MRI classification of native articular cartilage delamination within the knee

Transcription

1 MRI classification of native articular cartilage delamination within the knee Poster No.: C-2242 Congress: ECR 2010 Type: Scientific Exhibit Topic: Musculoskeletal Authors: A. I. K. McGow 1, H. Yoshioka 2, A. Watanabe 3, T. Bryant 1, T. Keywords: DOI: Minas 1 ; 1 Boston, MA/US, 2 Orange, CA/US, 3 Ichihara/JP cartilage delamination, knee, MRI /ecr2010/C-2242 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 17

2 Purpose Radiologists rarely describe articular cartilage delamination, defined as a sharply marginated cartilage defect, consistently. 1,2,3,4 Lack of uniform terminology to describe cartilage delamination can result in under-diagnosis, preventing proper treatment (MACT or ACI). Our aim is to classify the MRI appearance of surgically proven native articular cartilage delamination in the knee to create a unifying vocabulary among clinicians and radiologists, allowing appropriate patient evaluation and therapy. Methods and Materials PATIENTS 294 patients (ages 17-51) had one or more autologous cartilage implanation procedures performed from May 2005 to June All knee operative reports (including all arthroscopies and ACIs) in each patient's medical record were retrospectively reviewed and evaluated for the presence of native articular cartilage "delamination," "undermining," and "flaps." Of these 177 patients, 40 individuals (51 cases), diagnosed between May 2000 and April 2009, had one or more accessible MRI(s) within 1 and 14 months of the operative date. Patient Exclusion Criteria: Inaccessible ACI operative reports No knee MRI within 1-14 months of the operative date Inaccessible MRI via our hospital PACS Unclear location of cartilage delamination in the operative description Operative description was unclear if delamination was in native or surgically altered cartilage Page 2 of 17

3 MRI IMAGING Knee MR arthrography protocol (1.5T or 3T) Up to 20ml of intravenous gadolinium (weight based formula) was injected usually minutes (and up to 40 minutes) prior to imaging while the knee was subjected to continuous motion Standard imaging included multiplanar localizers, coronal and axial fluid sensitive sequences (STIR and/or T2), coronal T1w, sagittal T1w, and sagittal PDw (with and/or without fat-saturation) sequences, which were performed with an extremity coil. MRI CLASSIFICATION Cartilage delamination was defined as a sharply marginated articular cartilage defect or flap Two radiologists classified the MR appearance of native knee articular cartilage delamination with consensus into types 1, 2, 3, or 4, depending on the thickness of the delaminated defect or flap -1: no cartilage loss -2: <50% defect -3: >50% defect -4: full thickness defect Additional stratification for a type 1 or 2 lesion was assigned according to the intrasubstance signal morphology -1a: J-shaped flap -1b: T-shaped flap -1c or 2c: undermining with no surface connection -1d: horizontal flap Additional subtypes for type 2, 3, or 4 defects depended on the presence of marginal flaps -2a, 3a, or 4a: marginal flaps present -2b, 3b, or 4b: marginal flaps absent Adjacent cartilage signal heterogeneity was also noted. Page 3 of 17

4 Images for this section: Page 4 of 17

5 Fig. 1: MR Arthrography (MRA) axial PDw image demonstrating type 1a delamination (J-shaped flap without cartilage loss) in the medial patellar facet. Fig. 2: MRA axial T2w image demonstrating type 1b delamination (T-shaped flap without cartilage loss) in the median ridge of the patella. Page 5 of 17

6 Fig. 3: MRA sagittal PDw image demonstrating type 1c delamination (undermining with no apparent surface connection and no cartilage loss) in the trochlea. Page 6 of 17

7 Fig. 4: MRA axial T2w image demonstrating type 2a delamination. Page 7 of 17

8 Fig. 5: MRA sagittal PDw image demonstrating a type 3 lesion (>50% defect) in the patella and a type 4 lesion (full thickness defect) in the trochlea. Page 8 of 17

9 Results Table 1. Cartilage Delamination Site within the Knee Delamination Site Number of cases % of cases MFC 9 18 LFC 4 8 LTP 6 12 MTP 1 2 Trochlea Patella Table 2. Sex Distribution of Cartilage Delamination Sex Number of cases % of cases Number of patients Male Female % of patients Table 3. Laterality of Cartilage Delamination Knee Number of cases % of cases Right Left Table 4. Types of Cartilage Delamination Types of Delamination Number of cases % of Cases 1a b c 4 8 Page 9 of 17

10 1d 3 6 2a b 1 2 2c 3 6 3a b 0 0 4a b 1 2 ASSOCIATED RESULTS Adjacent signal heterogeneity: 35% (18 cases) No associated heterogeneity: 51% (26 cases) No MR correlate: 14% (7 cases) Complex injury: 4% (2 cases) Images for this section: Page 10 of 17

11 Fig. 1: MR Arthrography (MRA) axial PDw image demonstrating type 1a delamination (J-shaped flap without cartilage loss) in the medial patellar facet. Page 11 of 17

12 Fig. 2: MRA axial T2w image demonstrating type 1b delamination (T-shaped flap without cartilage loss) in the median ridge of the patella. Page 12 of 17

13 Fig. 3: MRA axial T2w image demonstrating type 2a delamination. Page 13 of 17

14 Fig. 4: MRA sagittal PDw image demonstrating type 1c delamination (undermining with no apparent surface connection and no cartilage loss) in the trochlea. Page 14 of 17

15 Fig. 5: MRA sagittal PDw image demonstrating a type 3 lesion (>50% defect) in the patella and a type 4 lesion (full thickness defect) in the trochlea. Page 15 of 17

16 Conclusion Type 1 cartilage delamination where flaps are present without cartilage loss is most common (35% of all cases). MRI may be nondiagnostic, failing to demonstrate surgically proven delamination in 14% of cases. Delamination with adjacent flaps is more common than defects without associated flaps; adjacent signal heterogeneity is also frequent and both may lead to increased size (surface area) of the delaminated cartilage defect. Further investigation is required to determine if cartilage delamination progresses from type 1 through type 4, with increasing thickness of cartilage loss. Cartilage delamination of the patella and trochlea in the right knee are most common, supporting the acute or chronic shearing mechanism in right-knee dominant patients. 1 Classification of the MRI appearance of surgically proven cartilage delamination establishes a common terminology among radiologists and surgeons and will hopefully allow improved detection of cartilage flaps and appropriate treatment. References 1. Kendell SD, Helms CA, Rampton JW, Garrett WE, Higgins LD. MRI appearance of chondral delamination injuries of the knee. Am J Roentgenol. 2005;184: Zaragoza E, Lattanzio PJ, Beaule PE. Magnetic resonance imaging with gadolinium arthrography to assess acetabular cartilage delamination. Hip Int. 2009;19: Anderson LA, Peters CL, Park BB, Stoddard GJ, Erickson JA, Crim JR. Acetabular cartilage delamination in femoroacetabular impingement. Risk factors and magnetic resonance imaging diagnosis. J Bone Joint Surg Am. 2009;91: Pfirrman CW, Duc SR, Zanetti M, Dora C, Hodler J. MR arthrography of acetabular cartilage delamination in femoroacetabular cam impingement. Radiology. 2008;249: Page 16 of 17

17 Personal Information Anna I. K. McGow, MD Department of Radiology Brigham and Women's Hospital Harvard Medical School Affiliate 75 Francis Street Boston, MA USA Page 17 of 17