Popping and crackling noises in the knees while squatting or getting out of a chair are rarely symptoms of any injury or medical condition, the New York Times reported in its “Well” blog.
The crunching or grinding sensation, known as crepitus, sometimes results from gas bubbles popping in the knees. If there is no pain or inflammation, medical treatment is not needed, according to Dr. Michael Stuart, professor of orthopedic surgery and co-director of sports medicine at the Mayo Clinic.
In some cases, cartilage damage or meniscus tears cause crepitus. When cartilage in a knee deteriorates, the joint’s bones and tissues are no longer protected. They rub against one another, triggering inflammation and potentially leading to osteoarthritis. If left untreated, the pain and impaired mobility can reach the point that knee replacement (arthroscopy) becomes necessary.
“Crepitus is extremely common,” Stuart told the Times. “Our joints make a lot of noise.” He explained that, in addition to pain and swelling, a locking of the knees is a sign that treatment might be needed. Meniscus tears cause “mechanical symptoms like catching or locking,” he said.
Crunching or grinding sounds heard while squatting sometimes are indications of osteoarthritis. However, in the absence of inflammation and other discomfort, the sounds “may be innocuous,” according to Stuart.
He noted that deep squats, involving the hips dropping lower than the knees, put excessive strain on the knees. To prevent cartilage injury, it is advisable to exercise with more moderate squatting.
“When you perform a full squat, you put almost eight times your body weight across your knee cap,” Stuart told the Times. “Then, when you add a barbell or load on top of that, it ends up being very, very high forces to the joints and tissues around the knee.”
The noises associated with crepitus result from “an abnormal interaction (among) air, fluid or bone … when rough surfaces in a joint rub together,” according to healthgrades.com.
“Crepitus can be due to a wide variety of conditions, and associated symptoms can also vary widely,” the website reported. “Soft-tissue crepitus, due to air inside body tissues, is a serious type. Crepitus due to arthritis or joint problems can be a sign of chronic disease or joint damage.”
Symptoms of crepitus include joint pain, inflammation, stiffness that is more severe in the morning, skin warmth and redness, and reduced mobility. Healthgrades.com noted that signs of potentially life-threatening conditions are “bluish discoloration of the skin or lips, chest pain or pressure, confusion or loss of consciousness for even a brief moment, difficulty breathing, fever higher than 101 degrees Fahrenheit, nausea and vomiting.”
Subcutaneous crepitus, which occurs in soft tissues under the skin, requires immediate medical attention because it can be a symptom of a bacterial infection, wound or collapsed lung.
If you are experiencing crepitus associated with pain in your knees, schedule an appointment for an evaluation by the sports medicine surgeons at Orthopedic Surgery San Diego. They can diagnose the cause of the discomfort, whether it is knee osteoarthritis, a meniscus tear, cartilage injury or another condition. You can learn all your options, including knee replacement (also known as knee arthroplasty). Our specialists strive to offer you the best surgical and nonsurgical options.