Glenoid exposure in shoulder arthroplasty: the role of soft tissue releases.

BACKGROUND

The deltopectoral approach is commonly used in shoulder arthroplasty. Various soft tissue releases can be performed to obtain adequate glenoid exposure, but their effectiveness is not known. The purpose of this study was to (1) quantify the effects of various releases on the amount of glenoid surface area exposure and (2) determine if common soft tissue releases performed about the shoulder significantly improve exposure of the glenoid.

METHODS

A standard deltopectoral approach was used on cadaveric shoulders (n=8) in the beach chair position. The releases performed were as follows: long head of biceps, pectoralis major tendon, inferior capsule, and posterior capsule. Following each release, a custom-designed jig was used to mark the exposed glenoid surface. The glenoid was then digitized using a 3D surface scanner to quantify the exposed surface area with each release.

RESULTS

The mean glenoid surface area exposure prior to any releases was 57% (SD 8%). Following release of the long head of biceps, exposure increased to 69% (SD 10%). The exposed area was increased to 83% (SD 6%) with release of the pectoralis major, and 93% (SD 2%) with inferior capsule. The entire glenoid was exposed following posterior capsule release.

CONCLUSIONS

Release of the long head of biceps, pectoralis major, and inferior and posterior capsule all independently led to significant increases in glenoid surface exposure in the deltopectoral approach. Mean surface area exposed with all 3 releases was 93%. Although posterior capsular release improved exposure, the results of this study suggest that this is rarely necessary.