Magnetic Resonance Imaging of the Knee Injuries and Its Correlation with Arthroscopy: A Prospective Study

Abstract

Background: Knee trauma may cause injury to menisci, cartilages, cruciate ligaments or bones. Immediately after injury joint effusion may also develop and it is very difficult to clinically judge the extent of damage caused to the knee. Plain radiography though can diagnose fractures it is not sensitive or reliable in detecting meniscal tears and ligament injuries. Magnetic resonance imaging of the knee joint has revolutionized the way we treat the knee injuries. MRI allows excellent soft-tissue details with multiplanar imaging capability that gives accurate evaluation of extra-and intra-articular structures of the knee not demonstrated with other imaging modalities. Advantages of MRI over other imaging modalities include lack of radiation, lack of beam hardening artefacts, excellent soft tissue contrast and multi planar imaging capabilities.MRI moreover is non invasive and do not require manipulation of knee as in arthrogram. Aims: (1) To study the occurrence of ligament and meniscal injuries following knee trauma. (2) To analyze type and grade of the ligament injuries with the help of appearances on MRI study. (3) To correlate the MRI findings with the arthroscopic findings in selected patients. (4) To study the limitations and pitfalls of MRI in detecting the ligament injuries of knee. Methods: This study was a prospective clinico-radiological study of 97 patients with knee injuries conducted at radiology department of a tertiary care medical college located in an urban area. The duration of the study was 18 months. Patients presenting with suspected internal derangement of knee following trauma were included in this study. MRI of knee was done in all cases. T1 & PD weighted sequences in sagittal and coronal planes, T2-weighted in axial, coronal and sagittal planes were done in all patients. Fat suppressed T2 or STIR sequences were done wherever indicated. Arthroscopy was done in selected cases. The findings of MRI and arthroscopy were correlated. Results: The study comprised of 97 patients with knee injury in whom ligament or meniscal Injuries leading to internal derangement of knee were suspected. Out of 97 patients 60 (61.85%) were males and 37 (38.14) were females with a M: F ratio of 1: 0.61. In males most common affected age group was found to be 21-30 years (38.33%) while in females it was more than 40 years (35.13%) of age. Joint effusion was present in 57 (58.76%) patients. ACL tear was present 36 (37.11%) patients, in 10 patients the tear was partial while in remaining 26 patients the tear was complete. Complete and Partial PCL tear was present in 1 and 2 patients respectively. MCL tear was present in 25 cases (25.77%). MCL tear was grade I, II and III in 16, 4 and 5 patients. LCL tear was seen in 10 patients out of which 6 were Grade I followed by Grade II and Grade III in 2 patients each. Medial meniscus was injured in 58 patients (59.79%) and lateral meniscus was injured in 10 patients. Osseous and other injuries were present in 48 patients (49.48%). Arthroscopy was done in 23 (23.71) pat...