title: The effect of the arthroscopic augmentation of the subscapularis tendon on shoulder instability and range of motion: A biomechanical study.
abstract: Anterior shoulder dislocation is common. The treatment of recurrence with glenoid bone defect is still considered controversial. A new arthroscopic subscapularis augmentation has recently been described that functions to decrease the anterior translation of the humeral head. The purpose of the presented study was to examine the biomechanical effect on glenohumeral joint motion and stability.
  
  
  
  Eight fresh frozen cadaver shoulders were studied by use of a force guided industrial robot fitted with a six-component force-moment sensor to which the humerus was attached. The testing protocol includes measurement of glenohumeral translation in the anterior, anterior-inferior and inferior directions at 0°, 30° and 60° of glenohumeral abduction, respectively, with a passive humerus load of 30N in the testing direction. The maximum possible external rotation was measured at each abduction angle applying a moment of 1Nm. Each specimen was measured in a physiologic state, as well as after Bankart lesion with an anterior bone defect of 15-20% of the glenoid, after arthroscopic subscapularis augmentation and after Bankart repair.
  
  
  
  The arthroscopic subscapularis augmentation decreased the anterior and anterior-inferior translation. The Bankart repair did not restore the mechanical stability compared to the physiologic shoulder group. External rotation was decreased after arthroscopic subscapularis augmentation compared to the physiologic state, however, the limitation of external rotation was decreased at 60° abduction.
  
  
  
  The arthroscopic subscapularis augmentation investigated herein was observed to restore shoulder stability in an experimental model.
authors: Department of Traumatology and Reconstructive Surgery, Eberhard Karls University Tübingen, BG Trauma Center Tübingen, Germany. Electronic address: schroeter.steffen@t-online.de.
authors: S
authors: S
authors: Schröter
authors: Laboratory for Biomechanics and Biomaterials, Department of Orthopaedics, Medical University Hannover, Hannover, Germany.
authors: M
authors: M
authors: Krämer
authors: Laboratory for Biomechanics and Biomaterials, Department of Orthopaedics, Medical University Hannover, Hannover, Germany.
authors: B
authors: B
authors: Welke
authors: Laboratory for Biomechanics and Biomaterials, Department of Orthopaedics, Medical University Hannover, Hannover, Germany.
authors: C
authors: C
authors: Hurschler
authors: Pellegrini Hospital Orthopaedic and Traumatology Unit, Naples, Italy.
authors: R
authors: R
authors: Russo
authors: Department of Traumatology and Reconstructive Surgery, Eberhard Karls University Tübingen, BG Trauma Center Tübingen, Germany.
authors: M
authors: M
authors: Herbst
authors: Department of Traumatology and Reconstructive Surgery, Eberhard Karls University Tübingen, BG Trauma Center Tübingen, Germany.
authors: U
authors: U
authors: Stöckle
authors: Department of Traumatology and Reconstructive Surgery, Eberhard Karls University Tübingen, BG Trauma Center Tübingen, Germany.
authors: A
authors: A
authors: Ateschrang
authors: Sports Medicine Unit, San Giovanni-Addolorata Hospital, Rome, Italy.
authors: M
authors: M
authors: Maiotti
mesh_terms: D000328:Adult; D001696:Biomechanical Phenomena; D002062:Bursitis / Q000503:physiopathology; D002102:Cadaver; D005260:Female; D006801:Humans; D058430:Humeral Head; D007593:Joint Instability / Q000601:surgery; D008297:Male; D008875:Middle Aged; D016059:Range of Motion, Articular / Q000502:physiology*; D012008:Recurrence; D012399:Rotation; D017006:Rotator Cuff / Q000502:physiology* / Q000601:surgery*; D012540:Scapula / Q000601:surgery; D012782:Shoulder / Q000502:physiology* / Q000601:surgery*; D012783:Shoulder Dislocation / Q000601:surgery; D012785:Shoulder Joint / Q000502:physiology*; D014945:Wound Healing
keywords: A.S.A.; Arthroscopic subscapularis augmentation; Glenoid bone defect; Shoulder dislocation; Subscapularis elongation