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Don't order MRI of the knee for atraumatic knee pain with a degenerative clinical picture before weight-bearing radiographs. Setting: atraumatic knee pain with a degenerative picture (crepitus, chronicity, age-consistent osteoarthritis features) and no weight-bearing X-ray yet performed; does not apply when examination suggests internal derangement (e.g. positive McMurray or Lachman) or acute trauma Why: In degenerative knee pain, weight-bearing X-rays establish the diagnosis at a fraction of the cost; age-related meniscal MRI signal is near-universal and drives unnecessary arthroscopy. Consider instead: weight-bearing (standing) knee radiographs first; MRI only if examination suggests internal derangement or surgery is being planned Source: American Academy of Orthopaedic Surgeons (Choosing Wisely, US, 2013).