Orthopedics-Online

Popliteal cyst

Synonyms: Baker's cyst, popliteal cyst, synovial cyst

definition

The popliteal cyst is a protrusion of the posterior capsule of the knee joint as a result of increased pressure in the knee joint (joint effusion).

Emergence

The Popliteal cyst or Baker's cyst is not a disease, but rather a symptom of one irritation and one Pressure increase to understand in the knee. Since the popliteal cyst or the posterior joint capsule is directly connected to the joint space, the cyst can, depending on the production of the Synovial fluid take on different dimensions.

Due to its diverse causes, which are common, the popliteal cyst also occurs more frequently. The likelihood of a popliteal cyst increases with age, but can generally occur in any generation.

Please also read: Baker's cyst in the knee

Symptoms

Popliteal cysts can develop on one or both sides (e.g. in rheumatism or osteoarthritis). A popliteal cyst is not always noticed by the patient, especially if it accompanies painful injuries. People with popliteal cysts can be symptom-free or sometimes complain of pain in the hollow of the knee that cannot be precisely localized and radiates to the adjacent thigh or calf. In most cases, a resilient bulge can be felt, which increases in size depending on the load and can shrink again after several days of rest so that it can no longer be felt. As the popliteal cyst swells, increasing swelling of the entire knee joint is often noticed.

Read more on the topic: Swollen hollow of the knee

Depending on the pressure, the popliteal cyst can press on nerves, veins and arteries in the hollow of the knee, causing swelling, circulatory disorders, restricted mobility and numbness in the calf and foot.

If the popliteal cyst is severely swollen, the wall of the joint capsule can become thin and burst. In this case, the synovial fluid spreads to the surrounding tissue and swelling can occur from the foot to the calf. A bang is often felt in the hollow of the knee at the moment of the burst.

A possible complication of a pronounced popliteal cyst is a compartment syndrome.

Appointment with a knee specialist?

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The knee joint is one of the joints with the greatest stress.

Therefore, the treatment of the knee joint (e.g. meniscus tear, cartilage damage, cruciate ligament damage, runner's knee, etc.) requires a lot of experience.
I treat a wide variety of knee diseases in a conservative way.
The aim of any treatment is treatment without surgery.

Which therapy achieves the best results in the long term can only be determined after looking at all of the information (Examination, X-ray, ultrasound, MRI, etc.) be assessed.

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60311 Frankfurt am Main

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causes

Pathophysiologically, the development of the popliteal cyst is an irritation of the Synovial membrane (Synovium) is based. As a result, it produces more synovial fluid to counteract the stimulus. There is overpressure in the joint space and bulging of the joint capsule at its weakest point between the approaches of the Calf and thigh muscles.

The trigger for such irritation of the synovial membrane can be previous accidents (e.g. menicus damage, cruciate ligament rupture), Gonarthrosis (Knee osteoarthritis), rheumatoid arthritis, bacterial inflammation, etc.

Bursted popliteal cyst

When the popliteal cyst due to increasing in size burst is felt by those affected suddenly shooting in, strong pain in the lower leg. The contents of the cyst, consisting mainly of Synovial fluid, then runs along the calf muscles downward. Then a Inflammatory response With overheat, Redness and Swelling of the lower leg observe.

In the worst case, the so-called arises on this basis "Compartment Syndrome" with strong Swelling of the calf muscles and then Relocation of the blood vessels. Due to the lack of blood supply, Parts of the muscles die off. This clinical picture presents one absolute emergency With strongest pain dar and must operated on immediately become. Otherwise it threatens Loss of leg.

Read more about the topic here: Compartment syndrome

Much more common than a "real burst" popliteal cyst, decreases in size are caused by the underlying knee damage. The cyst can increase in size when the load is exerted and then decrease again when the joint is relieved. This mechanism can give the impression of a simulate a burst cystbut does not cause severe pain.

diagnosis

Since similar symptoms are caused by a thrombosis, Pulled muscles, Lipomas and other Lumps or Vascular aneurysms can be triggered, it is important to exclude them by means of diagnostics.

A previous knee joint injury, osteoarthritis or rheumatism is typically found in the medical history.

