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Patello-femoral pain syndrome (PFPS), fat pad impingement

Discussion in 'Concerns after knee surgery' started by Josephine, Dec 24, 2010.

  1. Josephine

    Josephine NURSE DIRECTOR, BONESMART Administrator
    Thread Starter

    Member Since:
    Jun 8, 2007
    The North
    United Kingdom United Kingdom
    Not a very common condition but when people get it, it's often subjected to poor diagnosis from surgeons and thus poor treatment. Dr. Wayne Button, BSc, D.C produced this excellent treatise on the subject and rather than mess with his prose, I have decided to risk copyright and post it here in full. I hope he won't object!

    What exactly is PFPS? (Patello-Femoral Pain Syndrome)

    When you think about it what exactly does this diagnosis tell you? Essentially all that this means is we know there is pain and we know it has something to do with the Patella-Femoral Joint. In my opinion this is not a real diagnosis. What if we made clinical conclusions like this for everything? Chronic Neck Pain Syndrome or Sore Elbow Disease?

    In reality, PFPS is an umbrella term to describe any possible causes of pain which can be attributed to the Patella-Femoral Joint.

    Such as:

    - Chondromalacia Patella - Softening of the cartilage under the patella

    - PatellaFemoral tracking problems

    patellar shift.JPG

    - Infrapatellar Fat Pad being impinged (Hoffa's Disease)] (see next post)

    fat pad.JPG


    Originally many used to take a structural approach to PFPS. Measurements of one's Q angle or a patient's knee valgus was observed and often chondromalacia patella was diagnosed. However, if structural abnormalities were deemed the cause how does one explain the benefits from conservative treatment? The patients Q angle has not changed. Furthermore, not everyone with a high Q angle has knee problems?


    Researchers are starting to progress away from the structural approach of PFPS and asking what is actually causing the pain?

    A biomechanical fault, muscle imbalance or patho-physiological process which leads to:

    1. Inflammation of the synovial lining
    2. Inflammation of the fat pad
    3. Increase in intra articular pressure
    4. Hyperinnervated (folded in) Lateral Retinaculum

    To fully understand you have to address the signs and symptoms

    PFPS can be exaggerated with running and climbing up and down stairs. This mechanism of injury is simply due to overuse or excessive force. Such activities as climbing stairs can produce forces 3 times one's body weight. A loss of Tissue Homeostasis occurs and now the joint’s synovial lining becomes inflamed. This concept is a pretty easy one to understand.

    Reasoning for all these causes of pain has produced the popular treatment called McConnell taping.

    This is a taping method which has been shown to relieve pain. However, the results are not always consistent and many wonder why. It can be purposed that by taping the patella in a more neutral position we are preventing it from impinging structures and thus resolving the patient's pain.


    Lastly a maltracking patella has also been associated with PFPS. What studies have observed is anatomically those who suffer from PFPS have a hyperinnervated (very inward folded) lateral retinaculum (a membrane in the knee). Furthermore, these subjects presented with more hypersensitive fibers within the nerves. The theory is the patella tracking medially (usually) will produce tension along the lateral retinaculum. Now the nerves are put under traction and start to experience myxoid (phlegm-like) degeneration. In an attempt to heal itself the body produces more neural drive and stimulation to that area thus creating a hyperinnervated structure and pain is produced.

    In summary, as professionals we need to steer away from umbrella terms such as PFPS. This diagnosis is extremely confusing and so very difficult to explain to patients. To create consistency in research, we need to address the actual form of PFPS we are discussing. In addition, exploring this notion lays great premise on how we can guide our treatment. This is one condition where the diagnosis may actually be made after treatment is initiated.
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  2. Josephine

    Josephine NURSE DIRECTOR, BONESMART Administrator
    Thread Starter

    Member Since:
    Jun 8, 2007
    The North
    United Kingdom United Kingdom
    Re: Fat Pad Impingement, Hoffa's syndrome and PFPS

    Hoffa's syndrome:

    The Hoffa's pad is a pad of fat at the front of the knee joint, just below the patella. It acts as a shock absorber in the action of the joint. The true anatomical name is the infrapatellar fat pad.

    fat pad.JPG

    For various reasons defined in the article above, the pad can get pinched between the metal of the femoral component and the plastic resurfacing button on the patella. But it can happen in the absence of a patellar button.

    Whether it swells before or after the first impingements is unclear but swelling is part of the process as once it has been pinched a couple of times, it swells more and the consequently the pinching occurs more and more often. You know when you bite the inside of your cheek and it swells and protrudes so you bite it again? Well, that's pretty much what happens here.

    ~ the gold standard of ice and pain meds, especially anti-inflammatories
    ~ electrotherapy from a PT or a simple home TENS machine
    ~ muscle strengthening exercises to maintain the strength and fitness of the surrounding muscle groups
    ~ taping the patella (see McConnell taping in previous post)
    ~ injections of cortisone into the joint
    ~ in severe or persistent cases an arthroscopic trim of the fat pad might be indicated

    These acute on chronic conditions are a real bugbear and once begun, it's not easy to stop the cycle of pinch and inflammation causing pinch causing more inflammation, etc., etc.

    Some surgeons are more familiar with this relatively uncommon condition that others.
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