Get access

Assessment of tissue repair in full thickness chondral defects in the rabbit using magnetic resonance imaging transverse relaxation measurements

Authors

  • Sharan Ramaswamy,

    1. National Institute on Aging, National Institutes of Health, Laboratory of Clinical Investigation, Gerontology Research Center, Room 4D-08, 5600 Nathan Shock Drive, Baltimore, Maryland 21224
    Search for more papers by this author
  • Ilksen Gurkan,

    1. Department of Orthopedic Surgery, Johns Hopkins University School of Medicine, Baltimore, Maryland 21287
    Search for more papers by this author
  • Blanka Sharma,

    1. Department of Biomedical Engineering, Johns Hopkins University, Baltimore, Maryland 21218
    Search for more papers by this author
  • Brett Cascio,

    1. Department of Orthopedic Surgery, Johns Hopkins University School of Medicine, Baltimore, Maryland 21287
    Search for more papers by this author
  • Kenneth W. Fishbein,

    1. National Institute on Aging, National Institutes of Health, Laboratory of Clinical Investigation, Gerontology Research Center, Room 4D-08, 5600 Nathan Shock Drive, Baltimore, Maryland 21224
    Search for more papers by this author
  • Richard G. Spencer

    Corresponding author
    1. National Institute on Aging, National Institutes of Health, Laboratory of Clinical Investigation, Gerontology Research Center, Room 4D-08, 5600 Nathan Shock Drive, Baltimore, Maryland 21224
    • National Institute on Aging, National Institutes of Health, Laboratory of Clinical Investigation, Gerontology Research Center, Room 4D-08, 5600 Nathan Shock Drive, Baltimore, Maryland 21224
    Search for more papers by this author

  • This article is a US Government work and, as such, is in the public domain in the United States of America.

Abstract

The purpose of this study was to determine if the noninvasive and nondestructive technique of magnetic resonance imaging could be used to quantify the amount of repair tissue that fills surgically-induced chondral defects in the rabbit. Sixteen 4-mm diameter full-thickness chondral defects were created. A photopolymerizable hydrogel was used to seal the defects as a treatment modality. At 5 weeks, the animals were sacrificed and the distal femur was subjected to MRI analyses at high field (9.4 T). The transverse relaxation time (T2) in each defect was measured. Histology and histomorphometric analysis were used to quantify the amount of repair tissue that filled each defect. The relationship between T2 and percent tissue fill was found to fit well to a negatively sloped, linear model. The linear (Pearson's product-moment) correlation coefficient was found to be r = −0.82 and the associated coefficient of determination was r2 = 0.67. This correlation suggests that the MRI parameter T2 can be used to track changes in the amount of repair tissue that fills cartilage defects. This would be especially useful in in vivo cartilage tissue engineering studies that attempt to determine optimal biomaterials for scaffold design. Published 2007 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2008

Ancillary