Comparison of magnetic resonance imaging with operative findings in acute traumatic dislocations of the adult knee

Objectives: To compare magnetic resonance imaging (MRI) with examination un der anesthesia and with surgical findings in evaluating soft tissue injurie s in acute traumatic knee dislocations in adults. Design: Retrospective analysis. Setting: Level I trauma center. Patients: For a single surgeon, all patients who underwent MRI before surgi cal treatment for knee dislocations (ten individuals). Intervention: Incompetent ligaments were repaired or reconstructed. Main Outcome Measurements: MRI of knee dislocations was compared with clini cal examination under anesthesia and with intraoperative findings at arthro tomy in ten cases. Pertinent positive and negative findings were recorded, and accuracy, sensitivity, specificity, and positive and negative predictiv e values were calculated. Results: Two mid-grade sprains of the anterior cruciate ligament were erron eously read as complete tears. One rupture or avulsion of each the biceps t endon, the lateral collateral ligament, and the posterolateral and posterom edial corners were considered intact on MRI. The MRI studies erroneously id entified rears of the lateral collateral ligament and medial meniscus in on e case each. Otherwise, the study was highly accurate. Conclusions: MRI is useful for defining the presence of ligamentous injurie s in knee dislocations; however, clinical examination under anesthesia is m ore accurate.