There was a transient change in UTC echopattern in the Achilles tendon as a result of an Australian football game in individuals without a history of lower limb tendinopathy.

No abstract

Pre-season injuries are common and may be due to a reintroduction of training loads. Tendons are sensitive to changes in load, making them vulnerable to injury in the pre-season. This study investigated changes in Achilles tendon structure on ultrasound tissue characterization (UTC) over the course of a 5-month pre-season in elite male Australian football players. Eighteen elite male Australian football players with no history of Achilles tendinopathy and normal Achilles tendons were recruited. The left Achilles tendon was scanned with UTC to quantify the stability of the echopattern. Participants were scanned at the start and completion of a 5-month pre-season. Fifteen players remained asymptomatic over the course of the pre-season. All four echo-types were significantly different at the end of the pre-season, with the overall echopattern suggesting an improvement in Achilles tendon structure. Three of the 18 participants developed Achilles tendon pain that coincided with a change in the UTC echopattern. This study demonstrates that the UTC echopattern of the Achilles tendon improves over a 5-month pre-season training period, representing increased fibrillar alignment. However, further investigation is needed to elucidate with this alteration in the UTC echopattern results in improved tendon resilience and load capacity.

Ultrasonography (US) is used to visualise tendon structure. However, its capacity to detect early disintegration, to reproducibly monitor progress of pathology or repair, and to objectively evaluate effect of therapies and exercise is poor. Furthermore, US is not able to reliably assess tissue integrity as its limits of resolution means that every US image is a mixture of reflections (of relatively large structures like secondary tendon bundles, fasciculi) and interfering echoes (generated by smaller entities like fibrils and cells) that cannot be discriminated by the eye.Therefore, a method for computerised ‘ultrasound tissue characterisation’ (UTC) was created. A high-resolution probe is fixed in a tracking device and moves automatically along a tendon's long axis, collecting transverse images at even distances of 0.2 mm. By compounding contiguous transverse images, a 3-D ultrasound data-block is created that can be used for (A) tomographic visualisation in 3 planes of view plus a 3-D rendered view, and for (B) tissue characterisation and quantification of 3-D architecture of the tendon matrix.Dedicated UTC-Algorithms can discriminate four different echo-types, namely: echo-type I, generated by reflections at intact and aligned tendon bundles, echo-type II, generated by reflections at discontinuous or wavy tendon bundles, echo-type III, generated by interfering echoes from mainly fibrillar components, and echo-type IV, generated by mainly cellular components and fluid in amorphous tissue. Initially, UTC was validated by precisely matching UTC-processed images with corresponding tendon specimens, sampled from isolated flexor tendons in the horse. These four echo-types appeared to be highly correlated with histo-morphological characteristics, showing the discriminative power of UTC for tissue characterisation.Since 2005, UTC is implemented for human Achilles and patellar tendons and has been used in multiple research projects too. Some relevant observations in these studies are:Inter-and intra-observer reproducibility of both data-collection and analysis appeared to be high (ICC over 0.90), indicating an excellent reliability for longitudinal monitoring.Observational studies of UTC parameters related to age revealed that Achilles tendons of young persons (24–30 years of age) are characterised by 80–85% echo-type I, 10–15% echo-type II and only 2–5% type III plus IV echoes. Initial deterioration, mostly asymptomatic, was characterised by increasing percentages of echo-types II (remodelling or fibrosis) and/or III plus IV (fibrillar and cellular disintegration), mainly localised in the postero-medial quadrant of the Achilles tendon. In patients with diabetes type II and in persons with lateral foot-landing pattern, the Achilles tendons demonstrated significantly more changes on UTC compared to matched controls.Patients suffering tendinopathy (avg. age 45 years) have significantly higher percentages of echo-types II, III and/or IV, compared with a matching group of asymptomatic control persons.1Significant increases ...