If you have kneecap instability, you have probably been told that weak muscles around your knee are to blame. And while strengthening those muscles is an important part of managing instability, strength is only part of the picture.

A lot of times, kneecap instability is caused by differences in the knee’s structure, making it harder for the kneecap to stay in place.

Today, I’ll break down three most common conditions that can contribute to kneecap instability.

Patella Alta is when your kneecap sits too high in the trochlear groove. Because of the position of the kneecap, this makes instability episodes like subluxations and dislocations much more likely. Patella Alta is one of the most widely experienced kneecap instability condition and it is also the one that I have :)

Trochlear Dysplasia is when the groove that your kneecap sits in (trochlear groove) is shaped abnormally. These abnormalities can take several forms (shown in the image above). Trochlear Dysplasia is present in roughly 80-85% of recurrent kneecap instability cases and is a leading structural cause of kneecap instability.(https://radiopaedia.org/articles/trochlear-dysplasia)

Genu Valgum or Knock Knees, is when your knees angle inward and touch while your ankles are apart. This is very commonly seen in children but usually improves as they age. Having Knocked Knees puts a lot of force on your kneecap, which can cause it to dislocate outward.

This is a very important question and the answer is yes. In fact, kneecap instability often isn’t caused by just one factor. Someone might have patella alta along with trochlear dysplasia, or another alignment issue.

These factors can also work together. For example, a high-riding kneecap may take longer to settle into the trochlear groove, and if that groove is also shallow, the kneecap may have even less support keeping it in place.

That’s why figuring out the cause of kneecap instability isn’t always as simple as finding one problem. Doctors look at the knee as a whole, including patella height, trochlear shape, alignment, and rotation, to understand what may be contributing to the instability.

Thanks for Reading, See you Next Week!

Whether you’re managing kneecap instability yourself or simply trying to better understand your knees, I’m glad you’re here.

The Patellar Tracker is all about providing useful information, building a supportive community, and helping people with patellar instability stay active.

Thanks for being part of the journey. See you next week!