![torn acl mri torn acl mri](http://uwmsk.org/static/residentprojects/ACLtear.jpg)
Changes in the kinematics of the knee joint leads to an increased stress on the menisci, whereby increased damages to the cartilage can be observed over several years (Logan et al.
![torn acl mri torn acl mri](https://www.hss.edu/images/corporate/intact-acl.jpg)
The loss of function of the ACL causes into an anteromedial joint instability, where the tibial head has increased mobility relative to the thigh. 1995 Stäbler & Freyschmidt 2005 Korn et al. This type of injury results in rupture of the medial collateral ligament, the dorsomedial capsule including the posterior horn of the medial meniscus, and the anterior cruciate ligament (Barry et al. An ACL tear typically includes valgus-flexion, and external rotation. The diagnosis of meniscal injuries, however, was not superior at both flexion positions compared to commonly performed examinations at knee extension.Īnterior cruciate ligament (ACL) tear is currently the most common ligament injury to the knee joint, occurring in as many as 1 in 3,500 individuals each year (Barber-Westin & Noyes 2011). In conclusion, MR Imaging of the knee at 55° of flexion and less at 30° of flexion allows an improved diagnosis of injuries to the anterior cruciate ligament as compared to MRI examinations at extension. During flexion the ligament tension decreased, which causes the anterior cruciate ligament to have cylindrical shape and therefore made visualization of the injury easier. The improved results in the diagnosis of ACL tears in response to 30° flexion and in particular in response to 55° flexion were based on the fact that the anterior cruciate ligament moved further away from the intercondylar roof with increased knee flexion. The diagnosis of meniscal tears was more difficult due to small peripheral tears. MR imaging was only able to diagnose lateral meniscus tears with 55% accuracy in all three knee positions. The accuracy of diagnosing medial meniscus lesions was 73% at extension, 64% at 30° flexion and 73% at 55° of flexion. MRI imaging of complete ACL ruptures resulted in 83% accuracy of diagnosis when imaged at 30° flexion, 93% accuracy at 55° flexion, and 83% accuracy at extension. Partial ACL ruptures were diagnosed with 63% accuracy using MR imaging at 30° and 55° of knee flexion compared to 50% accuracy during knee extension. Additionally, each angle MRI was compared to arthroscopy results. Images were compared between groups and rated as better quality, same quality, or worse quality. Image quality of MRI examinations was evaluated using a three-point rating scale in a blinded fashion. In 29 of 40 patients, arthroscopy results were compared to the MRI examinations. Sagittal T2-weighted TSE sequences were acquired. A standard MR knee coil was used at extension, whereas at 30° and 55° of flexion a non-metallic positioning device and a flexible surface coil was placed ventral to the patella. Knee joints from 40 patients with clinical suspicion of an anterior cruciate ligament (ACL) rupture were examined using MRI while the knee joint was either extended or flexed at 30° and 55° of knee flexion. The aim of the study was to evaluate whether MR Imaging of the knee at 30° and 55° of flexion can improve the diagnosis of anterior cruciate ligament and menisci injuries compared to arthroscopy and imaging during extension of the knee joint.