Your Guide to Acute Knee Pain

Everything you need to know for your just injured knee

Imagine this: you're out for a run, enjoying the rhythm of your footsteps and the fresh air around you, when suddenly, a sharp pain in your knee stops you in your tracks. Or perhaps you're simply getting up from your desk after a long day of work, and that familiar, unwelcome ache in your knee rears its head again.

Did your break something? Sprain something? Is it your meniscus? This guide will cover all your acute knee pain issues and let you make the best informed decision about what to do next

Did you break your knee?

There’s a very simple cluster of tests known as the Ottowa Knee Rules. Simply, if the answer is “yes” to any of the questions below, it is time for an x-ray. This does not mean you for sure have a fracture, but you need an x-ray to rule one out

1. Are you over the age of 55?

   1. Sorry. I don’t make the rules. As we age, we lose bone density (generally). The odds of you being 60 and stepping off a curb and breaking your knee are just much higher than if someone half your age did the same thing.

2. Is there tenderness on the head of the fibula?

   1. This is where the head of your fibula is. Push on this spot. Lot of pain? Get an x-ray. The exceptions to this rule is if there is trauma to the area such as a cut or burn. If you press on a burn it is going to hurt. Please don’t overcomplicate this

      

3. Is your patella (knee cap) tender to the touch?

   1. Self explanatory. You blew your knee out stepping off a curb wrong and your knee cap hurts? X-ray

4. Are you unable to fully bend your knee?

   1. Textbook says the goal here is at least 90 degrees. I know you don’t have a protractor and compass on hand so we’re not gonna get too specific on that. If your knee doesn’t bend after an injury, get an image. None of the good clinicians actually truly gets that specific with measurements in a clinic anyways.

5. Are you unable to take 4 steps or completely weight bear?

   1. If you can’t put weight on an injured knee you need an image. Its that simple. No need to elaborate further.

Did you tear your meniscus?

Sometimes, it doesn’t take much to tear a meniscus. I personally know someone that missed the hole in their jeans, stepped awkward and tore their meniscus. I’m looking at you mom

Here is a cluster of 5 tests to help determine if a meniscus is torn. If all 5 are positive then there is a 92% chance of a meniscus tear (highly likely). If 3-4 are positive then its a 75% chance of a tear. Don’t ask what less than 3 means cause I don’t remember

1. Do you have mechanical symptoms in your knee?

   1. Straightforward here. Your knee should not click, pop or catch. If it does, this test is positive

2. Do you have pain with forced extension (straightening) of your knee?

   1. If you are unable to fully extend your knee, a meniscus tear may be preventing that motion as it is getting pinched between your tibia and femur.

3. Pain with maximum flexion (bending) of the knee?

   1. Same logic applies here as with knee flexion. Torn fibers from a meniscus tear can get in the way.

4. Joint line tenderness?

5. Positive Thessaly test

Is your knee sprained?

Quick anatomy break. If you don’t care and want to skip to the program, I don’t blame you.

Lets quickly discuss the forces that act on the knee so you understand what the terms from the list above mean

1. Translation – the low leg moves forward or backwards against a fixed thigh (anterior/posterior)

   

2. Angulation – the low leg bends in or away from a fixed thigh (varus/valgus)

   

3. Rotation – the foot does not move and the low leg rotates away from the foot

4. Axial load – vertical force usually from landing from height

5. Direct blow – your knee strikes something

Your knee has 5 main ligaments I’m going to address for the sake of this post. I’ll mention the most common force to cause damage to each ligament. Keep in mind this will be textbook and in the real world, rarely is anything isolated

• ACL - anterior translation. Non contact, hyperextend your knee

• PCL - posterior translation from a direct blow. Commonly happens in a car accident and your knee hits the dash

• MCL - valgus force. Someone hits you on the outside of the knee

• LCL - varus force. Someone hits you on the inside of the knee

• MPFL - rotation. Your foot is planted in the ground and you rotate your body away. Typically your knee cap pops out of place (subluxes)

In the future, I’ll break down the knee ligaments in depth. For now, this is enough to get you to start the acute care

Now What?