Functional Ultrasonography in Diagnosing Anterior Cruciate Ligament Injury as Compared to Magnetic Resonance Imaging

BACKGROUND: Magnetic resonance imaging (MRI) has been gold standard investigation for diagnosing anterior cruciate ligament (ACL) tear. Availability and cost are two main factors limiting the universal use of MRI in all those patients in whom ligament injury is suspected. We compared the outcome of functional USG with gold standard MRI scan in this prospective study. MATERIALS AND METHODS: In this study, we included the patients coming to orthopedics outpatient department with sign and symptoms of ACL injury. We performed functional USG of the injured and uninjured knee and noted the difference in translation, measured by USG. More than 1 mm of difference in translation of tibia on the affected side as compared to uninjured side is taken as significant. We compared our result with the findings of MRI. The study result of 130 patients revealed high sensitivity (81.65%) and high specificity (89%) in diagnosing ACL injury. The positive predictive value of the test was 97.8%, and the negative predictive value was 44%. The P value of the difference of translation as 0.0001 was also statistically significant. CONCLUSIONS: We can safely conclude from the study that the functional USG can be used as a primary tool to diagnose ACL tears. USG's ubiquitous availability and simple technique of the procedure can bring a revolution in the future for diagnosing and managing ACL injury.