MRI Findings of Posterolateral Corner Injury on Threedimensional

Transcription

1 MRI Findings of Posterolateral Corner Injury on Threedimensional Isotropic SPACE. Poster No.: C-1792 Congress: ECR 2013 Type: Scientific Exhibit Authors: S.-W. Lee, Y. M. Jeong, J. A. Sim, S. Ahn; Incheon/KR Keywords: Trauma, Decision analysis, MR, Musculoskeletal joint DOI: /ecr2013/C-1792 Any information contained in this pdf file is automatically generated from digital material submitted to EPOS by third parties in the form of scientific presentations. References to any names, marks, products, or services of third parties or hypertext links to thirdparty sites or information are provided solely as a convenience to you and do not in any way constitute or imply ECR's endorsement, sponsorship or recommendation of the third party, information, product or service. ECR is not responsible for the content of these pages and does not make any representations regarding the content or accuracy of material in this file. As per copyright regulations, any unauthorised use of the material or parts thereof as well as commercial reproduction or multiple distribution by any traditional or electronically based reproduction/publication method ist strictly prohibited. You agree to defend, indemnify, and hold ECR harmless from and against any and all claims, damages, costs, and expenses, including attorneys' fees, arising from or related to your use of these pages. Please note: Links to movies, ppt slideshows and any other multimedia files are not available in the pdf version of presentations. Page 1 of 10

2 Purpose The structures of the posterolateral corner (PLC) include popliteofibular, fabellofibular, arcuate ligaments, and popliteomeniscal fascicle. They are responsible for posterolateral stabilization of the knee. The PLC structures are not well visualized on routine two-dimensional sequences. Their injury often accompanies cruciate ligament injury ; if they go unrecognized, less favorable outcome in cruciate ligament repair may result. The purpose of this article is to use a thin section isotropic three-dimensional (3D) SPACE sequence to find the pathologic appearance the posterolateral corner (PLC) injury in patients with confirmed posterolateral rotatory instability Images for this section: Page 2 of 10

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4 Fig. 1: Lateral and posterior view of knee illustrates the insertion of iliotibial band (1), capsular ligament (2), lateral collateral ligament (3), fabellofibular ligament (4), and popliteus muscle and tendon (5) (Haims AH et al, American Journal of Roentgenology 2003) Page 4 of 10

5 Methods and Materials We retrospectively reviewed patients who underwent PLC reconstruction (N=17), and those who were physical examination-positive but conservatively managed (N=8). MRI of the patients with prospective reports of PLC lesion and negative clinical finding (N=24), and those of normal knee (N=21), were reviewed as control. 3D isotropic proton density SPACE images of the knee taken on 3T scanner (slice thickness 0.5 mm, TR 1300s, TE 38s, FOV 150X150mm, matrix 320X276) were evaluated for the thickening or avulsion of PLC structure proper (popliteofibular, fabellofibular, arcuate ligaments, popliteomeniscal fascicle). Lateral collateral ligament, popliteus, cruciate ligaments, proximal tibiofibular joint incongruity, edema between popliteus and lateral gastrocnemius, and edema of common peroneal nerve were also evaluated. Findings on 2D images were compared. Mann-Whitney U test was used for statistical analysis. PLC proper (PFL, FFL, AL, PMF) Grade I Nonvisualization Normal Grade II Normal thin structure without discontinuity LCL, Popliteus tendon, Cruciate ligaments Sprain (Increased SI) Grade III Thickening and/or avulsion Partial thickness tear Grade IV Table 1 Masking of the PLC due to severe surrounding edema Full thickness tear Results 3D-SPACE MRI of operated group revealed lesions in popliteofibular ligament in 12(71%), fabellofibular ligament in 2(12%), arcuate ligament in 8(47%), popliteomeniscal fascicle in 5(29%). Conservative-management group showed lesions in 5(63%), 3(38%), 5(63%), 4(50%), respectively. Lateral collateral ligament, popliteus, cruciate ligaments, proximal tibiofibular joint incongruity, edema between popliteus and lateral gastrocnemius, common peroneal nerve edema were noted in 11(65%), 14(82%), 15(88%), 8(47%), 12(71%), 7 (41%) in operative, and 5(63%), 6(75%), 7(88%), 6(75%), 4(50%), 6 (75%) in conservative-treatment groups, respectively. Compared to the false positive group, the injured group showed higher incidence of popliteofibular and arcuate Page 5 of 10

