Quick guide
Diagnostic approach
- Targeted clinical evaluation
- X-ray: initial imaging for most patients; see also “Ottawa knee rules.”
- CT: to evaluate complex fracture or dislocation
- MRI: suspected ligamentous or meniscal injury, or joint infection
- Ultrasound: effusion or bursitis
- Blood and synovial NAAT: suspected gonococcal arthritis
- Arthrocentesis with synovial fluid analysis: to help differentiate between subtypes of arthritis
- See “Diagnosis of septic arthritis” for labs for infection and inflammation.
Management checklist
- Uncomplicated musculoskeletal pain: RICE, pain management, WBAT
- Acute soft tissue injuries: stabilize with a functional brace
- Consult orthopedic surgery for patients with acute traumatic injuries, severe mechanical issues, or end-stage osteoarthritis.
- See also:
Red flag features
- Inability to bear weight
- Reduced range of motion
- Severe pain or swelling
- Fever or signs of infection
- Deformity or instability
- Decreased or absent pulses
- Signs of peroneal or tibial nerve injury (sensory loss, weakness)
- Knee dislocation or fracture
- Extensor mechanism disruption (patellar or quadriceps tendon rupture)
