The uncertainty of predicting intact anterior cruciate ligament degeneration in terms of structural properties using T(2)(*) relaxometry in a human cadaveric model.
The combination of healing anterior cruciate ligament (ACL) volume and the distributions of T2(*) relaxation times within it have been shown to predict the biomechanical failure properties in a porcine model. This MR-based prediction model has not yet been used to assess ligament degeneration in the aging human knee. Using a set of 15 human cadaveric knees of varying ages, we obtained in situ MR measures of volume and T2(*) of the intact ACL and then related these MR variables to biomechanical outcomes (maximum and yield loads, linear stiffness) obtained via ex vivo failure testing. Using volume in conjunction with the median T2(*) value, the multiple linear regression model did not predict maximum failure load for the intact human ACL; R(2)=0.23, p=0.200. Similar insignificant results were found for yield load and linear stiffness. Naturally restricted distributions of the intact ligament volume and T2(*) (demonstrated by the respective Z-scores) in an older cadaveric population were the likely reason for the insignificant results. These restricted distributions may negatively affect the ability to detect a correlation when one exists. Further research is necessary to understand the relationship of MRI variables and ligament degeneration. While this study failed to find a significant prediction of human biomechanical outcome using these MR variables, with further research, an MR-based approach may offer a tool to longitudinally assess changes in cruciate ligament degradation.
Department of Orthopaedics, Warren Alpert Medical School, Brown University/Rhode Island Hospital, Providence, RI, USA; Center for Biomedical Engineering and School of Engineering, Brown University, Providence, RI, USA.
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Biercevicz
Department of Orthopaedics, Warren Alpert Medical School, Brown University/Rhode Island Hospital, Providence, RI, USA.
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Akelman
Department of Orthopaedics, Warren Alpert Medical School, Brown University/Rhode Island Hospital, Providence, RI, USA.
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Rubin
Department of Neuroscience, Division of Biology and Medicine, Brown University, Providence, RI, USA.
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Walsh
Center for Biomedical Engineering and School of Engineering, Brown University, Providence, RI, USA; Department of Diagnostic Imaging, Warren Alpert Medical School of Brown University/Rhode Island Hospital, Providence, RI, USA.
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Merck
Department of Orthopaedics, Warren Alpert Medical School, Brown University/Rhode Island Hospital, Providence, RI, USA; Center for Biomedical Engineering and School of Engineering, Brown University, Providence, RI, USA. Electronic address: Braden_Fleming@brown.edu.
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Fleming
D000328:Adult; D000368:Aged; D000818:Animals; D016118:Anterior Cruciate Ligament / Q000473:pathology / Q000503:physiopathology*; D001696:Biomechanical Phenomena; D005260:Female; D006801:Humans; D007592:Joint Diseases / Q000175:diagnosis* / Q000503:physiopathology; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009929:Organ Size; D014945:Wound Healing; D055815:Young Adult
Age; Degeneration; Intact ACL; Structural properties; relaxation time