title: Effect of Bankart repair on the loss of range of motion and the instability of the shoulder joint for recurrent anterior shoulder dislocation.
abstract: BACKGROUND
  Bankart repair postoperative complications include loss of shoulder motion and shoulder instability. The primary reason that postoperative complications develop may be excessive imbrication of the anterior band of the inferior glenohumeral ligament (AIGHL) or inadequate repair position. The purpose of this study was to quantitatively evaluate the influence of inadequate repair by computer simulation for a normal shoulder joint.
  
  
  METHODS
  Magnetic resonance images of 10 normal shoulder joints were acquired for 7 positions every 30° from the maximum internal rotation to the maximum external rotation with the arm abducted at 90°. The shortest 3-dimensional path of the AIGHL in each rotational orientation was calculated. We used computer simulations to anticipate the loss of motion and instability by changing the AIGHL length and insertion sites on the glenoid.
  
  
  RESULTS
  The AIGHL length measured 50 ± 5 mm at the maximum external shoulder rotation. AIGHL shortening by 3, 6, and 9 mm made the angle of maximum external rotation 80°, 68°, and 54°, respectively. A superior deviation of 3, 6, and 9 mm on the glenoid insertion resulted in a maximum external rotation angle of 85°, 79°, and 77°. An inferior deviation of 3, 6, and 9 mm produced humeral head translation of 1.7, 2.9, and 3.6 mm.
  
  
  CONCLUSIONS
  Simulation of both excessive imbrication and deviation of the insertion position led to quantitative prediction of the resulting loss of motion and instability. These findings will be useful for anticipating complications after Bankart repair.
  
  
  METHODS
  Basic science study, computer modeling, imaging.
authors.affiliation: Department of Orthopaedic Biomaterial Science, Osaka University Graduate School of Medicine, Osaka, Japan.
authors.forename: Koji
authors.initials: K
authors.lastname: Shibano
authors.affiliation: Koishi Orthopaedic Clinic, Kyoto, Japan.
authors.forename: Hayato
authors.initials: H
authors.lastname: Koishi
authors.affiliation: Department of Orthopaedic Surgery, Osaka University Graduate School of Medicine, Osaka, Japan.
authors.forename: Kazuma
authors.initials: K
authors.lastname: Futai
authors.affiliation: Department of Orthopaedic Surgery, Osaka University Graduate School of Medicine, Osaka, Japan.
authors.forename: Hideki
authors.initials: H
authors.lastname: Yoshikawa
authors.affiliation: Department of Orthopaedic Biomaterial Science, Osaka University Graduate School of Medicine, Osaka, Japan. Electronic address: sugamoto@ort.med.osaka-u.ac.jp.
authors.forename: Kazuomi
authors.initials: K
authors.lastname: Sugamoto
mesh_terms: D000328:Adult; D002062:Bursitis / Q000209:etiology / Q000503:physiopathology; D003198:Computer Simulation; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional; D007593:Joint Instability / Q000209:etiology / Q000503:physiopathology; D008023:Ligaments, Articular / Q000502:physiology*; D008279:Magnetic Resonance Imaging; D008297:Male; D019637:Orthopedic Procedures / Q000009:adverse effects; D016059:Range of Motion, Articular; D012008:Recurrence; D012782:Shoulder / Q000502:physiology; D012783:Shoulder Dislocation / Q000209:etiology / Q000503:physiopathology; D012785:Shoulder Joint / Q000502:physiology*; D034941:Upper Extremity / Q000502:physiology; D055815:Young Adult
keywords: 3-dimensional kinematics; Bankart repair; Shoulder; anterior band of the inferior glenohumeral ligament; in vivo; simulation