Baker's cyst

Eliminating swelling and pain

Pain, reduced mobility, swelling at the back of the knee? This could be due to a Baker's cyst. For many patients, this condition causes significant limitations to their everyday activity. Often, sufferers also report feelings of numbness, circulatory problems or symptoms of paralysis below the knee.

Our experienced consultants at Schoen Clinic specialise in treating knee cysts. With effective treatment, we are able to eliminate the swelling and therefore your pain.  

Causes & symptoms

Baker's cyst of the knee: Causes of the condition

If the knee joint is inflamed or irritated, the body produces more fluid around the joint. The increased accumulation of knee joint fluid can lead to a condition known as a Baker's cyst: This causes rupture of the inner lining of the knee through the relatively thin, porous joint capsule on the flexion side. Ultimately, this results in the formation of a mucosal tissue sac.
The muscles situated to the side of the peduncle of the Baker's cyst press the tissue together and create a valve mechanism, preventing the return flow of the joint fluid. The cyst increases in size and can in extreme cases rupture in the area of the calf.

Causes may include:
  • Rheumatic inflammation of the joint
  • The result of bacterial knee inflammation
  • Mechanical irritation caused by meniscal damage, loose bodies in the joint, wrinkles in the mucosal tissue, ligament instability, cartilage wear or patellar instability

Baker's cyst of the knee: common symptoms

Patients with a Baker's cyst often complain of severe, usually non-inflamed swelling on the inside of the back of the knee. It often reduces maximum flexion of the joint and is accompanied by movement limitation or pain throughout the knee joint.
If the cyst ruptures, there is diffuse swelling of the entire calf and increased sensitivity to pressure with the typical signs of inflammation such as redness, swelling and excessive heat.


Diagnosis: How we diagnose a Baker's cyst

A Baker's cyst causes typical swelling in the back of the knee, which is often painful to palpation. Our specialists are usually able to recognise these easily during the clinical examination. To confirm the diagnosis, we also use primarily imaging-based procedures such as ultrasound, X-ray and MRI scans.


Using ultrasound examination, the suspicion of a Baker's cyst can be confirmed. The cyst's size can also be determined, along with its exact location. 


X-rays often provide clues to a potential cause such as arthrosis, loose bodies in the joint or an axis deviation.

Magnetic resonance imaging

Magnetic resonance imaging (MRI) allows the position and size of the Baker's cyst and the surrounding structures to be pinpointed exactly. The main aim of this investigation is to determine the cyst's proximity to the surrounding vascular and nerve fibres.