Accuracy of MRI in Detection of Meniscal Injury when Compared with Knee Arthroscopy

Abstract

Objective: The study aims to establish the level of diagnostic accuracy of magnetic resonance imaging in detecting meniscal injury with knee arthroscopy as the gold standard. Study Design and Setting: cross-sectional descriptive study that was undertaken at Ghurki Trust Teaching Hospital, Lahore. Methodology: 156 patients aged between 18 and 65 years old and of both sexes, who presented with clinical suspicion of having meniscal injury were selected through non-probability consecutive sampling. Patients who had undergone a knee surgery previously, knee tumor, those who were pregnant, immunocompromised or those who were not willing to participate were excluded. Every patient also received 1.5-Tesla magnetic-resonance-imaging (MRI) of the knee and knee-arthroscopy. The arthroscopic findings were compared with MRI findings. The sensitivity, specificity, PPV, NPV, and diagnostic accuracy were computed with the help of a 2 × 2 contingency table. Result: MRI showed injuries in 103 patients and arthroscopy showed injury in 98 patients. When compared to arthroscopy, MRI had 90 true-positives, 45 true-negatives, 13 false-positives and 8 false-negatives. The sensitivity, specificity, positive predictive value, negative predictive value, and the overall diagnostic accuracy of MRI were 91.84, 77.59, 87.38, 84.91 and 86.54 respectively. Conclusion: MRI was both sensitive and has a good diagnostic accuracy in identifying meniscal injury. It is a convenient non-invasive diagnostic method but arthroscopy still is the gold standard when patients still have persistent symptoms or inconclusive results at imaging