A Baker’s cyst is a type of bulge that is located in the back of the knee and is filled with fluid. It is often the result of chronic internal diseases of the knee joint.
What is a Baker cyst?
The Baker cyst owes its name to the English surgeon W. M. Baker, who first described the Baker cyst in the 19th century. From the outside, the Baker cyst looks like a tumor in the popliteal area; this must be ruled out as soon as possible. The starting points of Baker’s cyst are either directly at the posterior joint capsule of the knee, at the calf muscle musculus gastrocnemius or at the flexor muscle musculus semimembranosus, which runs on the back of the thigh to the knee. Predominantly, however, the joint capsule is the site where the cyst forms. When a rupture of the cyst occurs, the fluid leaks into the surrounding tissue and pain in the area increases. A Baker cyst usually occurs in middle to advanced age.
Causes
So-called internal diseases of the knee joint are the cause of a Baker cyst, in which the body produces more joint fluid. As a result, there is a steady increase in pressure in the joint and a bulge can form on the joint capsule, the Baker cyst. This fluid-filled capsule is easily felt in the back of the knee and resembles a blister on the foot when light pressure is applied. However, other conditions at the joint can also promote the formation of a Baker’s cyst, such as chronic polyarthritis or long-standing meniscus complaints.
Symptoms, complaints and signs
Baker’s cyst first becomes noticeable through a pressure pain on the back of the affected knee. The pain, which is initially still diffuse, often occurs during heavier exertion, such as during sports or long walks. As the cyst develops, the pain becomes more noticeable. Soon the cyst is palpable even on self-examination. The surrounding tissue is also swollen and may be red. The cyst is formed inside the knee by an accumulation of knee joint fluid that cannot be removed by the body on its own. A capsule forms around the accumulation of fluid. This system fills up more and more over time and causes an unpleasant to severe pressure pain under load. As the disease progresses and the cyst continues to grow, the mobility of the knee becomes more and more restricted. Severe discomfort occurs when walking. Especially climbing stairs in both directions can become very painful. In the immobile resting state of the locomotor system, on the other hand, the cyst does not cause any independent pain. The problem of Baker’s cyst is often aggravated by the patient’s pain-induced poor posture and relieving posture. Since the musculoskeletal system is often loaded predominantly on one side on the side that is not diseased, overloading occurs at other joints, which can lead to further inflammation or painful tension.
Diagnosis and course
Baker’s cyst is diagnosed based on the symptoms present and a physical examination. This is because even pressing on the back of the knee causes severe pain in the patient. If a physical examination is not sufficient to be able to determine the Baker cyst with certainty, an X-ray image is also taken. Because then it can be differentiated: is it really a Baker’s cyst or a knee joint arthrosis, or even a tumor, which triggers the complaints. An ultrasound examination can also show exactly how large the cyst is and how far it has already spread. If the cyst has a tubular shape or if there are already cracks or bleeding, the diagnosis can be complicated. Often, the symptoms may improve on their own as the cyst progresses. A Baker cyst may disappear spontaneously, but may reappear due to stress.
Complications
If the Baker cyst has lodged in the knee joint, immediate action must be taken because the condition may worsen acutely. The increased production and accumulation of synovial fluid in the knee joint capsule can damage it over time. A number of complications follow, which cause the patient unpleasant pain.The cyst does not only occur in older people, athletes and workers who are exposed to a high knee load also belong to the risk group. At times, bacteria, rheumatoid disease, an accident or knee surgery can be triggers for a change in the viscous synovium. Once blood is mixed with the fluid, the cartilage can be aggressively damaged. Immobilization of the leg in combination with anti-inflammatories or cortisone helps prevent complications. If the cyst cannot be reduced by conservative methods, surgical intervention is the best way to get rid of this problem in the long term. If the swelling is ignored, the Baker cyst always forms anew. If synovial fluid accumulates increasingly, the surrounding healthy tissue is compressed. Numbness and paralysis, occur and extend to the foot. Pain intensifies, the cyst ruptures and its fluid spreads to the lower leg muscles. Symptoms of lower leg thrombosis occur.
When should you go to the doctor?
