
Baker’s cyst is a buildup of joint fluid (synovial fluid) that forms a cyst behind the knee.
Baker’s cyst is a buildup of joint fluid (synovial fluid) that forms a cyst behind the knee.
A Baker’s cyst is caused by swelling in the knee. The swelling is due to an increase in synovial fluid – the fluid that lubricates the knee joint. When pressure builds up, fluid bulges into the back of the knee. Baker’s cyst commonly occurs with:
• A tear in the meniscal cartilage of the knee
• Knee arthritis (in older adults)
• Rheumatoid arthritis Other knee problems