Knee Noise: Crepitus and Popping Explained When you bend or straighten your knees, or walk or travel up or downstairs, you may hear pops, snaps, crackles, and cracking sound in knee. This cracking sound is referred to as crepitus by doctors (KREP-ih-dus). Osteoarthritis is one reason for this, but there are a variety of additional reasons. Noisy knees aren't a concern in most circumstances. If you're experiencing discomfort in your knees, you should consult a doctor. Crepitus in the knees is not the same as crepitus or crackling in the lungs, which might indicate a respiratory issue.
A look at the Knee Joint
The knee functions as a big hinge. Bones, cartilage, the synovium, and ligaments make up the joint. Bones: The knee connects the thigh bone (femur) to the lower leg's long bone (tibia). The joint is also related to the fibula, a bone in the lower leg. The patella (kneecap) is a tiny, convex bone that lies in front of the knee and protects the joint. Menisci: The menisci are two thick cushions of cartilage that cushion the tibia and femur and minimize friction where they meet.