Most meniscus injuries (meniscus lesions) happen during sports, due to an accident or an uncontrolled movement in which the knee is twisted too much. This often tears the meniscus, which leads to instability of the complicated knee apparatus and the lesion of the meniscus requires surgery. However, there are also degenerative changes in the menisci when cartilage mass disappears.
What are meniscus injuries?
Schematic diagram showing the anatomy and structure of the meniscus. Click to enlarge. Damage to the cartilage disc located in the knee joint represents meniscal injuries (meniscal lesions). There are two larger menisci in the knee joint area of all mammals. A great deal of weight rests on the human knee, and it is subjected to more stress than any other part of the body during the course of a human lifetime. The knee joint is a complicated structure of bone, muscle, tendons, vessels and cartilage. Two load-bearing, large cartilage ligaments of the knee are the menisci, which run around the bony kneecap. They contribute significantly to the support of the whole structure and enable the human gait and bending and stretching movements. If the cartilage of the meniscus tears due to an incorrect movement, over-rotation or a firm impact, the stability of the entire knee joint is affected. Many athletes, and especially soccer players, therefore suffer one or more meniscus tears in the course of their athletic lives. The degenerative changes of a meniscus manifest themselves as arthrosis. Meniscus injuries can therefore occur primarily as a result of force (e.g. in an accident) or cartilage wear and tear, as well as when both factors coincide. In addition, congenital malformations of the meniscus are triggers of a meniscus injury. Meniscal injuries are differentiated by the location of the lesion (posterior, medial, or anterior) and by the shape of the injury. Menisci represent a wedge-shaped as well as crescent-shaped disc of cartilage. Each of the knee joints has an outer and an inner meniscus, which are located between the head of the shin bone (tibia) and the thigh bone (femur). The meniscus ensures that these two bones, which have differently shaped surfaces, work together smoothly. The two knee joint menisci absorb about 30% of the weight loads and ensure an even distribution across the joint. Meniscal injuries compromise the stabilizing, shock-absorbing, braking, and load-distributing effects of the menisci.
Causes
Meniscal injuries, as indicated earlier, are often triggered by abrupt movements. These include sudden twisting or violent stopping, as is particularly common in some sports (e.g., soccer, tennis, or alpine skiing). The combination of high pressure and twisting motion not infrequently causes both ligament and meniscus tears. Movement sequences performed regularly over longer periods of time (e.g., long-distance running) also place stress on the cartilage and can cause meniscus injuries. Since menisci renew themselves only to a limited extent, they lose some of their efficiency with increasing age. Over the years, they begin to become brittle and develop cracks, so that even moderate stresses on a meniscus can lead to a tear. There is also the possibility that malpositions of the legs can trigger meniscus injuries (meniscus lesions). “Bow legs” are more likely to cause injuries to the medial meniscus, while “knock knees” are more likely to put the lateral meniscus at risk.
Symptoms, complaints, and signs
Meniscal injuries (especially meniscal tear) are noticeable by a typical pain characteristic, which in most cases occurs in relation to certain movements. Pain conditions vary depending on whether the inner or outer meniscus is involved. The outer meniscus hurts most when the knee is rotated inward or when the patient squats, i.e., puts the knee joint into a severe flexion. Injury to the medial meniscus also causes the knee to hurt when the patient is in a bent position, but in addition, it often hurts when the patient straightens up from a squat position. In addition, with meniscal injuries to the inside of the knee, external rotation of the knee is associated with pain. Both meniscus injuries are felt with a sharp, bright pain during the aforementioned movements. In addition, there is a pressure pain.when patient or doctor at the gap of the knee joint where upper and lower leg meet. This gap can be felt by the layperson with a little practice. When the outer meniscus is injured, the pressure pain is felt at the lateral knee joint gap, and when the inner meniscus is damaged, it is felt at the medial knee joint gap. Problems with walking in conjunction with stabbing knee pain also indicate meniscus injuries. In particular, this is the case if there was a previous fall or confrontation during sports. A palpable effusion may indicate inflammation.
