The days of sneaking up the stairs to surprise the kids are over. Aside from the creaking boards on the 3rd and 7th step, my knees give me away long before I reach the third step.
Over the years I’ve noticed a sand paper grinding sound in my knees. At first it was in the right knee, but recently my left knee decided to join the symphony. It’s most noticeable when going up and down stairs.
Why are My Knees Crackling?
It appears that my knees are suffering from a condition called chondromalacia. Chondromalacia is the condition whereby the under surface of the kneecap (patella) suffers from uneven wear and tear.
Let me back this up just a bit to give a layperson’s explanation of the knee and how it works (I’m not a medical professional, just a gal with crackling knees). Below is a side view diagram of the knee (thanks to Wikipedia) :
This is how your knee looks when your leg is straight. That’s when the knee is silent.
The second image shows how the patella interacts with the femur during the bending process. This is when folks with chondromalacia hear the crackling sound. Things quiet down once the knee is bent.
Knee Cap Alignment.
The back of the knee cap isn’t flat. There is a ridge on the back of the patella that allows it to fit within the grove of the femur perfectly. It’s almost like the wheels of a train fitting perfectly on the track. When the wheels are properly aligned the train moves smoothly. If the wheel is pulled off the track, there are problems (not to mention ear piercing screeches).
As shown in the image from the Shelbourne Knee Center, in a properly functioning knee, the patella is located in the middle of the knee joint (not to the right or the left). The ridge on the back of the patella slides back and forth within the groove of the femur. Cartilage sits between the ridge and the femur which allows for a smooth noise free bending of the knee.
Poor Alignment and Crunching
Problems begin when the patella is pulled slightly to the right or left (most cases the patella is shifted toward the outer knee) and the ridge in the back of the patella no longer slides through the femur’s groove. Instead of sliding effortlessly, the femur comes into contact with the ridge on the back of the patella and the cartilage breaks down. Here’s where the symptoms differ depending on how severe the abnormal alignment, the extent of cartilage deterioration and whether or not arthritis has set in. For some folks find this condition is very painful and for others it’s more of a noise problem than a pain problem.
Know that I know why my knees are making so much noise; it’s time to find out what caused it and how to fix it.