This In Brief reviews the Walch classification of glenoid morphology in primary glenohumeral osteoarthritis. It uses axial CT to sort glenoids into Types A, B, and C based on version and posterior humeral head subluxation. The article covers the system's origin, subtypes, validation studies, and its known reliability limitations.
When you read a preoperative shoulder CT before arthroplasty, the Walch type tells you what the glenoid will do under a prosthesis. Type A tolerates a standard anatomic component. Type B with posterior wear and subluxation is the danger pattern: eccentric loading drives the rocking-horse effect and glenoid loosening.
That is why B2 and C glenoids push surgeons toward augmented components, corrective reaming, or reverse arthroplasty rather than a standard component in retroversion. Know the reliability caveat for boards and practice: the original system agrees well within a single reader but only fair-to-moderate between readers, largely because of B-versus-C overlap and 2-D CT limits.
The modified classification and 3-D reconstructions improve agreement and add B3 and D subtypes. When your read hinges on B2 versus C, trust CT over MRI, since MRI misses biconcavity.
This In Brief reviews the Walch classification of glenoid morphology in primary glenohumeral osteoarthritis. It uses axial CT to sort glenoids into Types A, B, and C based on version and posterior humeral head subluxation. The article covers the system's origin, subtypes, validation studies, and its known reliability limitations.
When you read a preoperative shoulder CT before arthroplasty, the Walch type tells you what the glenoid will do under a prosthesis. Type A tolerates a standard anatomic component. Type B with posterior wear and subluxation is the danger pattern: eccentric loading drives the rocking-horse effect and glenoid loosening.
That is why B2 and C glenoids push surgeons toward augmented components, corrective reaming, or reverse arthroplasty rather than a standard component in retroversion. Know the reliability caveat for boards and practice: the original system agrees well within a single reader but only fair-to-moderate between readers, largely because of B-versus-C overlap and 2-D CT limits.
The modified classification and 3-D reconstructions improve agreement and add B3 and D subtypes. When your read hinges on B2 versus C, trust CT over MRI, since MRI misses biconcavity.