MRI evaluation of meniscal injuries of knee with arthroscopy correlation: A comparative study in a tertiary care hospital

Among various osseous, ligamentous structures around knee meniscus play important role in decreasing load on articular cartilage, smooth movement, reducing friction between opposing articular surfaces of femur, tibia during movement. An accurate diagnosis regarding site, type, grade of meniscal tear along with other associated injury is essential for early operative treatment or non-operative conservative management. This was a descriptive retrospective comparative study to determine the role of MRI in evaluating spectrum and grading of meniscal injuries of knee joint and correlate the findings with arthroscopy. A total of 30 patients clinically suspected of having meniscal injury were evaluated over a period of 1 ½ year from July 2018 to December 2019. Clinical evaluation for meniscal injury with emphasis on medial and lateral joint tenderness, McMurrey test, Appley grinding test were performed by experienced an orthopedician. MRI was performed on 1.5 tesla machine followed by arthroscopy in all patients. Taking arthroscopy as gold standard; sensitivity, specificity, PPV, NPV, accuracy of MRI was determined. In our study, most common meniscal injury was medial meniscal injury (63.3%). Lateral meniscal injury comprised of 33.3%, both menisci were injured in 3.3% of cases. Most common type of tear was longitudinal tear and Grade III tear was most common in both medial and lateral menisci. The sensitivity, specificity, PPV, NPV accuracy of MRI for medial meniscal injury was 94.4%, 83.3%, 89.5%, 90.5%, 90.5%. The sensitivity, specificity, PPV, NPV accuracy of MRI for lateral meniscal injury was 90.0%, 95.0%, 90.0%, 95.0%, 93.3%. There is a good correlation between MRI and arthroscopy findings for meniscal injuries thus supporting MRI as excellent primary non invasive diagnostic tool prior to any invasive arthroscopy.