In addition to the manual examination of the knee and the hollow of the knee with an often palpable, non-pulsating bump in the hollow of the knee and otherwise soft calves and thighs, this is used Ultrasound machine (Sonography) for diagnosing the popliteal cyst.

Furthermore, the Magnetic resonance imaging (MRI) for diagnosis. This is mainly done to identify the cause of the popliteal cyst, such as Find meniscal injuries.

If one cannot find a cause for the development of the popliteal cyst with the aid of the diagnostic apparatus, one can use a Joint puncture Gather synovial fluid for microbiological examination. This examination can detect bacterial inflammation of the knee gap.

therapy

A popliteal cyst only needs surgery if it causes serious symptoms. The operation is usually carried out arthroscopically, i.e. as part of a joint endoscopy.

Since the popliteal cyst itself is only that symptom knee disease, this should be treated above all in order to be able to treat it successfully in the long term. If the popliteal cyst was found by chance and there are no symptoms, therapy is not indicated.This can be done with minor complaints Cool of the knee with ice or cooling packs, reduce the effusion in the joint space, shrink the popliteal cyst and thus alleviate the symptoms. The popliteal cyst can decrease with the joint effusion, for example by Protectionregress to the point where it is no longer palpable and no longer causes any discomfort. If the popliteal cyst causes such severe discomfort that it restricts the patient, you can puncture it and thus relieve the knee joint gap.
A surgery is generally possible, but is not recommended due to the risks and poor results in the long term.
The exception is the rheumatic popliteal cyst. Here, aggressive mucosal tissue, known as pannus, forms in the popliteal cyst, which can attack and damage the surrounding tendons.
In the case of a rheumatic popliteal cyst that does not improve with conservative / alternative treatment, surgery is usually necessary, taking into account the overall condition.

Surgery of the popliteal cyst

Not every popliteal cyst has one OP necessary. Surgical removal can only be carried out with increasing size and associated restrictions makes sense be. Often those affected then report Pain, Numbness, Circulatory disorders or decreased mobility of the knee joint.

In the vast majority of cases, the popliteal cyst represents just that "Tip of the iceberg" The real problem, however, usually lies in the Inside the knee joint. E.g. Meniscus damage or Osteoarthritis of the knee be causally responsible. In the case of an operation, this is primarily the case Fixed problem in the joint rather than removing the cyst itself. Because if the underlying knee damage can be eliminated, the popliteal cyst usually disappears afterwards by itself.

Very rarely, however, it may also be necessary Liquid-filled sac remove directly. In such cases are mostly children affected, whose Popliteal cyst discomfort caused by increasing size. As an alternative to surgery, a thin needle punctured and the fluid discharged from the cyst. However, here is the Risk of recurrencebecause the cause has not been eliminated.

Appointment with a knee specialist?

I would be happy to advise you!

The knee joint is one of the joints with the greatest stress.

Which therapy achieves the best results in the long term can only be determined after looking at all of the information (Examination, X-ray, ultrasound, MRI, etc.) be assessed.

You can find me in:

Lumedis - your orthopedic surgeon
Kaiserstrasse 14
60311 Frankfurt am Main

Prophylaxis and prognosis

Prophylaxis in the strict sense cannot be used. If you know of a popliteal cyst, you can limit your activity in the event of severe symptoms in order to reduce the swelling. However, if you are unable to exercise, you should think about one of the above therapies together with your doctor in order to prevent further general illnesses. The chance of getting rid of a popliteal cyst depends heavily on the underlying diagnosis.

If the underlying disease is knee osteoarthritis (Gonarthrosis), it can be assumed that the patient - depending on the actual symptoms of osteoarthritis - will also have a more or less symptomatic popliteal cyst until the end of his life. However, if the popliteal cyst has suffered an acute injury to the meniscus in the knee joint, it is to be expected that after healing or surgical treatment of the meniscus damage, no relevant symptoms of a popliteal cyst will be perceived. Neither the knee puncture, with the suction of the synovial fluid from the cyst, nor the surgical therapy are always satisfactory. The cyst sometimes has several partitions (septa) so that only a certain part of the fluid can be drawn off during the puncture. Since the connection between the extended joint capsule (former cyst) and the joint space is retained despite this therapy, the wall can bulge again and the sac can fill with synovial fluid. The risk of the popliteal cyst recurring is high.