Value of knee MRI in the diagnosis and management of knee disorders

Orthopedics. 2014 Feb;37(2):e109-16. doi: 10.3928/01477447-20140124-11.


The primary objectives of this study were to determine how frequently knee magnetic resonance imaging (MRI) changes (1) diagnosis, (2) diagnostic confidence, and (3) management. A secondary objective was to correlate these changes with specific patient/physician characteristics and develop a prediction model using these characteristics. Six orthopedic specialists prospectively completed surveys when ordering knee MRI (n=93). Pre-MRI surveys recorded history, symptoms, signs, diagnosis, diagnostic confidence, and planned management. Post-MRI surveys recorded diagnosis, confidence, and planned management. Changes in diagnosis, management, and diagnostic confidence were correlated with patient/physician characteristics using chi-square and logistic regression tests. A multiple variable model was created with the most significant variables from the univariate analysis, and a c-index was used for cross-validation. Magnetic resonance imaging changed diagnosis in 29.3% and management in 25.3% of cases. Confidence in diagnoses after MRI increased, on average, by 10.6%. Change in diagnosis was significantly correlated with lateral joint line pain (P=.012) and tenderness (P=.006). The 3 most significant predictors for change in management were ligament pathology (P=.017), medial-sided pain/tenderness (P=.051), and age (P=.133). A 3-variable model using these predictors was significantly better than chance alone at predicting management changes (c-index: model=0.766; cross-validation=0.661). Magnetic resonance imaging frequently changed diagnosis and management and improved diagnostic confidence in a large minority of patients with internal derangement of the knee, even after evaluation by subspecialized physicians. A statistical model using specific patient characteristics can be created to predict when MRI will change management.

Publication types

  • Controlled Clinical Trial

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Aged, 80 and over
  • Critical Pathways / statistics & numerical data
  • Data Interpretation, Statistical
  • Female
  • Humans
  • Joint Diseases / diagnosis*
  • Joint Diseases / therapy*
  • Knee Injuries / diagnosis*
  • Knee Injuries / therapy*
  • Knee Joint / pathology*
  • Magnetic Resonance Imaging / statistics & numerical data*
  • Male
  • Middle Aged
  • Practice Patterns, Physicians' / statistics & numerical data*
  • Reproducibility of Results
  • Sensitivity and Specificity
  • Young Adult