Assessing glenosphere position: superior approach versus deltopectoral for reverse shoulder arthroplasty

The anterosuperior (AS) approach for reverse total shoulder arthroplasty (RTSA) has been reported as a risk factor for baseplate malposition because of potential difficulty in glenoid exposure. The objective of this study was to compare glenoid baseplate position between the AS and deltopectoral (DP) approaches in relation to the surgeon's experience and to evaluate the effect of placement on clinical outcomes.

There were 109 shoulders that underwent RTSA for cuff tear arthropathy or osteoarthritis with cuff tearing by a single surgeon. The AS approach was used in 87 shoulders. Clinical, radiographic, and functional outcomes were assessed for all patients with a minimum of 2 years of follow-up. Initial postoperative radiographs of all 109 shoulders were assessed for baseplate positioning.

The mean change in glenoid inclination was 3.0° inferior with the AS approach and 2.5° inferior with the DP approach (P = .68). Pain scores (P = .14), range of motion, and American Shoulder and Elbow Surgeons scores (P = .16) improved in both groups, without a difference between approach. Scapular notching was noted in 68.5% of AS shoulders and 72.4% of DP shoulders (P = .78). Over time, there was a trend to place the glenoid baseplate more caudal with less inferior tilt.

Both approaches produce similar baseplate position, clinical outcomes, and rates of scapular notching when they are used for RTSA. Attempts to inferiorize the glenoid baseplate through the AS approach may increase the risk of superior inclination.