Crepitus

Crepitus is a crackling, popping, or grating sensation or sound that occurs with movement of a joint or with gas within soft tissues. It may be felt or heard and is most commonly noticed in the knees, shoulders, or fingers, but can occur anywhere. Crepitus can be categorized as articular (intrinsic to a joint) or subcutaneous (gas within soft tissues).

Causes

Articular crepitus is often related to degenerative joint disease such as osteoarthritis, chondromalacia, or rheumatoid arthritis, calcific tendinopathy, loose bodies, or cartilage wear. It can accompany normal aging or result from recent injury. Subcutaneous crepitus arises from gas in the soft tissues, which may be due to infection with gas-forming organisms (for example, clostridial species or anaerobes), trauma introducing air, surgical procedures, pancreatitis with subcutaneous emphysema, or thoracic or abdominal perforation with tracking of air.

Diagnosis

Evaluation includes history and physical examination. Imaging may show degenerative changes, loose bodies, and gas in tissues on CT or X-ray; ultrasound can detect soft tissue gas in some cases.

Management

Articular crepitus without signs of inflammation or acute injury usually requires no specific treatment; management targets the underlying disease and may include activity modification, analgesia, and physical therapy. Subcutaneous crepitus due to infection requires prompt antibiotics and possibly surgical intervention; extensive crepitus with chest or neck involvement requires urgent evaluation for pneumothorax or organ perforation.

Prognosis

Prognosis depends on the underlying cause. Degenerative crepitus is generally chronic and benign, whereas infectious or trauma-related crepitus may indicate a serious condition requiring urgent care.