title: Achilles tendon: functional anatomy and novel emerging models of imaging classification.
abstract: OBJECTIVE
  Ideally, a classification should have some prognostic value, and should therefore include precise information upon extent and location of the Achilles tendon disorders. We propose a new imaging and anatomical system to classify Achilles tendon disorders at imaging using US and MRI.
  
  
  METHODS
  We consider the non-insertional region as the tendon mid-portion, and distinguish the insertional component into a pre-insertion site, located about two centimetres above the calcaneum, and a calcaneal insertion, where the tendon is attached to the bone. On sagittal scans, we introduced a new classification which considers two main portions: "musculotendinous" and "insertional". In the context of the muscolotendinous portion, it is possible to find muscle fibres proximally, and the free tendon distally. This latter is made up of proximal, middle and distal portions. We also propose a 5 grade Doppler classification system to quantify blood flow, in which Grades I and II are respectively characterised by the presence of one and two vessels within the tendon; in Grades III, IV and V, the neovascularisation respectively involves less than 50 %, from 50 to 90 %, and more than 90 % of the tendon tissue. These proposed systems will require validation and possible modification to be applied to different tendons.
authors.affiliation: Department of Orthopaedic and Trauma Surgery, Campus Biomedico University of Rome, Via Alvaro del Portillo, Rome, Italy.
authors.forename: Angelo
authors.initials: A
authors.lastname: Del Buono
authors.forename: Otto
authors.initials: O
authors.lastname: Chan
authors.forename: Nicola
authors.initials: N
authors.lastname: Maffulli
mesh_terms: D000125:Achilles Tendon / Q000033:anatomy & histology* / Q000293:injuries / Q000502:physiology*; D000328:Adult; D002111:Calcaneus / Q000000981:diagnostic imaging / Q000473:pathology; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D008953:Models, Anatomic; D009389:Neovascularization, Pathologic; D013708:Tendon Injuries / Q000145:classification* / Q000000981:diagnostic imaging / Q000473:pathology; D014463:Ultrasonography