Volumetric change in the shoulder capsule after open inferior capsular shift versus arthroscopic thermal capsular shrinkage: a cadaveric model.

The purpose of this study was to compare the percentage of glenohumeral intracapsular volume reduction after open inferior capsular shift and arthroscopic thermal capsulorrhaphy. Twelve matched, fresh-frozen cadaveric shoulders were used for the study. Intraarticular glenohumeral volume measurements were obtained by injecting a viscous fatty acid sulfate solution into the joint. In the 6 right shoulders, a standard anterior-inferior capsular shift was performed, and in the 6 matching left shoulders, an arthroscopic thermal capsular shrinkage was performed. After the procedures, the capsular volumes were re-measured. The open inferior shift procedure resulted in a mean decrease in glenohumeral volume of 50.2% (range, 43%-56%). Arthroscopic thermal capsulorrhaphy decreased shoulder intraarticular volume by a mean of 29.7% (range, 26%-36%). Both the open capsular shift and arthroscopic thermal shrinkage procedures produced well-documented volumetric reductions in the shoulder capsules. The open shift reduced intraarticular shoulder volume significantly more than arthroscopic thermal capsular shrinkage.