This prospective multicenter study asked whether scapular notching harms outcomes after inverted-bearing reverse total shoulder arthroplasty (IB-RTSA), a design with a polyethylene glenosphere and metal humeral liner. It followed 270 patients (284 shoulders) for up to 7 years, comparing shoulders with and without notching on function, complications, revisions, and implant survival.
Notching means different things depending on the bearing. In conventional Grammont RTSA, notching reflects polyethylene wear against bone, which drives osteolysis and can loosen the glenoid, so it is a warning sign. In inverted-bearing RTSA the humeral liner is metal, so the notch is a purely mechanical bone indent with sclerotic margins and no PE debris to trigger osteolysis.
That is why this cohort showed equal function, complications, revisions, and 10-year survival regardless of notching. On a follow-up radiograph after IB-RTSA, a low-grade notch with clean sclerotic borders that does not extend toward the baseplate can be treated as a benign finding, not a reason to intervene.
Remember the design tradeoff: medialized designs notch more (up to 94%), lateralized designs notch less (~10-15%), and IB-RTSA falls in between at 35% but without the clinical penalty. This is Level IV evidence with no control group, so weight it accordingly.
This prospective multicenter study asked whether scapular notching harms outcomes after inverted-bearing reverse total shoulder arthroplasty (IB-RTSA), a design with a polyethylene glenosphere and metal humeral liner. It followed 270 patients (284 shoulders) for up to 7 years, comparing shoulders with and without notching on function, complications, revisions, and implant survival.
Notching means different things depending on the bearing. In conventional Grammont RTSA, notching reflects polyethylene wear against bone, which drives osteolysis and can loosen the glenoid, so it is a warning sign. In inverted-bearing RTSA the humeral liner is metal, so the notch is a purely mechanical bone indent with sclerotic margins and no PE debris to trigger osteolysis.
That is why this cohort showed equal function, complications, revisions, and 10-year survival regardless of notching. On a follow-up radiograph after IB-RTSA, a low-grade notch with clean sclerotic borders that does not extend toward the baseplate can be treated as a benign finding, not a reason to intervene.
Remember the design tradeoff: medialized designs notch more (up to 94%), lateralized designs notch less (~10-15%), and IB-RTSA falls in between at 35% but without the clinical penalty. This is Level IV evidence with no control group, so weight it accordingly.