title: Effect of glenohumeral position on contact pressure between the capsulolabral complex and the glenoid in free ALPSA and Bankart lesions.
abstract: OBJECTIVE
  Anterior shoulder dislocation is a common injury, but the optimal management of dislocation remains controversial. We hypothesized that reducing the shoulder in externally rotated position would aid the reduction in capsulolabral lesions. Thus, in this study, contact pressure between the capsulolabral lesion and the glenoid in free ALPSA and Bankart lesions was measured using a cadaver model.
  
  
  METHODS
  In 10 specimens, the humerus was externally rotated by abduction on the coronal plane to measure the contact pressure between the capsulolabral complex and glenoid in free ALPSA and Bankart lesions using a Tekscan pressure system. Stability of the joint was confirmed using the Vicon motion analysis system.
  
  
  RESULTS
  In the normal shoulder joint, the peak pressure between the subscapularis muscle and the anterior capsule according to the location of the glenohumeral joint decreased to 83.4 ± 21.2 kPa in the 0° abduction and -30° external rotation positions and showed a 300.7 ± 42.9 kPa peak value in the 60° abduction and 60° external rotation positions. In both free ALPSA and Bankart lesions, the lowest pressure between the labral lesion and the glenoid was measured at 0° abduction and -30° external rotation, and the highest pressure was recorded at 60° external rotation and 60° abduction.
  
  
  CONCLUSIONS
  The contact pressure between the capsulolabral complex and the glenoid significantly increased when the abduction and external rotation angles were increased. Based on our results, the conservative management in free ALPSA lesions would respond better than Bankart lesions.
  YWMR-12-0-038.
authors.affiliation: Department of Orthopedic Surgery, Wonju Christian Severance Hospital, Wonju College of Medicine, Yonsei University, Ilsan-ro 20, Wonju-si, Gangwon-do, 220-701, Republic of Korea.
authors.forename: DooSup
authors.initials: D
authors.lastname: Kim
authors.affiliation: Department of Orthopedic Surgery, Wonju Christian Severance Hospital, Wonju College of Medicine, Yonsei University, Ilsan-ro 20, Wonju-si, Gangwon-do, 220-701, Republic of Korea. hjchung29@yonsei.ac.kr.
authors.forename: HoeJeong
authors.identifier: http://orcid.org/0000-0003-3337-1177
authors.initials: H
authors.lastname: Chung
authors.affiliation: Department of Orthopaedic Surgery, DaeGu Armed Forced Hospital, Daegu, Republic of Korea.
authors.forename: Chang-Ho
authors.initials: CH
authors.lastname: Yi
authors.affiliation: Department of Orthopedic Surgery, Wonju Christian Severance Hospital, Wonju College of Medicine, Yonsei University, Ilsan-ro 20, Wonju-si, Gangwon-do, 220-701, Republic of Korea.
authors.forename: Yeo-Seung
authors.initials: YS
authors.lastname: Yoon
authors.affiliation: Sensory Motor Performance Program, Rehabilitation Institute of Chicago, Chicago, IL, USA.|Department of Physical Medicine and Rehabilitation, Northwestern University, Chicago, IL, USA.
authors.forename: Jongsang
authors.initials: J
authors.lastname: Son
authors.affiliation: Department of Biomechanical Engineering, Yonsei University, Seoul, Republic of Korea.
authors.forename: Youngho
authors.initials: Y
authors.lastname: Kim
authors.affiliation: Department of Orthopedic Surgery, Wonju Christian Severance Hospital, Wonju College of Medicine, Yonsei University, Ilsan-ro 20, Wonju-si, Gangwon-do, 220-701, Republic of Korea.
authors.forename: Myoung-Gi
authors.initials: MG
authors.lastname: On
authors.affiliation: Department of Orthopaedic Surgery, Gangdong Yonsei Hospital, Seoul, Republic of Korea.
authors.forename: JaeHyung
authors.initials: J
authors.lastname: Yang
mesh_terms: D002102:Cadaver; D051445:Fibrocartilage / Q000503:physiopathology; D006801:Humans; D006811:Humerus / Q000293:injuries / Q000503:physiopathology; D007593:Joint Instability / Q000503:physiopathology* / Q000628:therapy*; D008297:Male; D008349:Manipulation, Orthopedic; D008875:Middle Aged; D011312:Pressure; D012399:Rotation; D017006:Rotator Cuff / Q000503:physiopathology; D000070636:Rotator Cuff Injuries; D012540:Scapula / Q000503:physiopathology*; D012783:Shoulder Dislocation / Q000503:physiopathology* / Q000628:therapy*; D000070599:Shoulder Injuries; D012785:Shoulder Joint / Q000503:physiopathology*
keywords: Bankart lesion; Biomechanical study; Cadaver study; Free ALPSA lesion; Shoulder dislocation