A Baker cyst does not require immediate medical attention. However, if severe symptoms develop, a visit to the doctor is recommended. For example, if the cyst presses on the nerve pathways, this can cause unpleasant sensory disturbances. Similarly, severe knee pain, paraesthesia in the lower leg and feet, and persistent ankle pain may occur. If any of these symptoms persist longer than usual, a physician must clarify the condition and, if necessary, initiate treatment directly. As a general rule, as soon as a Baker cyst significantly limits quality of life, it should be treated medically. An emergency physician should be called if the cyst slips or bursts open – for example, as a result of rupture or inflammation of the surrounding tissue. If left untreated, it can lead to fluid stasis and subsequently even to loss of the lower leg. For this reason, first aid measures must sometimes be applied. The affected person should keep his legs elevated and carefully bandage the Baker’s cyst until the emergency services arrive. Even the suspicion that a cyst could open should lead to the doctor.
Treatment and therapy
Baker’s cyst can be treated both conservatively and surgically. Both methods aim to completely eliminate the swelling that has occurred in the back of the knee and the pain associated with it. In the case of a Baker cyst in childhood, conservative therapy is usually sufficient to achieve complete freedom from symptoms. If there is no improvement, surgical therapy is advisable, but also if the cause is meniscus damage, for example, and these complaints should also be alleviated. This also prevents the formation of a new Baker cyst. Conservative therapy focuses primarily on treatment with drugs that have an anti-inflammatory effect. Cortisone is also used, even if its use is controversial (due to side effects). Here, a cortisone preparation is injected into the knee joint so that the inflammation is stopped locally. If after half a year there is still no regression of the cyst, the Baker cyst is usually removed surgically. Care must be taken to interrupt the pedicle that connects the joint and the cyst.
Outlook and prognosis
The prognosis for a Baker cyst is very favorable. The cyst can usually be completely removed by a physician with a few simple steps. Wound care should be sterile so that no sequelae develop. The patient can be discharged from the treatment within a short time without any symptoms. Depending on the location and size of the cyst, surgical intervention may be necessary in some cases. This is a routine procedure that also takes comparatively little time. The patient is discharged home the same day after the procedure. A few days of rest should be given to the patient until he is symptom-free even then. Very rarely there is contamination of the wound. This leads to a delay in the healing process. If renewed medical treatment is not sought, germs or pathogens can enter the organism and cause further illness. In severe cases, the patient is threatened with blood poisoning, which can have a fatal course.The Baker cyst may have caused movement restrictions of the knee due to its location. In order not to jeopardize the healing process, the patient should not overexert himself and should keep the knee sufficiently still. The mobility of the knee starts immediately during recovery and is present as usual afterwards.
Prevention
Only certain causes of Baker’s cyst can be prevented. For example, if the meniscus is already in discomfort, it is possible to avoid stressful sports or even not to perform certain movements, as is the case with tennis or soccer. Sports that are easy on the knee, such as cycling or swimming, should then be performed. Those who enjoy jogging in the fresh air can try walking as an alternative. Those who work in the office should change sitting positions frequently so that the knee joint is not always in the same position.
This is what you can do yourself
Swelling in the back of the knee should be observed. The cause may be damage to the knee joint that needs to be treated. For mild or moderate pain, over-the-counter pain relievers such as ibuprofen or diclofenac will help initially. In principle, the knee should be immobilized. In addition, a cooling pad can be placed in the back of the knee. In addition to painkillers, selenium can be taken in capsule form. This micronutrient reduces inflammation in the body. The homeopathic remedy arnica also has an anti-inflammatory effect. This can be taken for acute treatment or after an operation. If there is no improvement within a day, the family doctor, an orthopedist or a surgeon should be consulted. If the cyst regresses but returns regularly, sufferers should take care to rest their knees. Sports that put a strain on the joints, such as tennis or soccer, should be replaced by swimming, gymnastics or cycling. Specific exercises – which can also be taught in physiotherapy (rehabilitation sports) – build up muscles that protect the knee joint and strengthen the musculoskeletal system. In addition, gentle exercise promotes the formation of synovial fluid. This reduces the risk of inflammation in the knee joint. Those affected who are overweight should try to reduce their weight in order to reduce the strain on the knees. If the person’s daily routine involves a predominantly sitting position, it is advisable to change the working position frequently. The purchase of a standing desk could support this.
