This narrative review maps the unsettled design debates in reverse total shoulder arthroplasty. It addresses three questions: medialized versus lateralized glenosphere, neutral versus inferior baseplate tilt, and 135° versus 155° humerosocket inclination. The goal is to clarify what the literature supports and where consensus is still lacking.
When you see notching on a post-RSA radiograph, recognize it as the classic signature of the medialized Grammont design, driven by humerosocket impingement on the lateral scapular pillar in adduction.
The core mental model is a trade-off. Medialization protects the baseplate but causes notching. Lateralization reduces notching but loads the baseplate, historically causing failure until locking screws changed the equation.
This matters for how you counsel and plan: baseplate placement low on the glenoid, avoiding superior tilt, and a more varus inclination all reduce impingement against the scapular pillar. The one hard rule to carry into the OR is that superior tilt and superior positioning drive early baseplate failure and must be avoided.
Everything else, including medial versus lateral and neutral versus inferior tilt, remains genuinely debated because no Level-I comparisons exist and meta-analyses are confounded by mixed implant variables.
This narrative review maps the unsettled design debates in reverse total shoulder arthroplasty. It addresses three questions: medialized versus lateralized glenosphere, neutral versus inferior baseplate tilt, and 135° versus 155° humerosocket inclination. The goal is to clarify what the literature supports and where consensus is still lacking.
When you see notching on a post-RSA radiograph, recognize it as the classic signature of the medialized Grammont design, driven by humerosocket impingement on the lateral scapular pillar in adduction.
The core mental model is a trade-off. Medialization protects the baseplate but causes notching. Lateralization reduces notching but loads the baseplate, historically causing failure until locking screws changed the equation.
This matters for how you counsel and plan: baseplate placement low on the glenoid, avoiding superior tilt, and a more varus inclination all reduce impingement against the scapular pillar. The one hard rule to carry into the OR is that superior tilt and superior positioning drive early baseplate failure and must be avoided.
Everything else, including medial versus lateral and neutral versus inferior tilt, remains genuinely debated because no Level-I comparisons exist and meta-analyses are confounded by mixed implant variables.