title: Pathological tendons maintain sufficient aligned fibrillar structure on ultrasound tissue characterization (UTC).
abstract: Structural disorganization in the tendon is associated with tendinopathy, with little research investigating whether disorganization overwhelms the overall structural integrity of the tendon. This study investigated the mean cross-sectional area (CSA) of aligned fibrillar structure as detected by ultrasound tissue characterization (UTC) in the pathological and normal Achilles and patellar tendons. Ninety-one participants had their Achilles and/or patellar tendons scanned using UTC to capture a three-dimensional image of the tendon and allow a semi-quantification of the echopattern. The mean CSA of aligned fibrillar structure (echo type I + II) and disorganized structure (echo type III + IV) was calculated based on UTC algorithms. Each tendon was classified as either pathological or normal based solely on gray-scale ultrasound. The mean CSA of aligned fibrillar structure was significantly greater (P ≤ 0.001) in the pathological tendon compared with the normal tendon, despite the pathological tendon containing greater amounts of disorganized structure (P ≤ 0.001). A significant relationship was observed between the mean CSA of disorganized structure and anteroposterior diameter of the Achilles (R(2)  = 0.587) and patellar (R(2)  = 0.559) tendons. This study is the first to show that pathological tendons have sufficient levels of aligned fibrillar structure. Pathological tendons may compensate for areas of disorganization by increasing in tendon thickness.
authors.affiliation: Monash Tendon Research Group (MONSTERs), Monash University, Frankston, Victoria, Australia.|Australian Centre of Research into Injury in Sport and its Prevention (ACRISP), Federation University, Ballarat, Victoria, Australia.
authors.forename: S I
authors.initials: SI
authors.lastname: Docking
authors.affiliation: Monash Tendon Research Group (MONSTERs), Monash University, Frankston, Victoria, Australia.|Australian Centre of Research into Injury in Sport and its Prevention (ACRISP), Federation University, Ballarat, Victoria, Australia.
authors.forename: J
authors.initials: J
authors.lastname: Cook
mesh_terms: D000125:Achilles Tendon / Q000000981:diagnostic imaging*; D000293:Adolescent; D000328:Adult; D000465:Algorithms; D002648:Child; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional; D008297:Male; D008875:Middle Aged; D009929:Organ Size; D017847:Patellar Ligament / Q000000981:diagnostic imaging*; D012189:Retrospective Studies; D052256:Tendinopathy / Q000000981:diagnostic imaging* / Q000473:pathology*; D014463:Ultrasonography / Q000379:methods; D055815:Young Adult
keywords: Achilles tendon; patellar tendon; tendon pathology; ultrasound tissue characterization