This review examines lateralization strategies in reverse shoulder arthroplasty. It contrasts the original medialized Grammont design with modern glenoid-sided, humeral-sided, and global bipolar lateralization. It weighs the biomechanical advantages and risks of each approach and how much to lateralize.
When a patient needs external rotation restored, glenoid-sided lateralization is your most powerful lever: it raised active ER to 46° vs 24° and can restore function in combined loss of elevation and external rotation without a tendon transfer.
But lateralization is a trade-off, not a free win. Glenoid lateralization shortens the deltoid abduction moment arm and raises acromial stress 17.2% at 10 mm, driving scapular spine fracture risk. The practical mental model the authors offer: lateralize the glenoid for its notching and rotation benefits, then compensate by medializing the humerus to offload the acromion.
Know the notching numbers cold for boards: up to 96% pre-2010, now 10–30%, and glenoid lateralization drops it to 5.4% vs 44.9%. Watch for overstuffing in small patients (glenoid best-fit sphere under 30 mm) and cap lateralization around 5–10 mm depending on bone stock.
This review examines lateralization strategies in reverse shoulder arthroplasty. It contrasts the original medialized Grammont design with modern glenoid-sided, humeral-sided, and global bipolar lateralization. It weighs the biomechanical advantages and risks of each approach and how much to lateralize.
When a patient needs external rotation restored, glenoid-sided lateralization is your most powerful lever: it raised active ER to 46° vs 24° and can restore function in combined loss of elevation and external rotation without a tendon transfer.
But lateralization is a trade-off, not a free win. Glenoid lateralization shortens the deltoid abduction moment arm and raises acromial stress 17.2% at 10 mm, driving scapular spine fracture risk. The practical mental model the authors offer: lateralize the glenoid for its notching and rotation benefits, then compensate by medializing the humerus to offload the acromion.
Know the notching numbers cold for boards: up to 96% pre-2010, now 10–30%, and glenoid lateralization drops it to 5.4% vs 44.9%. Watch for overstuffing in small patients (glenoid best-fit sphere under 30 mm) and cap lateralization around 5–10 mm depending on bone stock.