This paper proposes a classification system for reverse total shoulder arthroplasty prostheses. Designs are categorized by glenoid center-of-rotation position and humeral offset. The goal is standardized nomenclature that helps surgeons match a prosthesis configuration to a given clinical scenario.
When you pick a reverse shoulder implant, you are really choosing where to put the center of rotation and how far to lateralize the humerus. Remember the two thresholds: glenoid CoR at 5 mm and humeral offset at 15 mm. These define medialized vs lateralized on each side.
Medializing lengthens the deltoid moment arm (easier elevation) but shortens the cuff, flattens deltoid wrapping, and raises scapular notching. Lateralizing does the opposite, improving stability, cuff tension, and notching at the cost of deltoid efficiency and higher acromial stress.
Apply it to the patient in front of you: an MG/MH construct is highly medialized and often needs subscapularis repair for stability, and is discouraged with uncorrected glenoid erosion. For a medially eroded glenoid, lateralize (metal or BIO-RSA bone graft) to restore the joint line.
This is a framework paper, not an outcome trial, and all authors have ties to a manufacturer, so weigh the biomechanical claims as design rationale rather than proven clinical superiority.
This paper proposes a classification system for reverse total shoulder arthroplasty prostheses. Designs are categorized by glenoid center-of-rotation position and humeral offset. The goal is standardized nomenclature that helps surgeons match a prosthesis configuration to a given clinical scenario.
When you pick a reverse shoulder implant, you are really choosing where to put the center of rotation and how far to lateralize the humerus. Remember the two thresholds: glenoid CoR at 5 mm and humeral offset at 15 mm. These define medialized vs lateralized on each side.
Medializing lengthens the deltoid moment arm (easier elevation) but shortens the cuff, flattens deltoid wrapping, and raises scapular notching. Lateralizing does the opposite, improving stability, cuff tension, and notching at the cost of deltoid efficiency and higher acromial stress.
Apply it to the patient in front of you: an MG/MH construct is highly medialized and often needs subscapularis repair for stability, and is discouraged with uncorrected glenoid erosion. For a medially eroded glenoid, lateralize (metal or BIO-RSA bone graft) to restore the joint line.
This is a framework paper, not an outcome trial, and all authors have ties to a manufacturer, so weigh the biomechanical claims as design rationale rather than proven clinical superiority.