In vivo evaluation of the stiffness of the patellar tendon Public Deposited

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  • March 21, 2019
  • Liu, Hsin-Yi
    • Affiliation: School of Medicine, Department of Allied Health Sciences, Curriculum in Human Movement Science
  • Tendon problems are common among athletes as well as the general population. The success of current repair and rehabilitation protocols remains controversial due to the subjective content of the clinical recovery measurements. Tendon mechanical properties have been considered the "gold standard" in evaluating the healing of tendon, but these measures have not been convenient to record in vivo due to the invasive nature of conventional mechanical testing. Recently, an in vivo ultrasonography technique has been successfully applied to detect the change in tendon mechanical properties over time. The overall objective of this study was to assess the capability of this technique to track the change of stiffness in the healing patellar tendon. Initially, a single-scan ultrasound method was used to detect the change in the mechanical properties of patellar tendon in patients with patellofemoral pain syndrome. Our results showed the single-scan method was able detect the change in stiffnes due to this condition. However, the limitation of this method was that movement of the distal insertion of the tendon was unaccounted for. Therefore, we subsequently developed a two-scan method to monitor both insertion sites of the tendon and compared the between-day reliability of this method with the single-scan method. The results showed the deformation of the patellar tendon at the tibial insertion had a significant effect on the total tendon deformation and the two-scan method had higher reliability across time. Therefore, in the last study, we proceeded with the two-scan method to evaluate the stiffness of the healing patellar tendon after ACL reconstruction with a patellar tendon autograft. The result of this study did not show a significant increase in tendon stiffness properties over the 2 to 6 months after surgery, suggesting a longer healing time may be needed. However, this in vivo ultrasonographic technique was reliable in measuring the tendon stiffness properties across time in the controls and thus may be used to monitor the healing effect in a longer time frame. Our results also showed that some commonly-used clinical recovery measurements were poorly correlated with the tendon stiffness and thus should be interpreted cautiously in evaluating tendon healing.
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  • In Copyright
  • Weinhold, Paul S.
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  • University of North Carolina at Chapel Hill
  • Open access

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