title: Sequential volume reduction with capsular plications: relationship between cumulative size of plications and volumetric reduction for multidirectional instability of the shoulder.
abstract: OBJECTIVE
  To quantify the relationship between the amount of shoulder capsule imbricated with a simple stitch and the degree of glenohumeral volume reduction in a multidirectional instability model. Secondary purposes were to identify the number of arthroscopic plication stitches required to reduce the shoulder volume equal to that of an open lateral-based inferior capsular shift and to compare volume reductions between suture anchor and suture-only capsular plication stitches.
  
  
  METHODS
  Controlled laboratory study.
  
  
  METHODS
  Twelve fresh-frozen cadaveric shoulders (mean age, 64.4 years) were dissected to the level of the rotator cuff. A viscous liquid was injected into each joint, and measurements were taken before and after six 1-cm arthroscopic capsular plication stitches were performed. The sizes of the capsular plications were measured to quantify the amount of capsule imbricated with each simple stitch. A repeated random-intercept regression model was fitted for each outcome, with significance set at P = .05.
  
  
  RESULTS
  There was a near-linear relationship, with each 1 cm of total plication equaling 10% volume reduction up to 4.0 cm. After this, each additional 1-cm plication stitch resulted in 2% to 6% more reduction (mean, 4%). Five simple plication stitches reduced the volume by 52% in the suture anchor group and 49% in the suture-only group. The suture anchor achieved 3% greater volumetric reduction than the suture-only plication stitches, but this effect was not statistically significant (P = .06). Conclusion/
  
  
  CONCLUSIONS
  A 1-cm capsular plication stitch results in a roughly 10% volume reduction of the glenohumeral joint. Five simple capsular plication stitches result in a volume reduction equivalent to an open lateral-based capsular shift.
authors.affiliation: Division of Orthopaedics, The University of Alabama at Birmingham, 1313 13th Street South, Birmingham, AL 35205, USA. bponce@uab.edu
authors.forename: Brent A
authors.initials: BA
authors.lastname: Ponce
authors.forename: Seth D
authors.initials: SD
authors.lastname: Rosenzweig
authors.forename: Kevin J
authors.initials: KJ
authors.lastname: Thompson
authors.forename: John
authors.initials: J
authors.lastname: Tokish
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001182:Arthroscopy; D002102:Cadaver; D005260:Female; D006801:Humans; D017746:Joint Capsule / Q000601:surgery*; D007593:Joint Instability / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D012785:Shoulder Joint / Q000033:anatomy & histology / Q000601:surgery*; D053441:Suture Anchors; D013536:Suture Techniques