This imaging study characterizes the Walch Type C dysplastic glenoid using CT and validated 3D reconstruction software. It quantifies retroversion, depth, surface area, and dysplastic features in the largest cohort reported to date. The goal is to define the anatomy that complicates shoulder arthroplasty in these patients.
The clinical decision rule sits in the neutral glenoid depth. When depth exceeds 15 mm, a traditional polyethylene component can be seated without version correction. Below 15 mm, the vault is too shallow, and you should consider hemiarthroplasty, bone grafting, a mini inset glenoid, or reverse arthroplasty.
The reason retroversion matters is biomechanical. Component retroversion over 10° increases micromotion at the bone-cement interface and drives premature loosening, so failing to recognize a 37° dysplastic glenoid sets up the implant to fail.
The board-relevant distinction is Type C versus B3. Type C retroversion is developmental and uniconcave from birth. B3 retroversion is acquired from posterior erosion. Type C averages 37° versus 24° for B3. Do not rely on the classic textbook triad. Scapular neck deficiency, dentate surface, and widened joint space were each present in a minority here, so their absence does not exclude dysplasia.
This imaging study characterizes the Walch Type C dysplastic glenoid using CT and validated 3D reconstruction software. It quantifies retroversion, depth, surface area, and dysplastic features in the largest cohort reported to date. The goal is to define the anatomy that complicates shoulder arthroplasty in these patients.
The clinical decision rule sits in the neutral glenoid depth. When depth exceeds 15 mm, a traditional polyethylene component can be seated without version correction. Below 15 mm, the vault is too shallow, and you should consider hemiarthroplasty, bone grafting, a mini inset glenoid, or reverse arthroplasty.
The reason retroversion matters is biomechanical. Component retroversion over 10° increases micromotion at the bone-cement interface and drives premature loosening, so failing to recognize a 37° dysplastic glenoid sets up the implant to fail.
The board-relevant distinction is Type C versus B3. Type C retroversion is developmental and uniconcave from birth. B3 retroversion is acquired from posterior erosion. Type C averages 37° versus 24° for B3. Do not rely on the classic textbook triad. Scapular neck deficiency, dentate surface, and widened joint space were each present in a minority here, so their absence does not exclude dysplasia.