A comparative study of magnetic resonance imaging and arthroscopy in internal derangement of knee

The purpose of this study is to compare the findings of magnetic resonance imaging with arthroscopy in internal derangements of knee and to assess the sensitivity, specificity and accuracy of magnetic resonance imaging in comparison to arthroscopy. Methods and Materials: Fifty six patients with history of suspected internal derangement of knee were evaluated prospectively with MRI and compared with arthroscopy during a one and half a year period from January 2016 to June 2017 at Katuri Medical College & Hospitals, Chinakondrupadu, Guntur. 1.5 Tesla MRI machine using a closed extremity coil is used. Commonly used sequences in MRI of the knee include Turbo-spin echo (TSE), FFE (Gradient echo) and Short Tau Inversion Recovery (STIR) sequences in Axial, Sagittal and Coronal planes using a slice thickness of 3 mm with a 0.3 mm slice gap. Arthroscopy of the knee with standard anteromedial and anterolateral portals with the patient in supine position done in all the cases. Observations: The diagnostic sensitivity, specificity and accuracy of MRI in detecting cruciate ligament and meniscal injuries as compared to arthroscopy is as follows: Anterior Cruciate Ligament (ACL): 97.29%, 89.47%, 94.64% ; Posterior Cruciate Ligament (PCL): 100%, 100%, 100%; Medial Meniscus (MM): 100%, 93.33%, 98.21% and Lateral Meniscus (LM): 93.10, 92.59, 92.85. Most common lesions found were ACL and Medial Meniscal tears (posterior horn of MM being the most common site). Summary and Conclusion: MRI is a useful non-invasive modality having high sensitivity, specificity and accuracy in diagnosing cruciate ligament and meniscal injuries. MRI should be considered as the first line of investigation in all patients with suspected internal derangements of knee. MRI being easily available and non-invasive is useful as a pre-operative screening modality, thus improves the quality of diagnostic and therapeutic arthroscopies and further reduces the morbidity. Arthroscopy is the gold standard in diagnosing cruciate ligament and meniscal injuries.