Methods of Assessing Human Tendon Metabolism and Tissue Properties in Response to Changes in Mechanical Loading

In recent years a number of methodological developments have improved the opportunities to study human tendon. Microdialysis enables sampling of interstitial fluid in the peritendon tissue, while sampling of human tendon biopsies allows direct analysis of tendon tissue for gene- and protein expression as well as protein synthesis rate. Further the (14)C bomb-pulse method has provided data on long-term tissue turnover in human tendon. Non-invasive techniques allow measurement of tendon metabolism (positron emission tomography (PET)), tendon morphology (magnetic resonance imaging (MRI)), and tendon mechanical properties (ultrasonography combined with force measurement during movement). Finally, 3D cell cultures of human tendon cells provide the opportunity to investigate cell-matrix interactions in response to various interventions.