This biomechanical study tested how glenoid baseplate tilt affects stability in the reverse shoulder prosthesis. Baseplates were implanted at 15° inferior, 0°, and 15° superior tilt on polyurethane blocks, then loaded through simulated abduction. The question: which tilt angle best resists micromotion and distributes force at the bone-implant interface?
When you position a reverse shoulder glenoid baseplate, aim for roughly 15° of inferior tilt. This paper gives the biomechanical why: inferior tilt produced the most uniform compression and the least micromotion, both of which protect the bone-implant interface and promote bony ingrowth.
The key mental model is that the glenoid component has a moment arm. Superior tilt increases the torque and shifts load unevenly, so the inferior baseplate lost compression entirely and superior forces tripled.
Excess micromotion (above roughly 100–150 µm) produces a fibrous membrane instead of bone, driving early loosening. Every configuration here stayed under 60 µm, but inferior tilt had the widest margin.
Remember the context: scapular notching plagued 63.6% of Grammont-style reverses, so lateralizing the center of rotation helps, but it lengthens the moment arm and demands sound baseplate positioning. This is a Sawbones model without muscle or capsule forces, so absolute numbers do not translate directly in vivo.
This biomechanical study tested how glenoid baseplate tilt affects stability in the reverse shoulder prosthesis. Baseplates were implanted at 15° inferior, 0°, and 15° superior tilt on polyurethane blocks, then loaded through simulated abduction. The question: which tilt angle best resists micromotion and distributes force at the bone-implant interface?
When you position a reverse shoulder glenoid baseplate, aim for roughly 15° of inferior tilt. This paper gives the biomechanical why: inferior tilt produced the most uniform compression and the least micromotion, both of which protect the bone-implant interface and promote bony ingrowth.
The key mental model is that the glenoid component has a moment arm. Superior tilt increases the torque and shifts load unevenly, so the inferior baseplate lost compression entirely and superior forces tripled.
Excess micromotion (above roughly 100–150 µm) produces a fibrous membrane instead of bone, driving early loosening. Every configuration here stayed under 60 µm, but inferior tilt had the widest margin.
Remember the context: scapular notching plagued 63.6% of Grammont-style reverses, so lateralizing the center of rotation helps, but it lengthens the moment arm and demands sound baseplate positioning. This is a Sawbones model without muscle or capsule forces, so absolute numbers do not translate directly in vivo.