Rose, Romer E. C.; Bullock, Richard; Crawford-Sykes, Annette; Adams, P.
Author Affiliation, Ana.
The Accuracy of MRI in the diagnosis of Knee Chondral Lesions.
Internet Journal of Orthopedic Surgery
Date of Publication
Objective: To evaluate the sensitivity, specificity, and accuracy of routine 1.5-Tesla MRI in detecting chondral lesions of the knee. Method: This is a retrospective review of 300 knee arthroscopic procedures performed between January 2004 and September 2008. Nineteen patients were included in the study. MRI was performed in a 1.5-Tesla machine, with proton density, T1 and T2 sequences in axial, coronal, and sagittal planes. The pre-operative MRI scans were performed by a single radiologist. For the purpose of this study, the MRI scans were re-evaluated by the same radiologist who was unaware of the prior results at arthroscopy. Chondral lesions were classified at the time of arthroscopy according to the Outerbridge classification. The MRI report of at least one chondral lesion found at arthroscopy was considered as a positive correlation between both diagnostic instruments. Results: Of the 19 patients, 11 (58%) were females and 9 (42%) were males, with an average age of 38 years (range 11 years – 64 years). There were 26 lesions in 14 knees. Chondral lesions showed a predilection for the medial femoral condyle (30.7%). The majority of cartilage lesions were grade III (41.9%). MRI had a sensitivity of 21.4%, a specificity of 100%, and an accuracy of 42.1%. Conclusions: Our study shows that routine 1.5-Tesla MRI is not sensitive, but is specific and somewhat accurate in detecting articular cartilage lesions. Arthroscopy cannot be replaced by 1.5-Tesla MRI in detection of cartilage lesions.....