Evaluation for the evolution of achilles tendinopathy and the feature of tendon biomechanics using quantitative analysis of tissue diffusion by ultrasound elastography

Abstract

Objective To explore the application value of quantitative analysis of tissue diffusion by ultrasound elastography in evaluating the evolution of achilles tendinopathy and indirectly reflecting the feature of tendon biomechanics. Methods Rabbits underwent 0.1 ml (group M) or 0.3 ml (group S) collagenase or 0.2 ml saline (group C) injection. The percentage of area displaying blue (%AREA) in the area of interest was measured by the diffusion quantitative technique of ultrasound elastography at baseline and 1, 3, 7 and 14 days after model. The achilles tendon was obtained for pathological examination to observe the changes of collagen fibers and tested to measure the maximum tensile load by the universal testing machine. Results (1) The %AREAs in group M and S at 1, 3, 7 and 14 days after model were smaller than those in group C (P 0.05). The maximum tensile load in group S was significant lower than those in group M and C after model (P<0.05), and arrived its lowest point at 3 days after model. (3) The %AREA was positively associated with the maximum tensile load of achilles tendon (r=0.87, P<0.001). Conclusions Ultrasound elastography can dynamically monitor the evolution of achilles tendinopathy and reflect the biomechanical state of achilles tendon. Key words: Elasticity imaging techniques; Rabbit; Achilles tendin; Biomechanics