6 ligament lesions, but not statistically significant. The lesions of PLC proper were visible in true positive patients and not in normal patients. There were different composition of grades of the lesions between 2D routine image and 3D-SPACE imgae Most of PLC proper structures show higher incidence of grade II and grade III lesions on 3D isotropic space image, and higher grade IV lesions on 2D. Images for this section: Fig. 2: Oblique coronal reformatted image of popliteofibular ligament by 3D SPACE sequence. On the left is grade II (normal), and on the right is grade III (thickening) Page 6 of 10

7 Fig. 4: Oblique reformatted image of arcuate ligament on 3D SPACE. On the left is grade II, and on the right is grade III. Fig. 5: Oblique reformatted image of popliteomeniscal fascicle on 3D SPACE. On the left is grade II, and on the right is grade III. Page 7 of 10

8 Fig. 6: 2D proton-density coronal image (left) and oblique reformatted 3D SPACE image (right) of popliteofibular ligament. The ligament thickening is visible on 3D SPACE (slice thickness 0.5 mm), whereas it is masked by surrounding edema on 2D (slice thickness 4 mm). Fig. 3: Oblique reformatted image of fabellofibular ligament on 3D SPACE. On the left is grade II, and on the right is grade IV (masking due to severe surrounding edema). Page 8 of 10

9 Conclusion Abnormality of PLC proper and the patterns of injury are well visualized on 3T knee MRI with 3D-SPACE. The PLC lesions on 3D SPACE, combined with major ligament injury of the knee, may predict posterolateral rotatory instability. References Larsen, M.W. and A. Toth, Examination of posterolateral corner injuries. J Knee Surg, (2): p Vinson, E.N. and C.A. Helms, Imaging for evaluation of posterolateral corner injury. J Knee Surg, (2): p Ross, G., et al., Evaluation and treatment of acute posterolateral corner/anterior cruciate ligament injuries of the knee. J Bone Joint Surg Am, A Suppl 2: p Recondo, J.A., et al., Lateral stabilizing structures of the knee: functional anatomy and injuries assessed with MR imaging. Radiographics, Spec No: p. S91-S102. Malone, A.A., G.S. Dowd, and A. Saifuddin, Injuries of the posterior cruciate ligament and posterolateral corner of the knee. Injury, (6): p Harish, S., et al., Imaging of the posterolateral corner of the knee. Clin Radiol, (6): p Davies, H., A. Unwin, and P. Aichroth, The posterolateral corner of the knee. Anatomy, biomechanics and management of injuries. Injury, (1): p Lee, J., et al., Arcuate sign of posterolateral knee injuries: anatomic, radiographic, and MR imaging data related to patterns of injury. Skeletal Radiol, (11): p Cooper, J.M., P.T. McAndrews, and R.F. LaPrade, Posterolateral corner injuries of the knee: anatomy, diagnosis, and treatment. Sports Med Arthrosc, (4): p Malone, W.J. and G. Koulouris, MRI of the posterolateral corner of the knee: normal appearance and patterns of injury. Semin Musculoskelet Radiol, (3): p Yu, J.S., et al., Posterolateral aspect of the knee: improved MR imaging with a coronal oblique technique. Radiology, (1): p Page 9 of 10

10 LaPrade, R.F., et al., The magnetic resonance imaging appearance of individual structures of the posterolateral knee. A prospective study of normal knees and knees with surgically verified grade III injuries. Am J Sports Med, (2): p Rajeswaran, G., J.C. Lee, and J.C. Healy, MRI of the popliteofibular ligament: isotropic 3D WE-DESS versus coronal oblique fat-suppressed T2W MRI. Skeletal Radiol, (12): p Personal Information Dr. Sheen-Woo Lee MD., PhD. Department of Radiology, Gachon University Gil Hospital, Incheon, South Korea ; leesw1@gmail.com Yu Mi Jeong MD. Department of Radiology, Gachon University Gil Hospital, Incheon, South Korea ; youme34@gilhospital.com Jae Ang Sim MD., PhD. Department of Orthopedic surgery, Gachon University Gil Hospital, Incheon, South Korea ; sim_ja@gilhospital.com Sujoa Ahn MD. Department of Radiology, Gachon University Gil Hospital, Incheon, South Korea. Page 10 of 10