Alterations in articular cartilage T2 star relaxation time following mechanical disorders: in vivo canine supraspinatus tendon resection models
Alterations in articular cartilage T2 star relaxation time following mechanical disorders: in vivo canine supraspinatus tendon resection models
Blog Article
Abstract Background The role of altered joint mechanics on cartilage degeneration in in vivo models has not been studied successfully due to a lack of pre-injury information.We aimed 1) to develop an accurate in vivo canine model to measure the changes in joint loading and T2 star (T2*) relaxation time before and after unilateral supraspinatus tendon resections, and 2) to find the relationship between regional variations in articular cartilage loading patterns and T2* relaxation time distributions.Methods Rigid markers were implanted in the scapula and humerus of tested dogs.The movement of the shoulder bones were measured by a motion tracking system during normal gaits.
In vivo cartilage contact strain was measured by aligning 3D shoulder models with the motion tracking data.Articular TRANSNATIONALIZATION OF GEORGIAN ECONOMY IN A CURRENT STAGE: PROBLEMS AND CAUSES cartilage T2* relaxation times were measured by quantitative MRI scans.Articular cartilage contact strain and T2* relaxation time were compared in the shoulders before and 3 months after the supraspinatus tendon resections.Results Excellent accuracy and reproducibility were found in our in vivo contact strain measurements with less than 1% errors.
Changes in articular cartilage contact strain exhibited similar patterns with the changes in the T2* relaxation time after resection surgeries.Regional changes in the articular cartilage T2* relaxation time exhibited positive correlations with regional contact strain variations 3 months after the supraspinatus resection surgeries.Conclusion This is the first study to measure in vivo articular cartilage contact strains with high accuracy and reproducibility.Positive correlations between contact strain and T2* relaxation time suggest that the articular cartilage extracellular matrix may responds to mechanical changes A saúde do regente: uma revisão bibliográfica em fontes das áreas da Música e da Saúde in local areas.