Sheen-Woo Lee MD, Abstract Co-Author: Nothing to Disclose

Su Joa Ahn, Presenter: Nothing to Disclose

Dae Hong Park, Abstract Co-Author: Nothing to Disclose

Yu Mi Jeong MD, Abstract Co-Author: Nothing to Disclose

Yun Mi Hwang MD, Abstract Co-Author: Nothing to Disclose

Jae Ang Sim MD,PHD, Abstract Co-Author: Nothing to Disclose

To analyze the incidence of posterolateral corner (PLC) lesions on three-dimensional isotropic SPACE MRI of knee in patients with confirmed posterolateral rotatory instability.

We retrospectively reviewed forty-five patients with knee MRI on 3.0T, who underwent PLC reconstruction (N=20) or were positive on physical examination (N=25). Three-dimensional isotropic proton density SPACE images were evaluated for thickening or avulsion of PLC structure proper (popliteofibular, fabellofibular, arcuate ligaments, popliteomeniscal fascicle), and compared with normal knee (N=20). Lateral collateral ligament-biceps femoris, popliteus tendon, cruciate ligaments, and anteromedial tibial rim fracture, proximal tibiofibular joint congruity, edema between popliteus and lateral gastrocnemius were also evaluated. Mann-Whitney U test was used for statistical analysis.

3D-SPACE MRI of operated group revealed lesions in popliteofibular ligament in 15(75%), fabellofibular ligament in 3(15%), arcuate ligament in 9(45%), popliteomeniscal fascicle in 5(25%). Conservative-management group showed lesions in 25(100%), 15(60%), 16(64%), 13(52%), respectively. Lateral collateral ligament-biceps femoris, popliteus tendon, cruciate ligaments, and anteromedial tibial rim fracture, proximal tibiofibular joint congruity, edema between popliteus and lateral gastrocnemius were noted in 14(70%), 14(70%), 17(85%), 0(0%),10(50%), 14(70%) in operative, and 19(76%), 18(72%), 15(60%), 1(4%),12(48%), 13(52%) in conservative-treatment groups, respectively. Compared to operated group, conservative-treatment group showed significantly higher incidence of lesions in cruciate and fabellofibular ligaments, and combined trauma in major organs such as brain or abdomen (p<0.05). Compared to control, the MRI of total PLC-positive patients showed significantly higher incidence of lesions in all PLC structure proper (p<0.05).

Abnormality of PLC proper and the patterns of injury are well visualized on 3T knee MRI with 3D-SPACE in patients with posterolateral rotatory instability.

Occult PLC injury can result in ACL/PCL reconstruction failure and chronic posterolateral instability.The MRI findings may help plan the treatment of knee injury when not clinically suspected.

Lee, S, Ahn, S, Park, D, Jeong, Y, Hwang, Y, Sim, J, MRI Findings of Posterolateral Corner Injury on Three-dimensional Isotropic SPACE.  Radiological Society of North America 2012 Scientific Assembly and Annual Meeting, November 25 - November 30, 2012 ,Chicago IL. http://archive.rsna.org/2012/12031399.html