title: Quantitative ultrasound facilitates the exploration of morphological association of the long head biceps tendon with supraspinatus tendon full thickness tear.
abstract: BACKGROUND
  Pathology of the long head biceps tendon (LHBT) is associated with rotator cuff tears but whether the LHBT texture changes following supraspinatus tendon full thickness tear (SSFT) can be detected at the extra-articular segment remains unknown. This cross-sectional study aimed to explore the morphological differences of the LHBT in shoulders with and without deficient rotator cuffs by using quantitative ultrasound.
  
  
  METHODS
  We selected 145 cases with SSFT and 145 age-and- gender-matched controls. The width, thickness, flattening ratio, cross-sectional area, and echogenicity ratio of the LHBT were measured and a general linear model was used to clarify the relationship between rotator cuff pathology and LHBT morphology. The receiver operating characteristic curves of each parameter were constructed for SSFT discrimination and the maximal Youden indexes were used to define the best cut-off points.
  
  
  RESULTS
  We found increased thickness and cross-sectional area but decreased flattening ratio in shoulders with SSFT, and no between-group differences in the width and echogenicity ratio. The LHBT appearance was modified by biceps peritendinous effusion and medial subluxation, but not by the size of SSFT. The flattening ratio was the best discriminator for SSFT with an area under curve of 0.81 (95% confidence interval, 0.76-0.86). The cut-off values to differentiate between the non-tear and tear groups were 2.00 mm of the thickness, 1.73 of the flattening ratio and 10.53 mm(2) of the cross-sectional area.
  
  
  CONCLUSIONS
  Quantitative ultrasound facilitated the detection of the LHBT morphological changes following SSFT and demonstrated its potential utility in discriminating rotator cuff deficiency.
authors.affiliation: Department of Physical Medicine and Rehabilitation, National Taiwan University Hospital, BeiHu Branch and National Taiwan University College of Medicine, Taipei, Taiwan; Graduate Institute of Epidemiology and Preventive Medicine, National Taiwan University, Taipei, Taiwan.
authors.forename: Ke-Vin
authors.initials: KV
authors.lastname: Chang
authors.affiliation: Department of Physical Medicine and Rehabilitation, National Taiwan University Hospital and National Taiwan University College of Medicine, Taipei, Taiwan.
authors.forename: Wen-Shiang
authors.initials: WS
authors.lastname: Chen
authors.affiliation: Department of Physical Medicine and Rehabilitation, National Taiwan University Hospital and National Taiwan University College of Medicine, Taipei, Taiwan.
authors.forename: Tyng-Guey
authors.initials: TG
authors.lastname: Wang
authors.affiliation: Department of Physical Medicine and Rehabilitation, National Taiwan University Hospital Chu-Tung Branch, Hsinchu, Taiwan.
authors.forename: Chen-Yu
authors.initials: CY
authors.lastname: Hung
authors.affiliation: Graduate Institute of Epidemiology and Preventive Medicine, National Taiwan University, Taipei, Taiwan; Department of Internal Medicine, National Taiwan University Hospital and National Taiwan University College of Medicine, Taipei, Taiwan.
authors.forename: Kuo-Liong
authors.initials: KL
authors.lastname: Chien
mesh_terms: D000368:Aged; D019540:Area Under Curve; D003430:Cross-Sectional Studies; D003710:Demography; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012372:ROC Curve; D012189:Retrospective Studies; D017006:Rotator Cuff / Q000473:pathology; D000070636:Rotator Cuff Injuries; D012785:Shoulder Joint / Q000000981:diagnostic imaging*; D013710:Tendons / Q000000981:diagnostic imaging / Q000473:pathology*; D014463:Ultrasonography