MRI Diagnosis Of Tears Of Knee Anterior Cruciate Ligament

Object: To investigate the value of MR imaging in diagnosis of tears of the anterior cruciate ligament(ACL) of the knee and look for methods to further improve diagnosis accuracy. Methods: 44 patients who had been highly suspected internal derangement of the knee was performed both MRI and arthroscopy examination. The MR images were prospectively interpreted and analyzed for accuracy of MR diagnosis of ACL tears. The posterior cruciate ligament (PCL)line, angle and PCL curvature index were measured in all patients Result: 23 patients with ACL tears and 21 patients with ACL normal confirmed by arthroscopy.2 partial tears and 21 complete tears in all of ACL tears . The sensitivity, specificity ,accuracy, positive predictive value and negative predictive value of MR diagnosis of ACL tears were 95.7%, 85.7%, 90.9%,88.5% and 94.7%,respectively .tients with positive PCL line in 19 ACL tears and 1 patients with positive PCL line in 20ACL normal, The sensitivity, specificity, accuracy, positive predictive value and negative predictive value of positive PCL line in detecting the tear of ACL were 78.9%,95.0%, 90.9% 93.8%, 87.2%. The PCL angle in tear ACL was(100±5.9) ° , While in normal ACL (120±8 .9) °(p< 0.05).The PCL index in tear ACL was 2.64± 0.27 ,while in normal ACL 3.12±0.31 (p < 0.05). Conclusion: MR imaging is an effective tool in the detection of ACL tears. But the accuracy of MR imaging for diagnosis of chronic or Partial tear of anterior cruciate ligament tears were decreased. The high specificity of the positive PCL line support the diagnosis of ACL tear. The smaller of the PCL angle and the PCL index, the more possibility of ACL tears.