Did the surgery correct the glenoid version and decentering? The value of comparable preoperative and postoperative imaging.

 A young athletic man presented with painful glenohumeral arthritis and functional posterior instability of his right shoulder as shown on the axillary "truth" view below (see Answering the critical question: "To what degree is the humeral head functionally centered on the glenoid?" in 6 easy steps.)

The surgical objective was to re-center the humeral head on the glenoid and re-establish durable functional stability of his shoulder. An axillary truth view 5 years after surgery indicated that the surgical objective was achieved. 

This type of assessment can only be made if the preoperative and postoperative imaging modalities and techniques are the same. This point is emphasized by the authors of Total shoulder arthroplasty in patients with a B2 glenoid addressed with corrective reaming: mean 8-year follow-up who used standardized axillary radiographs preoperatively and sequentially postoperatively to assess humeral head decentering relative to the glenoid vault, immediate glenoid seating, and final glenoid peg radiolucency. Interestingly, this plain radiographic study revealed that glenoid component failure was associated with poor initial glenoid component seating, with failed components having an average of 25% of the glenoid component not seated. Preoperative deformity as seen on CT scans, such as glenoid retroversion, inclination, or humeral head subluxation did not predict glenoid component failure.

This straightforward approach for determining the extent to which the procedure achieved the preoperative goal is available to all surgeons, whereas obtaining routine preoperative and sequential postoperative CT scans is impractical in most clinical settings.

Here are some other examples, demonstrating the value of comparable standardized preoperative and postoperative axillary views.

and from Early clinical and radiographic outcomes of anatomic total shoulder arthroplasty with a biconvex posterior augmented glenoid for patients with posterior glenoid erosion: minimum 2-year follow-up

Comment: CT scans and axillary views are not only different imaging modalities, they are also obtained with the arm in different positions. Thus, it is not surprising that they yield different findings for the same shoulder, as shown below.

The point is that if surgeons wish a practical way for evaluating their success in achieving the desired postoperative glenohumeral relationships in comparison to the preoperative pathoanatomy, standardized axiallary views appear to be the best bet. Comparing preoperative CT scans to postoperative axillary views may be a bit like comparing

to

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Here are some videos that are of shoulder interest
Shoulder arthritis - what you need to know (see this link).
How to x-ray the shoulder (see this link).
The ream and run procedure (see this link).
The total shoulder arthroplasty (see this link).
The cuff tear arthropathy arthroplasty (see this link).
The reverse total shoulder arthroplasty (see this link).
The smooth and move procedure for irreparable rotator cuff tears (see this link).
Shoulder rehabilitation exercises (see this link).