pass through to its femoral attachment site. Contraction by the popliteus during knee flexion pulls the lateral meniscus posteriorly, avoiding entrapment within the joint space. The medial meniscus does not have a direct muscular connection. The medial meniscus may shift a few millimeters, while the less stable lateral meniscus may move at least 1 cm.
Types and classification of meniscus tears
A meniscal 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
Tear of medial meniscus
Presently, treatments make it possible for quicker recovery. If the tear is not serious, physical therapy, compression, elevation and icing the knee can heal the meniscus. More serious tears may require surgical procedures.
Conservative treatment
Initial treatment may include physical therapy, bracing, anti-inflammatory drugs, or corticosteroid injections to increase flexibility, endurance, and strength.
Exercises can strengthen the muscles around the knee, especially the quadriceps. Stronger and bigger muscles will protect the meniscus cartilage by absorbing a part of the weight. The patient may be given paracetamol or anti-inflammatory medications or biomechanical interventions such as AposTherapy For patients with non-surgical treatment, physical therapy program is designed to reduce symptoms of pain and swelling at the affected joint. This type of rehabilitation focuses on maintenance of full range of motion and functional progression without aggravating the symptoms. Physical therapists can utilize modalities such as electric stimulation, cold therapy and ultrasonography, etc.
Recently, accelerated rehabilitation programs have been used and show to be as successful as the conservative program. The program reduces the time the patient spends using crutches and allows weight bearing activities. The less conservative approach allows the patient to apply a small amount of stress and prevent range of motion losses. It is likely that a patient with a peripheral tear may pursue the accelerated program and a patient with a larger tear will use the conservative program.
Surgery
Arthroscopy is a surgical technique in which a joint is operated on using an endoscopic camera as opposed to open surgery on the joint. The meniscus can either be repaired or completely removed, this is described in further detail below. It should not be recommended for a degenerative meniscus tear, unless there is locking or catching of the knee, recurrent effusion or persistent pain. Evidence supports that it is no better than conservative management in those without osteoarthritis. Additionally there does not appear to be any benefit in those with a tear of the meniscus and mild arthritis who are adults.
If a person fails to improve after trying these treatments, then arthroscopy should be considered. Patients who additionally have osteoarthritis may require surgical options.
[...]
Risk factors and prevention
The meniscus is made of cartilage, a viscoelastic material, which makes it more susceptible to rate of loading injuries. Repetitive loading can also lead to injury. Recent studies have shown people who experience rapid rate of loading and/or repetitive loading to be the most susceptible to meniscus tears. People over the age of 60 who have working conditions in which squatting and kneeling are common are more susceptible to degenerative meniscal tears. Athletes who constantly experience a high rate of loading (i.e. soccer, rugby) are also susceptible to meniscus tears. Studies have also shown with increasing time between ACL injury and ACL reconstruction, there is an increasing chance of meniscus tears. This study showed meniscus tears occurring at a rate of 50–70% depending on how long after the ACL injury the surgery occurred.
Source: Wikipedia
Препоръчани клиники за такъв тип заболявания