Diagnosis and progression
The patient usually notices immediately on his or her own that the meniscus is torn or ruptured. Affected patients report that the tearing of the meniscus was literally heard through a bang. The physician can often detect a meniscus tear just by a physical examination. The kneecap has slipped or is at least very easy to move and no longer has any support. The diagnosis is confirmed by arthroscopy, in which a probe with a small miniature camera is inserted into the knee area. Now the doctor can see the tear or even several tears in the cartilage of the meniscus. If an arthroscopy device is not immediately available, an ultrasound examination can also be used for the initial diagnosis. More detailed examinations must follow as soon as possible in the hospital or in an orthopedic practice. The basis for a diagnosis of meniscus injuries is not only the acute symptoms, but also the patient’s information about continuous stress and accidents in the past. With a few simple steps and examinations, the physician can usually diagnose both meniscus damage and possible other knee joint injuries. If an effusion has formed in the knee joint, fluid can be removed by puncturing the joint and analyzed to support the diagnosis. An x-ray will provide information about any bone injuries and cartilage wear. If there is still doubt then, as already noted, arthroscopy (knee arthroscopy) or magnetic resonance imaging (MRI) usually leads to a clear diagnosis. If meniscal damage is not treated in a timely manner, joint effusions can expand and more extensive cartilage damage can occur, resulting in osteoarthritis. Incurred tears can expand and even cause the meniscus to tear. If the meniscal damage is in an area of cartilage with adequate blood supply, meniscal lesions have a good chance of healing. For some people, a meniscus tear is almost painless, while others complain of pain in the knee area. Normal walking is no longer possible after a meniscus tear and the patient must undergo surgery. Meniscus tear is usually not treated as an emergency, but surgery is also not waited longer than absolutely necessary, otherwise the cartilage could suffer further damage from stress. Until surgery is performed, the knee is supported by a brace; plastering the knee, which was used in the past, is now controversial both before and after surgery.
Complications
Depending on the severity of the meniscal injury, the injury is treated either surgically or locally in milder cases. If surgery eventually occurs due to a severe injury, it is associated with certain risks, as are all other surgeries. One possible complication – especially with the open surgical method – is secondary bleeding. Another risk is infection caused by certain germs in the wound. An infection in the knee joint represents a very unfavorable disturbance in connection with a meniscus injury, since the inflammation can cause severe damage to the knee joint cartilage. However, infection after meniscus surgery rarely occurs because the surgical procedure is always performed under sterile conditions. In some cases, pain may persist after meniscus surgery or reappear after a period of time. If replacement of the meniscus occurs, there is a risk that the implant will also tear. Another complication after meniscus replacement is an effusion in the knee. This would make puncturing the knee a necessity. These after-effects can occur, but in reality they are very rare. In general, after meniscus surgery, one should always be aware of the risk that the meniscus could tear again later.
When should you go to the doctor?
If the individual experiences sudden musculoskeletal discomfort, there is a health impairment that needs to be investigated and treated. If mobility is restricted, medical care is needed. If there is pain in a resting position, a sensation of pain when the knee is touched or when pressure is applied to the knee, and during locomotion, a physician should be consulted. Characteristic of a meniscus injury is pain while the affected person is sitting up from a squatting position or is in a flexed posture. A loss of usual physical performance as well as disturbances in usual movements are signs of a present disorder. A doctor should be consulted if there is no improvement in the symptoms. If swelling occurs on the knee, there is discoloration of the skin or the knee becomes warm, a doctor should be consulted. If the symptoms start immediately after a sudden movement, an accident or during the performance of sports activities, a visit to the doctor is advisable. If an effusion can be felt at the knee joint or if the visual shape of the knee has changed, a doctor is needed. If inward rotation of the knee is associated with discomfort, a doctor’s visit should be made. In the case of a meniscus injury, cooling the knee joint is found to be comfortable and relieves pain. It should be performed until the examination.
