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.
Synovium is a kind of connective tissue that lines the insides of joints and tendon sheaths. The synovial fluid lubricates the joints. Ligaments: The bones are connected by four ligaments, which are strong, flexible bands that extend over the uneven surface of the joints.
Causes Apart from osteoarthritis, crepitus can occur for a variety of causes. Here are a few examples: Bubbles of gas Gas can build up in the regions around the joint over time, resulting in small bubbles in the synovial fluid. Some of the bubbles pop as you bend your knee. This is quite natural and happens to everyone at some point. It doesn't create any discomfort. Ligaments As they travel over a tiny bony bulge, the ligaments and tendons around the knee joint may extend somewhat. A clicking sound may be heard in the knee when they snap back into place. Instability of the patellofemoral joint. Patellofemoral instability Every person's body is a little bit different. The numerous tissues and components that make up the knee differ from person to person, whether due to birth, age, injury, or life experiences. For example, your knees may flex more than someone else's, or your kneecaps may move more easily. Because of these variances, one person's knees may be louder than another's. Injury: Injury Crepitus can also be caused by a traumatic event. The kneecap or other elements of the knee joint might be damaged if you fall on your knee. Crepitus is a symptom of this type of injury. Meniscus tears are quite prevalent in athletes, joggers, and runners. As the joint moves, a torn meniscus can induce crepitus. Damage to the undersurface cartilage of the kneecap is known as chondromalacia patella. A dull aching behind the kneecap might occur as a result of overuse or injury.
When you apply too much weight to the patella, you get patellofemoral syndrome or runner's knee. It occurs before damage to the patella's joint surface begins, and it can progress to chondromalacia patella. When you move your knee, you may notice a painful crushing and grinding that you may see or hear.