ROLE OF MAGNETIC RESONANCE IMAGING IN EVALUATING TRAUMATIC KNEE INJURY AND ASSESSING ITS VARIOUS PATTERNS WITH ARTHROSCOPIC CORRELATION

Abstract

BACKGROUND: Magnetic resonance imaging (MRI) is a completely non-invasive diagnostic modality with no ionizing radiation and plays a vital role in assessment of a wide spectrum of inter derangement of knee. Arthroscopy is highly sensitive and specific procedure in both diagnostic and therapeutic, but is invasive and can cause various complications. This study focus on assessing the role of MRI in evaluating traumatic injuries of knee joint and to compare and correlate MRI findings with arthroscopy findings in ligament and meniscal injuries of the knee. METHODOLOGY: This was a hospital based prospective observational study involving 52 patients with knee injuries, carried out over a period of 18 months who underwent, MRI and arthroscopy of the knee. Patients fulfilling the inclusions criteria underwent MRI performed on SIEMENS® Magnetom Avanto, 1.5 Tesla, 18 channel MRI machine after the MRI scan, findings of the same and diagnosis were recorded. MRI findings of the patients were correlated with arthroscopic findings. Statistical analysis was performed for anterior cruciate and posterior cruciate ligaments, medial meniscus, lateral meniscus and medial & lateral collateral ligaments. MRI results were analysed with Chi-Square test. Sensitivity, specificity, accuracy, positive predictive value (PPV) and negative predictive value (NPV) of MRI is evaluated considering arthroscopy as gold standard of reference. RESULTS: Out of the total 52 cases with knee injury35 were males and 17 were females. Most of the patients were within age group of 36-45 years, road traffic accidents (RTA) and twisting injuries were the most common causes. Anterior cruciate ligament (ACL) tears identified by MRI being the most common at 78.4%, followed by medial meniscus (MM) in 33.3 % cases. Posterior cruciate ligament (PCL) injuries in 17.6%, medial collateral ligament xv i (MCL) injuries occurred in 29.4% of cases, while lateral collateral ligament (LCL) injuries were less common at 11.8%. The ACL has 97.5% sensitivity and 91.7% specificity, while the PCL has 100% sensitivity and high specificity (97.7%). Medial and lateral meniscus injuries have moderate sensitivity (66.7% and 69.2%, respectively) but high specificity (90.3% and 89.7%). Cruciate ligaments (medial and lateral) showed lower sensitivity (66.7% and 60%, respectively) and variable specificity (82.5% and 93.6%, respectively). CONCLUSION: MRI was highly sensitive and accurate at the identification of both ACL and PCL tears as evidenced by close agreement with arthroscopic diagnosis. The diagnostic agreement for the menisci and cruciate ligaments was moderate. Diagnosing articular fractures and specific pattern of bone contusions can guide us to narrow our diagnosis