title: Tendon vascularity in overhead athletes with subacromial pain syndrome and its correlation with the resting subacromial space.
abstract: BACKGROUND
  Supraspinatus tendinopathy is one of the common causes of subacromial pain syndrome (SAPS) in overhead athletes. Changes in tendon vascularity have been reported in painful tendons; however, the prevalence and distribution have not been investigated in young overhead athletes.
  
  
  METHODS
  We conducted a cross-sectional study of 47 overhead athletes (male, 31; female, 16) aged 18 to 36 years with SAPS for >3 months. A sonographer graded the severity of the tendinopathy and area of vascularization. Ultrasound imaging was used to measure supraspinatus tendon thickness, vascularity, and resting subacromial space. A self-written program was used to semiquantify the intensity of vascularity, expressed as the vascular index.
  
  
  RESULTS
  The majority (87.2%) of the participants had signs of tendinopathy in the supraspinatus tendon, and 40 (85.1%) of the tendinopathic tendons had vascularity. The majority (66.0%) of the vascularized subjects presented with minimal increase in vascularity, and 19.1% had moderate to severe vascularization. Most (79.2%) of the vascularization was observed in the pericortical region. The vascular index was negatively correlated with the resting subacromial space in male athletes with a reduced subacromial space (ρ = -0.63; P = .038).
  
  
  CONCLUSIONS
  Of overhead athletes with SAPS, 87.2% had supraspinatus tendinopathy with minimal to moderate vascularization, with the majority of vascularization occurring in the pericortical region. In male athletes with a reduced subacromial space, greater vascularity in the supraspinatus tendon was associated with a smaller resting subacromial space.
authors.affiliation: Department of Rehabilitation Sciences, The Hong Kong Polytechnic University, Hung Hom, Hong Kong (SAR), China.
authors.forename: Sammi Sin Mei
authors.initials: SS
authors.lastname: Tsui
authors.affiliation: Department of Rehabilitation Sciences, The Hong Kong Polytechnic University, Hung Hom, Hong Kong (SAR), China.
authors.forename: Hio Teng
authors.initials: HT
authors.lastname: Leong
authors.affiliation: Department of Radiology and Imaging, Prince of Wales Hospital, Shatin, Hong Kong (SAR), China.
authors.forename: Vivian Yee Fong
authors.initials: VY
authors.lastname: Leung
authors.affiliation: Department of Health Technology and Informatics, The Hong Kong Polytechnic University, Hung Hom, Hong Kong (SAR), China.
authors.forename: Michael
authors.initials: M
authors.lastname: Ying
authors.affiliation: Department of Rehabilitation Sciences, The Hong Kong Polytechnic University, Hung Hom, Hong Kong (SAR), China. Electronic address: amy.fu@polyu.edu.hk.
authors.forename: Siu Ngor
authors.initials: SN
authors.lastname: Fu
mesh_terms: D000293:Adolescent; D000328:Adult; D056352:Athletes; D001265:Athletic Injuries / Q000000981:diagnostic imaging*; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008297:Male; D017006:Rotator Cuff / Q000098:blood supply* / Q000000981:diagnostic imaging; D020069:Shoulder Pain / Q000000981:diagnostic imaging*; D052256:Tendinopathy / Q000000981:diagnostic imaging*; D014463:Ultrasonography; D055815:Young Adult
keywords: Vascularity; overhead athletes; pathology of supraspinatus tendon; subacromial pain syndrome; subacromial space; supraspinatus tendon thickness