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Updated: Feb 13, 2026
Reverse Total Shoulder Arthroplasty
Published on: July 5, 2011
Humeral and glenoid lateralization based on glenoid-humeral axis interval results in functional improvements
1Department of Orthopaedic Surgery, University Hospital, Shiga University of Medical Science, Otsu, Shiga, Japan.
Background:
The optimal glenoid or humeral lateralization in reverse total shoulder arthroplasty (rTSA) remains unknown. The author hypothesized that stepwise humeral lateralization and stepwise glenoid lateralization based on the intraoperatively measured glenoid-humeral axis interval (GHI) could improve clinical outcomes compared to consistent lateralization that was assigned irrespective of the GHI. In this study, GHI was measured using the superior approach, but it can also be measured using the deltopectoral approach.
Methods:
Fifty-four patients were treated with nonlateralized inlay-type implants (group A). Forty patients received the same type of inlay rTSA with an 8.0 mm-thick bony-increased offset (group B). Moreover, 50 patients underwent inlay rTSA with glenoid lateralization (Group C), whereas 45 underwent onlay rTSA with humeral lateralization (Group D). Groups C and D were stratified into 3 subgroups based on their GHI-C1 and D1 (GHI <20.0 mm), C2 and D2 (20.0≤ GHI <25.0), and C3 and D3 (GHI ≥26.0). Subgroups C1, C2, and C3 were lateralized to the glenoid side, whereas D1, D2, and D3 were lateralized to the humeral side. Baseline and 2-year postoperative measurements-active anterior elevation; external rotation at 0° arm abduction; external rotation at 90° arm abduction; pain visual analog scale score; Constant score; and University of California, Los Angeles score-were compared between groups.
Results:
The consistent lateralization that was assigned irrespective of GHI (group B) did not improve clinical parameters as compared to the nonlateralization (group A), excluding external rotation at 90° arm abduction (65.9 ± 9.6, P < .001). The both GHI-based lateralization (groups C and D) significantly improved the clinical parameters. The GHI-based glenoid lateralization (Group C) had the highest anterior elevation (146.1° ± 11.2, P = .010), external rotation at 0° arm abduction (44.1° ± 10.6, >0.001), and University of California, Los Angeles score (27.5 ± 2.1, P = .002). The GHI-based humeral lateralization (group D) showed the highest Constant score (67.8 ± 8.2, P = .003).
Conclusion:
The stepwise glenoid and humeral lateralization based on the GHI improved outcomes compared with the nonlateralization or the consistent lateralization that was assigned irrespective of the GHI.
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