Arthroscopic multi-pleated capsular plication compared with open inferior capsular shift for reduction of shoulder volume in a cadaveric model.

PURPOSE: The purpose of this study was to compare a new arthroscopic technique for capsular plication with the standard open inferior capsular shift for reducing volume in a multidirectional instability model.

METHODS: Seven fresh-frozen cadaveric shoulders (mean age, 55 years) were dissected down to the capsule. A viscous liquid was injected into each shoulder joint and the volume measured. An arthroscopic multi-pleated anterior, posterior, and inferior capsular plication was performed through a single anterior and posterior portal by use of bioabsorbable suture anchors. The shoulder joint volume was again measured, and the sutures were then cut to restore the volume back to the original size. A humerus-based capsular release from 4 o'clock to 6 o'clock to the 8-o'clock position (right shoulder) was performed, the capsule shifted, and the volume recorded. A repeated-measures analysis of variance test was used with significance set at P = .05.

RESULTS: The mean baseline shoulder volume was 20 +/- 9 mL (range, 10 to 35 mL). The arthroscopic plication resulted in a mean decrease of 58% +/- 12%. The open inferior capsular shift resulted in a mean difference of 45% +/- 11%. There was a significant decrease in volume between the arthroscopic and open capsular shifts (P = .006, beta = .92).

CONCLUSIONS: This study proved our hypothesis that with this new arthroscopic technique for capsular plication, arthroscopic volume reduction can be achieved at least as well as with the standard open technique.

CLINICAL RELEVANCE: As the clinical results in the literature improve with improvements in arthroscopic techniques for treating shoulder instability, this arthroscopic method of repair could become invaluable in overcoming the challenge of capsular volume reduction when addressing multidirectional shoulder instability arthroscopically.