Double PCL sign on sagittal MRI of the knee

A 24-year-old male presented with left knee pain and swelling after a fall six weeks earlier playing football. Clinical examination revealed an antalgic gait and a moderate left knee effusion with tenderness along the medial joint line. Anterior drawer and Lachman tests were positive, suggesting an anterior cruciate ligament (ACL) injury. An MRI scan performed shortly after the injury revealed a large joint effusion and significant acute bone oedema involving the medial tibial condyle. While the posterior cruciate ligament (PCL) was intact, the ACL was elongated and suspicious for an intrasubstance tear. …