Feasibility of point-of-care knee ultrasonography for diagnosing anterior cruciate and posterior cruciate ligament tears in the ED

Objective: To evaluate the feasibility of point-of-care knee ultrasonography (POCUS) compared with knee magnetic resonance imaging (MRI) for diagnosing anterior cruciate ligament (ACL) and posterior cruciate ligament (PCL) tears in patients with acute knee trauma. Material and methods: A prospective study was conducted in a tertiary hospital emergency department; acute (within 1-week) knee trauma patients with suspected ACL or PCL tear were recruited. Two POCUS performers (a board-certified emergency physician and a musculoskeletal radiologist) independently evaluated the ACL and PCL using POCUS. Findings were classified as normal appearance or ligament tear. Final radiology reports of knee MRI were used as the reference standard. We calculated the diagnostic values (sensitivity, specificity, and accuracy) for POCUS obtained by both POCUS performers. Kappa values (k) were calculated for inter-observer agreement between the two POCUS performers. Results: Sixty-two patients were enrolled. Compared with the reference standard, POCUS showed acceptable sensitivity (90.6–100%), specificity (90.0–97.7%), and accuracy (91.9–96.8%). Inter-observer agreement between the two POCUS performers was excellent (k = 0.853–0.903). Conclusion: POCUS demonstrates excellent precision as compared to MRI in the diagnosis of ACL and PCL tears. The findings of POCUS could be used for immediate diagnosis and further pre-operative imaging in patients with acute knee trauma.