Saturday, February 9, 2013

Radiographs after total shoulder

Accuracy and reliability of postoperative radiographic measurements of glenoid anatomy and relationships in patients with total shoulder arthroplasty

The authors compared x-rays and CT scans in 32 shoulders having total shoulder replacement. They found that the humero-glenoid alignment in the coronal superior-inferior plane and glenoid version showed fair-moderate agreement between x-rays and CT scans. However,  humero-glenoid alignment in the axial anterior-posterior plane, and humero-scapular alignment in the axial plane showed poor agreement between the two methods.

While the paper suggests that it is comparing x-rays to a 'gold standard' CT scan, this is not completely the case.  The axillary view was taken with the patient supine, with the arm in abduction, and the imaging plate superior to the shoulder and the x-ray beam oriented into the axilla perpendicular to the imaging plate. By contrast, the CT scans were done with the patient supine, with the arm at the patient’s side. Thus the arm was not in the same position, compromising comparison. Even among the axillary views the position of the arm was inconstant as shown in their figures, one showing abduction in the plane of the scapula 

and one showing abduction in extension
each with different relationships between the scapula and the x-ray beam.

We have found that if plain axillary x-rays are taken with well controlled positioning and technique, they are extremely useful for determining glenoid version and the anteroposterior position of the humeral head relative to the glenoid.


Use the "Search" box to the right to find other topics of interest to you.

You may be interested in some of our most visited web pages including:shoulder arthritis, total shoulder, ream and runreverse total shoulderCTA arthroplasty,  and rotator cuff surgery.