A Baker’s Cyst is a cyst filled with fluid that can form at the back of the knee. When symptomatic a Baker’s Cyst can result in knee pain.
The body produces synovial fluid to assist in lubrication of joints. This helps to reduce friction and make these joints easier to move. However, occasionally the body generates excessive synovial fluid. When this occurs in the knee, the synovial fluid collects behind your knee and forms a Baker’s Cyst. There are 2 main reasons for the increased production of synovial fluid. These are:
- Arthritis causing inflammation of the knee joint
- Torn cartilage (meniscus)
It is possible to have a Baker’s Cyst with no symptoms at all. However, when symptomatic common symptoms include:
- Pain in and around the knee.
- Swelling behind the knee. In severe cases this swelling can extend down the leg into the foot and ankle
- Reduced range of motion. In particular, the reduced ability to bend (flex) the knee
A detailed physical assessment is beneficial in the diagnosis of a Baker’s Cyst. The assessment should include range of motion testing, palpation, and observation of swelling patterns. Relevant medical history should also be discussed in relation to knee trauma or arthritic conditions.
Symptoms associated with a Baker’s Cyst can be similar in other common knee conditions so further investigation can be warranted. An x-ray will not show the cyst itself but can give an indication of degenerative or arthritic changes within the knee. To clearly see the cyst or excess fluid within the knee an ultrasound or MRI may be recommended.
Treat the underlying cause
In order to completely settle the Baker’s Cyst and prevent a recurrence the underlying cause must be adequately treated/managed. This may involve settling an acute aggravation of the arthritis or cartilage tear. Physiotherapy can assist with this through load management, activity modification, manual therapy, and a progressive exercise program. Medication may be appropriate if particularly aggravated, but this will need to be discussed with your doctor.
Physiotherapy has an important role to play in the management of a Baker’s Cyst. Manual therapy, such as soft tissue therapy, can assist in moving fluid for swelling management. This is particularly important to regain range of motion and reduce tightness. Cryotherapy (ice) and compression can also assist with swelling management. An exercise program should also be implemented and target stretching and strengthening exercises. Stretching exercises are important to promote tissue flexibility and fluid exchange. Strengthening exercises are important to progressively provide more knee support so the risk of aggravation decreases.
Cortisone can be used to treat underlying inflammation of the knee joint, as well as the inflammation associated with the Baker’s Cyst. Generally, cortisone provides short term relief of symptoms as opposed to fixing the problem. How long this relief lasts we cannot predict and is different for each individual. Cortisone injections will need to be organised through a doctor.
Draining the fluid
If the swelling persists and other conservative measures aren’t proving to be effective, it’s possible to drain the Baker’s Cyst. This is usually done by inserting a needle guided by an ultrasound into the cyst. By draining the cyst, it is hoped that individual’s can then complete exercises to address the underlying cause that they may not have being able to do before because of a large amount of swelling and pain.
As a last resort surgical removal of the Baker’s Cyst can be performed. This is usually considered if symptoms are severe and all other conservative measures have failed. Referral to see a specialist to discuss this option will need to be organised through your doctor.