Abstract
Magnetic resonance imaging (MRI) scans are widely used in the assessment of knees, often prior to arthroscopic procedures. The reporting of chondral damage on MRI scans can be variable. The correlation between MRI reports of chondral damage and that found at arthroscopy is often inconsistent. The aim of this study was to identify how well MRI reports correlated with the extent of chondral damage found at arthroscopy. A retrospective case-note review of a single-surgeon series of 175 arthroscopic procedures was performed. 83 patients were included in the study. The remainder were excluded if an MRI scan had not been performed, or had been performed more than 3 months prior to surgery. The condition of the articular cartilage demonstrated by MRI was compared to that found at arthroscopy. Data was analysed for presence and extent of chondral damage. Comparison between MRI and arthroscopy findings showed high Specificity (90%) and Negative Predictive Values (89%) for chondral damage, but low Sensitivity (46%). Cohen's kappa values < 0.2 revealed very poor correlation for the extent of damage. This study demonstrates that MRI is good at describing whether articular damage is present but does not reliably describe the extent of the damage.
