the Knee Bursae: some hints

The bursae of the knee can be defined in a very simple way: they are fluid sacs, or synovial pockets. This second definition comes from the sinovial fluid that fills them.

Synovial fluid is made of hyaluronic acid and lubricin, proteinases and collagenases. Its main functions are reducing friction by lubricating the joint, absorbing shocks and properly “feeding” joint cartilage. In the case of the knee, the Knee Capsule encloses the Knee Cavity which is filled with synovial fluid. Knee Bursae surround and sometimes communicate with the Knee Cavity, as we can see in the picture.

Usually Knee Bursae are thin-walled and represent the weak point of the joint. At the same time, their presence is really important since they enlarge the joint space. They can be grouped according to:

  • their characterization as communicating and non-communicating bursae. A communicating bursa is when a bursa is located adjacent to a joint, thus having the synovial membrane in communication with the joint itself.
  • their location (frontal, lateral, medial).

In pathological conditions, such as excessive local friction, infection, arthritides or direct trauma, fluid and debris collect within the bursa or fluid extends into the bursa from the adjacent joint. As a consequence, the walls of the bursa thicken as the bursal inflammation becomes longstanding. The term bursitis refers to pathological enlargement of the bursa. Clinically, bursitis mimics several peripheral joint and muscle abnormalities.


<–prepatellar bursitis

          elbow bursitis–>



sources: Wikipedia and this website


5 thoughts on “the Knee Bursae: some hints

    • thank you for your comment 🙂
      Yes, bursitis can be really painful… I didn’t emphasize the patological side of knee bursitis but actually I wonder how one could reduce the pain and start a healing process without hospitalisation… do you think it is possible with some “home-made” treatment? or are medicaments the only way out?

  1. Pingback: let’s take stock of … the lower limb ! | andreacollo

  2. You actually make it seem so easy with your presentation but
    I find this topic to be actually something which I think I would never understand.
    It seems too complicated and extremely broad for me.
    I am looking forward for your next post, I will try to get the hang of it!

    • Hey, thank you for your visit and for your nice words!
      Be aware that each post doesn’t provide a complete description of the topic. My approach is, in a sense, “superficial” since I always try to present complicated stuff in simple words. In order to do that, I’m obliged to “cut” parts that instead should be better explained… but already it takes me at least one hour to write a half-page post, the “selection process” of the webpages I read to get documented and check details is quite long 🙂
      Especially this post, about Knee Bursae, is not complete at all and just gives some hints (as the title suggests). I hope I’ll be able to improve the quality of my posts with time. If there’s any topic about which you would like to read a post, PLEASE TELL ME!!! And I’ll be happy to study something new 🙂
      ciao, Andrea

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