title: Glenohumeral joint motion after subscapularis tendon repair: an analysis of cadaver shoulder models.
abstract: BACKGROUND
  As for the surgical treatment of the rotator cuff tears, the subscapularis tendon tears have recently received much attention for the mini-open or arthroscopic repair. The results of surgical repair for the subscapularis tendon tear are satisfactory, but the range of external rotation is reported to be restricted after the repair. The purpose of this study was to evaluate the range of glenohumeral joint motion after repairs of various sizes of subscapularis tendon tears.
  
  
  METHODS
  Using eight fresh frozen human cadaveric shoulders (mean age at death, 81.5 years), three sizes of subscapularis tendon tear (small, medium, and large) were made and then repaired. With the scapula fixed to the wooden jig, the end-range of glenohumeral motion was measured with passive movement applied through 1.0-Nm torque in the directions of scapular elevation, flexion, abduction, extension, horizontal abduction, and horizontal adduction. The passive end-ranges of external and internal rotation in various positions with rotational torque of 1.0 Nm were also measured. Differences in the ranges among the three type tears were analyzed.
  
  
  RESULTS
  As tear size increased, range of glenohumeral motion in horizontal abduction after repair decreased gradually and was significantly decreased with the large size tear (P < 0.01). The end-range of external rotation decreased progressively with increasing tear size in every glenohumeral position. The prominent decrease in external rotation (around 40° reduction from intact shoulders) was observed in shoulders after repair of large size tear at 30° to 60° of scapular elevation and abduction.
  
  
  CONCLUSIONS
  As the size of the subscapularis tendon tear increased, the passive ranges of horizontal abduction and external rotation of the glenohumeral joint after repair decreased significantly. In shoulders with a subscapularis tendon tear, it is necessary to consider the reduction of external rotation depending on tear size.
authors.affiliation: Department of Orthopaedic Surgery, Shizuoka General Hospital, 4-27-1 Kitaandou, Aoi-ku, Shizuoka-city, Shizuoka 420-8527, Japan. teiichi-sano@i.shizuoka-pho.jp.
authors.forename: Teiichi
authors.initials: T
authors.lastname: Sano
authors.forename: Mitsuhiro
authors.initials: M
authors.lastname: Aoki
authors.forename: Yoshitaka
authors.initials: Y
authors.lastname: Tanaka
authors.forename: Tomoki
authors.initials: T
authors.lastname: Izumi
authors.forename: Mineko
authors.initials: M
authors.lastname: Fujimiya
authors.forename: Toshihiko
authors.initials: T
authors.lastname: Yamashita
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002102:Cadaver; D005260:Female; D061165:Glenoid Cavity / Q000473:pathology / Q000502:physiology / Q000601:surgery*; D006801:Humans; D008297:Male; D016059:Range of Motion, Articular / Q000502:physiology; D012782:Shoulder / Q000473:pathology / Q000502:physiology / Q000601:surgery; D012785:Shoulder Joint / Q000473:pathology / Q000502:physiology / Q000601:surgery*; D013708:Tendon Injuries / Q000503:physiopathology / Q000601:surgery*