title: What does normal tendon structure look like? New insights into tissue characterization in the Achilles tendon.
abstract: Recently, ultrasound tissue characterization (UTC) was introduced as a reliable method for quantification of tendon structure. Despite increasing publications on the use of UTC, it is striking that there is a lack of normative data in active adolescents. Therefore, the aim of this study was to provide normative values of the Achilles tendon as quantified by UTC. Seventy physiotherapy students (26 male and 44 female students) with no history of Achilles tendon injuries were recruited. The Achilles tendons were scanned with UTC to characterize tendon structure. This study demonstrated that Achilles tendons of active, healthy adolescents contained 54.6% echo type I, 42.8% echo type II, 2.2% echo type III, and 0.3% echo type IV at midportion. The comparison between insertion and midportion of the tendon showed more echo type II at insertion (P < 0.001). Furthermore, female tendons contained significantly more echo type II, in both insertion and midportion compared with male tendons (P = 0.004 and P = 0.003, respectively). The results of this study, with respect to the MDC (minimum detectable change), highlight differences in the UTC echopattern in the normal population (sex and regional location), which are important considerations for future studies.
authors.affiliation: Department of Rehabilitation Sciences and Physiotherapy, Ghent University, Ghent, Belgium.
authors.forename: E
authors.identifier: http://orcid.org/0000-0001-9303-6915
authors.initials: E
authors.lastname: Wezenbeek
authors.affiliation: Department of Rehabilitation Sciences and Physiotherapy, Ghent University, Ghent, Belgium.
authors.forename: N
authors.initials: N
authors.lastname: Mahieu
authors.affiliation: Department of Rehabilitation Sciences and Physiotherapy, Ghent University, Ghent, Belgium.|Department of Physical Therapy and Orthopedics, Ghent University, Ghent, Belgium.
authors.forename: T M
authors.initials: TM
authors.lastname: Willems
authors.affiliation: Department of Rehabilitation Sciences and Physiotherapy, Ghent University, Ghent, Belgium.|Department of Physical Medicine & Rehabilitation, Military Hospital of Base Queen Astrid, Belgian Defence, Brussels, Belgium.
authors.forename: D
authors.initials: D
authors.lastname: Van Tiggelen
authors.affiliation: Department of Physical Medicine and Rehabilitation, Ghent University Hospital, Ghent, Belgium.
authors.forename: M
authors.initials: M
authors.lastname: De Muynck
authors.affiliation: Department of Movement and Sport Sciences, Ghent University, Ghent, Belgium.
authors.forename: D
authors.initials: D
authors.lastname: De Clercq
authors.affiliation: Department of Rehabilitation Sciences and Physiotherapy, Ghent University, Ghent, Belgium.|Department of Physiotherapy, Aspetar, Doha, Qatar.
authors.forename: E
authors.initials: E
authors.lastname: Witvrouw
mesh_terms: D000125:Achilles Tendon / Q000033:anatomy & histology* / Q000000981:diagnostic imaging*; D000293:Adolescent; D005260:Female; D006801:Humans; D008297:Male; D012016:Reference Values; D014463:Ultrasonography
keywords: Achilles tendon; adolescents; echo type distribution; ultrasound; ultrasound tissue characterization