Test your knowledge!
Whether you’re a physiotherapist, general practitioner or orthopedic surgeon: a lot of us have seen this before in their practice. A typical knee problem, most of the times resulting from an underlying pathology. What is the relationship between these 4 pictures? What do you see in the images on top? What are possible causes for this problem? And what do you see in the picture bottom right? The answer can be found low the picture!
The right answer was: a Baker's Cyst or popliteal cyst.
A Baker's cyst consists of joint fluid which bulges into the popliteal fossa. Most of the times, this process is a result from hydrops in the knee joint. Through a passage between this cyst and the knee joint capsule intra-articular fluid can pass and when pressure is built up, the joint fluid bulges into this recess. Meniscal tears are one of the main causes of accumulated intra-articular fluid. Musculoskeletal ultrasonography is a useful tool to examine the popliteal fossa; in the picture you can see a Baker's cyst (black oval structure). For the fanatics: can you recognize the vertical meniscal tear? - In this case the Baker's cyst is probably caused by a meniscal tear.