The Use of MRI in Evaluating Knee Pain in Patients Aged 40 Years and Older

J Am Acad Orthop Surg. 2016 Sep;24(9):653-9. doi: 10.5435/JAAOS-D-15-00681.


Introduction: The use of MRI is increasing when evaluating patients with knee pain because it is highly sensitive for detecting intra-articular pathology. However, such changes can be associated with degenerative joint disease, which may be demonstrated with weight-bearing radiographs. The purpose of this study was to determine how often MRI was obtained before orthopaedic referral in patients aged ≥40 years with knee pain, how often weight-bearing radiographs were obtained before MRI, and whether such imaging influenced treatment recommendations.

Methods: In a study of 599 new patients, participating physicians documented the presence of a prereferral MRI and/or plain radiographic studies, the results of weight-bearing radiographs, treatment recommendations, and the impact of any prereferral imaging.

Results: Prereferral use of MRI occurred in 130 patients (22%). Of these patients, plain radiographic studies were obtained for 58% before MRI and 13% had weight-bearing radiographs. Ultimately, 17% had weight-bearing radiographs that demonstrated >50% loss of joint space. Forty-eight percent of prereferral MRIs did not contribute to treatment recommendations. In patients with >50% loss of joint space, MRI was considered unnecessary in 95% of the cases.

Discussion: Many prereferral MRIs do not contribute to clinical decision making. Weight-bearing radiographs can help identify those patients in whom MRI is unlikely to be helpful.

Level of evidence: Level III.

MeSH terms

  • Adult
  • Arthralgia / diagnostic imaging*
  • Arthralgia / physiopathology
  • Diagnostic Errors / statistics & numerical data*
  • Female
  • Humans
  • Knee Joint / diagnostic imaging*
  • Knee Joint / physiopathology
  • Magnetic Resonance Imaging / statistics & numerical data*
  • Male
  • Middle Aged
  • Radiography / methods
  • Referral and Consultation / statistics & numerical data*
  • Weight-Bearing