COMPARISON OF CLINICAL, MAGNETIC RESONANCE IMAGING (MRI) AND ARTHROSCOPIC FINDINGS IN ASSESSMENT OF CARTILAGE DEFECTS AND INTERNAL DERANGEMENT OF KNEE

Abstract

Background: Knee is the most commonly injured joint because of its anatomical structure, its exposure to external forces, and its functional demands. Ligament injuries are among common injuries occurring in knee due to contact sporting events. Although arthroscopy is considered gold standard for diagnosing ligament injuries and cartilage defects, magnetic resonance imaging (MRI) is considered non-invasive investigation of choice in diagnosing them. There have been literature studies comparing magnetic resonance imaging findings with that of arthroscopy. Orthopaedic surgeons previously relied on clinical evaluation for diagnosing any internal derangement of knee joint. With advent of new clinical methods for diagnosing ligament injuries and cartilage defects, there are very less studies comparing accuracy of all three methods, clinical examination, magnetic resonance imaging and arthroscopy to reach a definitive diagnosis. This study aims to compare the sensitivity, specificity, accuracy and predictive values of clinical examination and magnetic resonance imaging with that of arthroscopy which is the gold standard investigation of choice for cartilage defects and internal derangement of knee. Material and Methods: A prospective, observational and hospital-based study conducted in Kolar, on patients with internal derangement of knee and cartilage defects. Clinical examination, magnetic resonance imaging and arthroscopy were done on all patients, the findings of which were compared using Chi square test. Accuracy, sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) were evaluated considering arthroscopy as standard of reference. xxi Results: Anterior cruciate ligament (ACL) was most common ligament to be injured followed by the medial meniscus. Overall accuracy of clinical evaluation and magnetic resonance imaging to diagnose meniscal injuries was found to be 94% and 91% respectively. Clinical examination had sensitivity and specificity of 96% and 82% in diagnosing anterior cruciate ligament tears, respectively, whereas magnetic resonance imaging had sensitivity and specificity of 88% and 76% respectively. For medial meniscus, clinical examination had sensitivity and specificity of 93% and 96% respectively whereas magnetic resonance imaging had sensitivity of 100% and specificity of 89%. We observed that accuracy of magnetic resonance imaging for grading anterior cruciate ligament and meniscal tears was similar i.e. 79% and 78% respectively, but was slightly low (70%) for grading of chondromalacia patellae. Conclusion: The study supports both clinical evaluation and MRI in diagnosing internal derangement of knee and chondral defects. Clinical tests are reliable and have high sensitivity in diagnosing ACL tears and chondral defects when compared to MRI. The routine use of MRI for confirmation of diagnosis is not indicated for all lesions and should be done only for select cases. MRI is less reliable in grading anterior cruciate ligament tears, meniscal tears and chondral injuries.