What is Crepitus?
Crepitus is a crackling, grinding, grating, popping, or snapping sound or sensation that occurs with joint or tissue movement, which may or may not be accompanied by pain. 1
Clinical Definition and Characteristics
Crepitus manifests in two primary forms:
- Joint crepitus: A grinding or crackling sound on joint movement with an associated sensation in the joint, commonly found during physical examination in patients with osteoarthritis 1, 2
- Soft tissue crepitus: A palpable crackling sensation caused by gas in soft tissues, which in the absence of recent surgery, trauma, or puncture wound is a reliable indicator of infection requiring urgent evaluation 3, 4
Common Anatomical Locations
Knee Crepitus
- Defined as grinding, crunching, or crackling during movement, often assessed during squats with a palm placed over the patella 5
- Associated with osteophytes at the patellofemoral and lateral tibiofemoral joints, meniscal tears, and medial collateral ligament pathology 2
- Predicts incident symptomatic knee osteoarthritis, with higher frequency of crepitus correlating with increased risk (odds ratios ranging from 1.5 for "rarely" to 3.0 for "always") 6
Temporomandibular Joint (TMJ) Crepitus
- Occurs with jaw movement and is examined as part of TMJ assessment 1
- May be accompanied by pain radiating to the periauricular area, temple, or neck, with tenderness over the affected joint 1
Scapulothoracic Crepitus
- Production of grinding or snapping noise with scapulothoracic motion, which may be accompanied by pain 7, 8
- Always associated with scapulothoracic bursitis when symptomatic, though bursitis may exist independently 7
Sternal Crepitus
- Most commonly caused by sternal osteomyelitis, sternal fracture, post-sternotomy complications, or soft tissue infections with gas-forming organisms 9, 3
- Gas in soft tissues on imaging indicates infection and requires urgent intervention 3
Clinical Significance
Crepitus alone does not always indicate pathology—the key is distinguishing between benign and pathological crepitus based on associated symptoms and functional limitations. 1, 4
- In elderly patients, focus on functional limitations rather than crepitus alone, as meniscal tears are often incidental findings in those over 70 4
- Crepitus with pain, swelling, effusion, loss of motion, or tenderness warrants further investigation 1
- Soft tissue crepitus without recent trauma is highly suspicious for infection and requires immediate evaluation 3, 4
Diagnostic Approach
When crepitus is accompanied by concerning features:
- For joint crepitus: Physical examination includes palpation during movement, assessment of range of motion, and evaluation for associated symptoms 1
- For soft tissue crepitus: Radiographs are first-line imaging to detect soft tissue gas and bony abnormalities, with CT being most sensitive for detecting extent and location of gas 9, 3
- For suspected infection: MRI with contrast is preferred for osteomyelitis, and blood/tissue cultures should be obtained 9