It’s common for the knee joint to be very noisy, especially when performing activities such as squatting, climbing steps, or repetitive knee extensions. Patients frequently present to their chiropractor and ask, “Is that noise normal and should I be concerned?”
In most cases, crepitus (noise) emitted from the knee—which can include clicking, cracking, catching, snapping, popping, crunching, clunking, grinding and more—is physiologically normal. However, both clinicians and patients should be aware that crepitus may be a symptom of a pathological lesions. One study reported that several structural pathologies of the knee are associated with an increased risk of general crepitus in knee osteoarthritis (OA) while another study reported that crepitus may be the first symptom of patellofemoral-related(kneecap) conditions. Hence, it becomes the clinician’s duty to differentiate between physiological/normal versus pathological/abnormal crepitation.
When crepitus occurs in the absence of any history of injury, it may be simply physiological or normal, but it can also indicate a chronic or long-standing cartilage lesion in an OA knee and in other cases can be caused by inflammatory arthritis. These often carry a relatively long history of crepitus that may not hurt, or if it does hurt, not very much. Your chiropractor will perform range-of-motion tests, ligament stability tests, meniscus “click” tests, patellofemoral/kneecap apprehension tests, and more to tease out the safe from harmful click.
A general rule of thumb is that pain-free crepitation is usually physiological and not to be of concern while a painful crepitation should be investigated. In order to put the patient’s mind at ease, your doctor of chiropractic will perform a detailed history and examination to differentiate between knee-related noise that is safe versus pathological. For example, a history of an immediate onset of pain associated with “a pop” during an activity may indicate an acute injury such as a root tear of a degenerative meniscus and/or a detachment or tearing of a ligament inside the joint (such as a cruciate ligament) or on the sides of the knee (such as a collateral ligament). An acute injury is usually accompanied by pain, swelling, and limited motion, which most definitely requires a thorough evaluation. A past history of an acute knee injury can also be very important.
Ultimately, the treatment approach to reduce knee-related noises can vary depending on the ultimate diagnosis. In addition to manual therapies and or physiotherapy modalities delivered during office visits, patients may be instructed on exercises to stretch right tissue and strengthen weakened muscles. If ankle/foot pronation is adversely affecting the knee angle, the patient may be prescribed an orthotic to address ankle/foot posture, which may take the excess pressure off the knee that may be causing the noise to occur.