Atraumatic Knee Pain Differential Diagnosis | ITBS, PFPS, Jumper’s Knee
When a patient presents with atraumatic knee pain you will probably look into the direction of osteoarthritis, degenerative meniscus lesions, patellofemoral pain syndrome (PFPS), iliotibial band syndrome (ITBS), or patellar tendinopathy. We can split that list already based on age ranges where they are most prevalent. Osteoarthritis and degenerative meniscus lesions will be more prevalent in older patients, whereas the latter 3 are commonly seen in more active healthy young individuals
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Click here for a diagnostic cluster for knee osteoarthritis. In this post we want to focus on the latter 3: PFPS, ITBS, and patellar tendinopathy or jumper’s knee as they can be tricky to diagnose for some.
First of all, they’re a diagnosis of exclusion so ruling out any other injury whether that’s ligamentous or muscular is warranted prior. Furthermore, while you will find special tests for these clinical pictures on our website the tests perform weakly and may not add much to forming a diagnosis.
What you should rather look at is the clinical presentation of these three pathologies let’s move to the following table:
As you can see the 3 pathologies are subdivided into their primary pain location, the quality of the pain presentation, sport-specific risk – as they are rarely seen in the sedentary population -, the typical age of onset, and the pattern of onset. Already looking at the pain location and presentation you can rule out one third of the pathologies, as ITBS will have a sharp localized lateral knee pain
Patients with PFPS or patellar tendinopathy will have more anterior pain which may be diffuse in nature. So if the symptoms do not present laterally to the knee in a localized spot usually the femoral condyle rule out ITBS. On the flip side if the symptom is localized, sharp, and lateral it’s very likely not PFPS or patellar tendinopathy.
Let’s move on to the typical age of onset. As you can see ITBS and patellar tendinopathy are rather seen in adults, whereas PFPS is also prevalent in the adolescent population. Rathleff and colleagues conduct a ton of PFPS research in the adolescent population. Furthermore, if we had to describe the typical patient with PFPS it would be a teenage female runner
Lastly, the pattern of onset can give you clues in differentiating between the 3. While all of the 3 are overuse injuries and commonly result from a rapid increase in training load, the onset of symptoms and ITBS is usually sudden, whereas PFPS has an insidious onset developing over several weeks and increasing in severity So next time you have a patient with atraumatic knee pain remember these characteristics
If you want to learn more about PFPS or ITBS you can enroll in our online course The link is in the video description.
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