Apart from clinical examination multiple modalities (conventional radiography, MRI and arthroscopy) are currently used to evaluate knee injuries. This study is intended to compare the sensitivity and specificity of MRI in correlation of arthroscopy in diagnosing of knee injuries.
Material & Methods: This is a prospective study involving 51 patients with history of knee injuries who were admitted in the Department of Orthopaedics, in a tertiary care hospital of Kolkata between April 2013 and June 2014. MRI of the knee joint was done for all these patients either before or after admission. The patients were then subjected to diagnostic and therapeutic arthroscopy. Statistical analysis was used to calculate the sensitivity, specificity, positive predictive value and the negative predictive value, in order to assess the reliability of the MRI results.
Results: The sensitivity and specificity of MRI with respect to arthroscopy in anterior cruciate ligament tear is 87.5% and 66.6%.Positive predictive value is 87.5%. Negative predictive value is 66.6%.Accuracy is 81.82%. The sensitivity and specificity of MRI with respect to arthroscopy in medial meniscal tears is 85.7% and 70.8% respectively. Positive predictive value is 63%; Negative predictive value is 89.4%; Accuracy is 76.3%.
Conclusion: The present study supports that MRI is helpful in diagnosing medial meniscal and anterior cruciate ligament injuries. The negative predictive value of a MRI was found to be high for all structures of the knee joint and hence a MRI can be used to exclude a pathology, thus sparing patients from expensive and unnecessary surgery.