What is Baker’s Cyst (Behind the Knee Pain)? Causes and Treatment

by Abbas Jahangir · June 22, 2024

Baker’s cyst, also known as a popliteal cyst, is a fluid-filled swelling that forms as a lump behind the knee. This swelling often causes complaints of tension and limitation of movement. If the knee is extended, it may result in pain. Conditions such as arthritis or cartilage damage that affect the joint structure in this region may play a role in the formation of Baker’s cyst. Identifying these underlying problems can also help eliminate the cyst. Baker’s cyst, which does not cause any problems in the long term, can have a very disturbing course in some people. In rare cases, Baker’s cyst may rupture and progress downwards along the calf muscle and manifest itself with the development of a bruise around the ankle.

What is Baker’s Cyst?

Baker’s cyst was named after Dr. Dr., who was a physician in the mid-1800s. Named after William Morrant Baker.

Baker’s cyst is a fluid-filled sac structure that forms in the back of the knee. The development of Baker’s cyst in adults usually occurs during a degenerative process. In children, Baker’s cyst may occur as a result of herniation of the knee joint capsule, although it is not due to any other condition. Baker’s cyst causes tension and fullness in the back of the knee. Pain associated with Baker’s cyst occurs when bending the knee, especially when people are active.

What Causes Baker’s Cyst?

The knee joint, like other body joints, contains fluid-filled cushions called bursa around it. These structures allow the joints to continue moving without friction. If there is excessive fluid production in the knee, these bursa structures may swell and cause the formation of a Baker cyst. These cysts can be painful in some people and restrict the movement of the knee.

Baker’s cyst is a problem that can occur in any individual. However, there are two age groups in which it is particularly seen. These are childhood between the ages of 4-7 and adulthood between the ages of 35-70. The formation of Baker’s cysts is usually observed after an injury such as a fall. Chronic (long-term) joint problems may also play a role in the formation of cysts in some people. In some cases of Baker’s cyst, the underlying cause may not be elucidated. In general, meniscus tears, inflammation of the knee joint (arthritis), rheumatoid arthritis and other inflammatory joint diseases are the most common diseases that play a role in the formation of Baker cysts.

What are the Symptoms of Baker’s Cyst?

In some cases of Baker’s cyst, no complaints may occur. The complaints that occur with the development of Baker’s cyst in some people can be summarized as follows:

Moderate or severe pain
Rigidity
limitation of movement
Swelling at the back of the knee
Redness in the knee, calf or ankle area

These symptoms may increase in some people during physical activity or standing for long periods of time.

Does Baker’s Cyst Turn into Cancer?

Baker’s cyst does not turn into cancer, but care should be taken because it may show similar symptoms to a mass or another important health problem, such as the development of a clot in the leg veins. Especially if the cyst ruptures and causes color change in the ankle area, it is recommended to consult healthcare institutions to clarify whether this is due to a clot or a rupture of the cyst.

How is Baker’s Cyst Diagnosed?

In the diagnostic approach to Baker’s cyst, physicians first perform a physical examination of the knee and detect the swelling behind it. In cases where the cyst is small, they can examine the decrease in joint range of motion by comparing the affected knee with the healthy knee.

In cases of Baker’s cyst that increases in size of the cyst or is accompanied by severe pain, radiological imaging examinations such as magnetic resonance imaging (MRI) or ultrasonography (USG) may be used. Magnetic resonance imaging allows the cyst to be seen easily and is effective in clarifying whether the underlying cause is joint damage. These radiological tests also allow evaluation of whether the cyst is a tumor or other tissue growth.

How is Baker’s Cyst Treated?

Treatment of Baker’s cyst usually begins with non-surgical methods. The main methods recommended by experts after any joint trauma are resting this area, putting ice on it, applying pressure and keeping it elevated. It is recommended that people with Baker’s cyst avoid activities that may cause excessive strain on the knee.

Apart from these applications, you can use painkillers as prescribed by your physician. Steroid injections may be used in some individuals as part of the treatment of Baker’s cyst. These drugs injected into the joint space can help control edema and pain by suppressing inflammation.

Physical therapy and rehabilitation practices are an important part of the treatment of Baker’s cyst. Through regular and gentle exercises, the muscles around the knee can be strengthened and these exercises can contribute to increasing the range of motion of the knee. In individuals with severe pain complaints, walking with the help of a cane or wand is among the practices that can be used to control pain.

Proper treatment of Baker’s cyst is very important to prevent its recurrence. In individuals suffering from arthritis (joint inflammation), surgical intervention may be considered if joint damage is determined to be the main cause of cyst formation.

Surgical procedures are rarely used in the treatment of Baker’s cyst. In some cases, the reason for surgical methods is to correct the injury underlying the cyst formation. Treatment of Baker’s cyst with surgery is especially recommended for people whose knee pain is unbearable and whose joint range of motion is severely restricted. In some cases of Baker’s cyst, the surgeon can focus directly on the cyst and remove it with various procedures:

Drainage

After applying to healthcare institutions with the complaint of Baker’s cyst, physicians may try to evacuate the contents of the cyst using a needle under ultrasonography. In cases of severe Baker’s cyst, results may not be obtained with the drainage method alone.

Arthroscopic Knee Surgery

Arthroscopic knee surgery is a procedure that provides both diagnosis and treatment for injuries to the knee joint. In this operation, physicians make a small incision in the knee area and then insert a flexible arthroscope with a camera at its tip into the knee through this opening.

Knee Osteotomy

In knee osteotomy surgery, physicians remove some bone structures to correct the damage in the knee area. This procedure can be an important treatment option, especially for people suffering from knee pain due to arthritis.

Does Baker’s Cyst Go Away on Its Own?

It is common for Baker’s cyst to resolve spontaneously in some people. Sometimes there are cases where the cyst bursts under the skin and the leaking fluid is then absorbed by the body. However, in order to eliminate the Baker cyst and prevent it from occurring again, the underlying cause of the formation of this cyst must be treated.

What Situations May Occur If Baker’s Cyst Is Untreated?

Some Baker cysts may remain untreated. This is due to the fact that people who experience mild pain neglect these cysts. Although there is a possibility that the cyst will go away on its own in some individuals, in some cases of untreated Baker cyst, complications such as worsening of pain over time, increase in the size of the cyst, and red-purple discoloration in the leg may occur as a result of the cyst bursting.

The fact that the cysts that have formed have not resolved spontaneously within a certain period of time may indicate that it is necessary to seek support from specialist physicians by applying to health institutions.