Glenohumeral joint volume reduction with progressive release and shifting of the inferior shoulder capsule.

The inferior capsular shift procedure described by Neer is an effective treatment for multidirectional shoulder instability. To determine the amount of volume reduction that occurs with the inferior capsular shift procedure, 13 cadaver shoulders were dissected down to the capsule. A viscous liquid was injected into each shoulder and the baseline volume recorded. A humeral-based capsular release to the 8 o'clock position (right shoulder) was performed, the capsule was shifted, and the volume was recorded. The capsule was released further to the 6 o'clock position and then to the 4 o'clock position. The mean shoulder volume significantly dropped after each successive shift. From baseline, the volume decreased 33% after the first shift, 42% after the second, and 66% after the third. Progressive release of the capsule results in significantly more volume reduction owing to greater elimination of the inferior axillary pouch. A more complete glenohumeral capsular release may be necessary in certain clinical situations.