Treatment and therapy
The actual surgery for the meniscus lesion is performed either under partial or general anesthesia. This involves ligating the knee and making a small incision near the area to be operated on. Large surgical incisions are no longer necessary with today’s invasive technology. Using arthroscopic surgical equipment, the surgeon removes scattered cartilage, reassembles and sutures the torn portions of the meniscus. In some patients, the meniscus is torn into two, three or even more pieces. The wound is then sutured and the leg is bandaged. So a patient operated on the meniscus needs a lot of patience to make the knee efficient again. Physiotherapy of the operated knee is usually started a few days after the operation. If the movement of the knee is not trained, it is in danger of stiffening. It is therefore essential that the patient keeps the appointments with the physiotherapist or the orthopedist. Physiotherapy hurts and the treatment can take months, or even years in older people. In the first weeks and months after the operation, the doctor will again perform arthroscopies to observe the healing process. During this time, he will also remove wound water by puncture, which can always accumulate in the knee. There is no guarantee that the meniscus will not tear again. Supporting the actual operation and also in case of arthrosis, cartilage reconstruction by injections with hyaluronic acid can be attempted in the follow-up treatment. The goal of treatment for meniscus injuries is, on the one hand, to achieve freedom from pain or at least pain relief and, on the other hand, to restore the functionality of the joint. Conservative therapy without surgery, but possibly also surgery can be considered. If there are only minor injuries to the meniscus, conservative treatment with medication and exercise therapy is used. However, surgery is often required, but efforts are made to preserve as much of the cartilage as possible. Before starting conservative therapy, the patient is informed about the natural course of the disease. The doctor also gives advice on everyday behavior that is easy on the knee joints. In the future, for example, patients should avoid sports that require too many abrupt changes in movement. The patient should also avoid squatting too deeply. Specially designed physiotherapy is used to strengthen the muscles of the thighs in particular. Electrotherapy can also be used as a supplement. Crutches relieve the knee joints of the convalescent to a large extent. If inflammation is also present, cooling has a pain-relieving effect. For painful inflammation, cortisone-free drugs are preferably administered. As already mentioned above, operations are nowadays performed by means of knee arthroscopy under general or partial anesthesia. Depending on the extent of the damage, operations are performed on an outpatient or inpatient basis, with hospital stays of only one week usually being required.Open surgery, rather than arthroscopic surgery, is usually required only when ligament and bone damage are present in addition to meniscal injuries (meniscal lesions).
Outlook and prognosis
A prognosis depends primarily on the extent of the damage. Age and general health also play a role in the prospects for recovery. The worst course is no treatment. In most cases, this makes the meniscus injury worse. It also damages other areas of the knee, such as the ligaments. Meniscus injury is considered a man’s disease. About twice as many male patients as women show up in doctors’ offices. Athletes and employees in physically demanding occupations are considered the main risk group. Minor damage can usually be treated successfully with conservative methods. After a good two weeks of rest, gradual exertion can be resumed. More severe damage requires surgical treatment. The chances of success here are considered good. Complications play only a minor role. Gradual weight-bearing is possible again after about eight weeks. Statistically, there is an increased risk of re-injury after a single injury. Before resuming physically intensive activities, the treating physician should be consulted. Depending on the outcome of the therapy, patients may have to accept restrictions. Certain sports may no longer be practiced, and career reorientation may be indicated.
Prevention
Avoiding deep squats as much as possible helps prevent meniscus injuries. Sports that place particularly high stress on the knee joints (such as skiing, handball, soccer, and tennis) should rather be avoided. In any case, a sufficient warm-up phase should take place before the sport and the wearing of protectors should not be dispensed with. Alternative sports such as swimming or cycling as well as gymnastics ensure the mobility of the knee joints in the long term and are therefore a good prophylaxis against meniscus lesions.
Aftercare
In most cases, meniscus injuries are associated with severe pain, which has a very negative impact on the quality of life of the affected person and also reduces it significantly. The affected person should slowly resume the usual rhythm to avoid further discomfort. Sporting activities should be avoided until the attending physician no longer sees any cause for concern. Sometimes affected persons are dependent on the help and support of friends or relatives to cope with everyday life. Sufficient rest and a positive attitude promote a rapid recovery.
What you can do yourself
In the case of a meniscus injury, it is necessary to seek the assistance of a physician. Despite your best efforts, the injury cannot heal completely without symptoms without medical care on your own. In addition, there are some options that the affected person can apply for the improvement of his well-being and faster relief of discomfort. The protection of the knee is particularly important. Loading of the joint should be done carefully and only according to the individual possibilities. If too much strain is placed on the knee, the complaints will increase. Physiotherapeutic exercises help to achieve a healthy and optimal range of motion. These can be performed daily and independently. To cope with everyday life, it is advisable to restructure some routines and enlist the help of relatives or friends. Wearing healthy footwear is also beneficial. High heels should be avoided. Comfortable, closed-toe and breathable shoes in the right size help to prevent incorrect stress or deformity. Sports should be discontinued until the end of the healing process. Sports that put a lot of strain on the knee should also be avoided or reduced afterwards. Sports that are easier on the joints are more helpful. These include swimming or walking.
