Relevance of sonological evaluation in medial knee injuries and its comparison with magnetic resonance imaging findings – A prospective study

Abstract

Background: Ultrasonography offers several unique strengths over magnetic resonance imaging (MRI) that makes it a promising technique for the evaluation of certain disorders of the knee. Ultrasonography has higher spatial resolution than MRI, which may be helpful in evaluating the superficial structures and popliteal fossa of the knee in detail. Visualizing the medial collateral ligament (MCL) under ultrasound is relatively easy due to its superficial location, spanning from the medial femoral condyle to the medial tibial metaphysis. Meanwhile, MRI is expensive, not advisable to all due to its claustrophobia and ferromagnetic property. Ultrasound, on the other hand, is an inexpensive, widely available, and non-invasive technique which also allows dynamic imaging. Our objective is to assess the validity of ultrasound in the diagnosis of medial knee injuries in comparison with MRI findings. Materials and Methods: Patients attending the Department of Orthopaedics are referred to the Department of Radiodiagnosis of Government (TD) Medical College, Alappuzha, who were clinically suspected to have medial knee injury, during the study. This study was a prospective study. Prospective patients with clinically suspected medial knee injuries scheduled for MRI of the knee were evaluated by ultrasound examination before the MRI. Sonographic findings were then compared to MRI results. Results and Discussion: Sixty patients were enrolled in the study. 73.3% of the study population were male and most of them belonged in their 2nd and 3rd decades. Most of the injuries were left-sided (60%) and majority (65%) presented for radiological evaluation within 1 week–1 month of history of injury. The accuracy of ultrasound in the diagnosis of MCL and medial meniscus injuries were 86.7% and 85%, respectively. Ultrasonography demonstrated 89.6% sensitivity and 75% specificity for MCL injuries and 85.3% sensitivity and 84.6% specificity for medial meniscus tears. The most frequent knee finding in this study was joint effusion which was seen in 50 (83.3%) of patients. Conclusion: Ultrasonography gives high accuracy and specificity in the detection of MCL and medial meniscal injuries. Ultrasound may have a role as the initial rapid imaging modality in patients with suspected MCL or medial meniscus injuries, and it may serve as an effective low-cost screening tool for patients with medial meniscal or MCL injuries and avoid performing the high-cost MRI.