Anterior knee pain, specifically known as “Patellofemoral Pain Syndrome” (PFPS), or in the past, “Chondromalacia Patellae”, is common and refers to pain in the region of your kneecap. The pain typically comes on gradually without specific trauma.
It has long been thought of as a benign condition… but is it? Here are some facts which have come to light across a range of scientific studies in the past 20 years (1):
Only 1 in 3 people with PFPS are pain free 1 year after diagnosis.
40% of people with PFPS still have the same level of pain 1 year later.
60% of people with PFPS report an unsatisfactory outcome 5-8yrs after diagnosis.
Up to 25% of athletes with PFPS stop playing sport due to the condition.
Doesn’t sound quite so benign now does it?
What has become clear is that PFPS is not a self-limiting condition, meaning that is does not go away by itself. It requires professional diagnosis and treatment, and a patient willing to do what is required to overcome the problem.
In order to treat any condition including knee pain effectively, we must first understand what the causes actually are. I say causes (plural) as multiple factors are involved. Traditionally the medical world has thought of PFPS as a biomechanical condition in which overload damages the kneecap joint (patellofemoral joint). Again, if we look at the science, this doesn’t appear to be the case for around 1/3 of people with the condition: in a study of adolescents with PF pain 1/3 didn’t actually play any sport at all whilst 2/3 played a lot of sport (5 times per week). So lots of physical load like running and jumping, whilst it can trigger pain in the kneecap, often isn’t the precipitating factor. Here are a few things to consider for causative factors:
Overload / training errors (too much too soon);
Biomechanical flaws – may be localised to the knee but not usually: weak hips, flat (or hyper-arched) feet, tight ankle joints & spinal concerns are more common contributing factors;
Muscle weakness – again local to the knee but more commonly in the hips or calves;
Referred pain – likely very important in the 1/3 of people who don’t have any overload to explain their pain!
What this means is that there are many “subgroups” of people with PF pain. This implies that every treatment should be highly specific to the individual person based on exactly what the causative factors are for them.
One thing is for certain – rest and wishful thinking have little effect on anterior knee pain. We know that many who develop PF pain are young. Adolescents are one of the most common age groups to develop the condition. This pain often persists into adult life, so ignoring the problem is dangerous as there is emerging evidence that it may lead to arthritis in later life.
My recommendations are:
1. Immediately unload your knee by stopping whatever it is that you are doing that aggravates the pain.
2. Seek the care of an expert Physiotherapist ASAP.
3. Diagnosis is important as there are many possible contributing factors.
4. Treatment needs to address all the causes.
Some thoughts on treatment options are listed below, as the specific combination of treatment offered really depends on exactly the combination of issues a given individual presents with.
1. Manual therapy treatment to the entire body produced excellent results in as little as 4 visits in a recent study (2). This is yet another example of how addressing the broader picture is far better than a myopic focus on the front of the knee.
2. Exercise therapy: strength work is of greater benefit if you are actually weak. In other words not everyone needs to do strength work if you are already strong enough. For those that do have weakness beware – squatting exercises can create 3-5 times body weight through the kneecap and flare your knee pain. It has been shown that addressing weakness in the entire kinetic chain is ideal (a kinetic chain being a series of joints all linked together in how they move – a bit like “the foot bone is connected to the shin bone…”). So evaluating exactly which areas need work is important.
3. Taping – is very popular and can provide short term relief of pain and short term enhancement of muscle function.
4. Orthotics – not everyone needs nor benefits from them. Orthotics are beneficial in those who have a genuine foot contribution to abnormal knee biomechanics (note that you can have flat feet which have little or no effect on the knee, or conversely flat feet can have a significant impact depending on a range of factors).
Patellofemoral Pain Syndrome is a clearly a challenging condition to treat if you want to become pain-free. It requires professional evaluation and expert, individualised treatment, including careful selection of exercises and manual therapy treatment. Often it requires some work and persistence on the part of the patient. If you think I’m kidding I’ll leave you with one other scientific fact: those that didn’t do their exercises were greater than 4 times more likely to still have their knee pain 1 year later (3)!
(1) Rathleff MS et al (2016): Patellofemoral Pain in Adolescence and Adulthood: Same Same, but Different? Sports Med.
(2) Tramontano N (2020): Assessment and Management of Somatic Dysfunctions in Patients With Patellofemoral Pain Syndrome. JAOA 120:165-173.
(3) Rathleff MS (2015): Exercise during school hours when added to patient education improves outcome for 2 years in adolescent patellofemoral pain: a cluster randomised trial. BJSM 49:406-412.