Many healthy joints in the body, most commonly in the knee, present with joint noise called crepitus during range of motion testing. Crepitus can be an auditory cracking or popping sound or a sensation of grating in a joint. More concerning than joint noise is an associated sharp pain in the joint or associated locking, catching, or clicking of the joint. These signs and symptoms should be evaluated for potential injury to the joint surfaces and cartilage. If sharp pain or these mechanical symptoms are not present, joint noise or crepitus likely does not indicate an underlying injury to the joint. We often find crepitus in otherwise healthy knees. A recent research study reinforces our clinical understanding of joint crepitus in the knee joint.
Pazzinatto and colleagues examined 584 participants with crepitus and similar radiographic findings of knee arthritis in both knees (Braz J Phys Ther. 2018). These individuals were matched to peers of similar sex, body mass index, and presence of knee arthritis except these individuals did not have crepitus in either knee. Researchers had both groups, crepitus and absence of crepitus, perform both subjective measurements of pain and function, as well as, objective tests of strength, endurance, gait speed, and function. Authors reported lower subjective reports of pain, function, and quality of life in the group of participants with crepitus. Interestingly, they reported no difference in objective measurements or function. Authors concluded the presence of knee crepitus was not associated with objective function or strength measurements.