This retrospective cohort followed 77 Delta III reverse shoulder arthroplasties for cuff tear arthropathy or pseudoparesis, minimum 24 months. It asked whether inferior scapular notching hurts clinical outcomes, and which controllable implant-positioning variables predict it. The authors built a notching index from glenosphere height and the prosthesis-scapular neck angle.
When you position the glenosphere in a reverse shoulder, two things you control decide whether notching develops: how high the sphere sits on the glenoid and the angle it makes with the scapular neck. Place it low, with inferior overhang. Height matters roughly eight times more than the angle, so lowering the glenosphere is the highest-yield move.
This paper matters because it showed notching is not just a radiographic curiosity. Notched shoulders had lower Constant scores, weaker strength, and less motion at intermediate follow-up. It also builds on Nyffeler's cadaveric work showing inferior glenosphere placement delays impingement, and it contradicts the DePuy guide-pin recommendation to center the pin regardless of scapular anatomy.
A practical pitfall: avoid excessive medial reaming, which pulls the glenosphere toward the lateral scapular pillar and raises the prosthesis-scapular neck angle.
This retrospective cohort followed 77 Delta III reverse shoulder arthroplasties for cuff tear arthropathy or pseudoparesis, minimum 24 months. It asked whether inferior scapular notching hurts clinical outcomes, and which controllable implant-positioning variables predict it. The authors built a notching index from glenosphere height and the prosthesis-scapular neck angle.
When you position the glenosphere in a reverse shoulder, two things you control decide whether notching develops: how high the sphere sits on the glenoid and the angle it makes with the scapular neck. Place it low, with inferior overhang. Height matters roughly eight times more than the angle, so lowering the glenosphere is the highest-yield move.
This paper matters because it showed notching is not just a radiographic curiosity. Notched shoulders had lower Constant scores, weaker strength, and less motion at intermediate follow-up. It also builds on Nyffeler's cadaveric work showing inferior glenosphere placement delays impingement, and it contradicts the DePuy guide-pin recommendation to center the pin regardless of scapular anatomy.
A practical pitfall: avoid excessive medial reaming, which pulls the glenosphere toward the lateral scapular pillar and raises the prosthesis-scapular neck angle.