What is a distinguishing feature of Walch Classification B1?

The distinguishing feature of Walch Classification B1 is characterized by a posterior subluxed humerus, which is a condition where the humeral head is partially displaced backward relative to the glenoid cavity. This classification highlights the alignment and positioning of the humerus and glenoid joint. In B1, alongside the posterior subluxation, there is typically observed narrowing of the glenohumeral joint space. This aspect is significant for understanding the progression of glenohumeral degeneration, particularly in patients with severe rotator cuff deficiencies or degenerative conditions.

This specific classification emphasizes the importance of evaluating the joint alignment and how it may implicate treatment options or surgical interventions. Identifying these subtleties in joint positioning is crucial for orthopedic specialists when planning total shoulder arthroplasty, as it can influence the choice of prosthetic components and surgical approach.