A PROSPECTIVE CROSS-SECTIONAL STUDY ON MRI EVALUATION OF INTERNAL DERANGEMENTS OF THE KNEE JOINT

Introduction: Internal derangements of knee joint constitute a major source of morbidity in patients attending orthopaedic outpatients department of our hospital. It includes a group of disorders due to disruption of normal functioning of ligaments and menisci of knee joint leading to persistent or intermittent signs and symptoms such as pain, instability, or abnormal mobility of the knee. MRI would be a noninvasive, nonoperator dependent effective modality for early detection of these pathologies and has very high negative predictive value. Material and Methods: The study was carried out over a period of one year from April 2018 to April 2019. Fifty patients with clinically suspected internal derangement of knee were included in this prospective study. They were evaluated with detailed clinical history and clinical examinations and were subsequently subjected to imaging of knee using 1.5 T HDxt 8 Channel GE MRI machine. Results: ACL was the commonest ligament to be injured with partial tear being more common than complete tear. MCL was the commonest ligament to be torn in association with ACL. Indirect signs of ACL injury were evaluated and helped to corroborate the tears. Meniscal injury was common in medial meniscus and predominantly involved the posterior horn. In lateral meniscus anterior horn was involved more than posterior horn. In both the meniscus horizontal tear was the most common. Certain pattern of associations of injuries was found such as ACL tear with posterolateral corner injury. Interpretation and Conclusion: MR is an excellent tool for evaluation of ligaments, menisci and osseous structures of knee joint. Various clinical tests and appropriate clinical history complements MR examination. Similarly MR imaging of knee complements therapeutic arthroscopies and would greatly reduce the need of diagnostic arthroscopies. Thus MR is a non-invasive, painless and morbidity-free modality for accurate preoperative assessment that is well accepted by patients.

MR imaging of meniscal tears

Background: Menisci transmit the forces across the joint and cushion the mechanical loading of the joint. Thus, it is important to identify meniscal tear. A thorough understanding of normal meniscal anatomy and surrounding structure is critical for diagnosis. Magnetic resonance imaging is the current modality of choice providing fine resolution and multi-planar imaging for identifying the meniscal injuries and the various pattern of tear, helping to plan the subsequent management. The purpose of the work was to study the role of MRI in classifying the meniscal injuries.Methods: MRI Knee of 136 patients with meniscal injuries was studied. All the MR imaging scans were performed on 1.5-T MR system (Siemens magnetom Essenza).Results: A total of 136 patients were studied in which majority of the patient’s i.e. 90.44 % had medial meniscal tear while 18.38 % patients had lateral meniscal tear. Both medial and lateral meniscal tears were found in 8.82 % patients. Among the different types of tears, horizontal tear was the most common tear in both medial and lateral meniscus comprising 52.8 % and 52 % respectively. The tears being most common in the age group 41-50years. There were associated injuries to the other ligaments of the knee joint along with meniscal tear, ACL tear being the most common and was seen in 50% of patients.Conclusions: MRI is a good modality for classifying meniscal injury and evaluation of injuries to the associated ligaments. Secondary signs are good predictors of underlying meniscal tear in equivocal cases.