This cross-sectional diagnostic study tested whether a standardized axillary radiograph can characterize arthritic glenohumeral anatomy before and after arthroplasty. It measured glenoid type, version, and glenohumeral contact in 344 arthritic shoulders and 128 ream and run shoulders. The goal was to see if plain film could replace routine preoperative CT.
When you evaluate an arthritic shoulder for arthroplasty, the three things that drive glenoid component failure are retroversion, biconcavity, and posterior subluxation. This paper shows a standardized axillary view captures all three reliably, with a weighted kappa of 0.859 for Walch type even when read by a resident.
The practical rule: for a primary arthroplasty, a well-positioned axillary radiograph is usually sufficient. You do not need routine CT, which adds over $1000 and roughly 26 times the radiation without proven outcome benefit. Learn the Walch classification cold. Type A is centered (A1 no erosion, A2 medial erosion). Type B is posteriorly eroded (B1 displacement, B2 biconcavity).
Remember that version and subluxation are only weakly linked (R² around 0.10), so assess contact position separately rather than assuming a retroverted glenoid means a posteriorly subluxated head.
This cross-sectional diagnostic study tested whether a standardized axillary radiograph can characterize arthritic glenohumeral anatomy before and after arthroplasty. It measured glenoid type, version, and glenohumeral contact in 344 arthritic shoulders and 128 ream and run shoulders. The goal was to see if plain film could replace routine preoperative CT.
When you evaluate an arthritic shoulder for arthroplasty, the three things that drive glenoid component failure are retroversion, biconcavity, and posterior subluxation. This paper shows a standardized axillary view captures all three reliably, with a weighted kappa of 0.859 for Walch type even when read by a resident.
The practical rule: for a primary arthroplasty, a well-positioned axillary radiograph is usually sufficient. You do not need routine CT, which adds over $1000 and roughly 26 times the radiation without proven outcome benefit. Learn the Walch classification cold. Type A is centered (A1 no erosion, A2 medial erosion). Type B is posteriorly eroded (B1 displacement, B2 biconcavity).
Remember that version and subluxation are only weakly linked (R² around 0.10), so assess contact position separately rather than assuming a retroverted glenoid means a posteriorly subluxated head.