Overstuffing is not a condition diagnosed on x-ray, rather it is a condition in which there is too much stuff in the available space. Sort of like what Lewis Carroll described in his 1865 children's novel, Alice in Wonderland. After Alice drinks from the bottle labeled "DRINK ME" she expands to where she cannot move.
In a prior post, How to overstuff an anatomic arthroplasty, we presented the origins of the term "overstuffing", its clinical significance, and the different causes. We emphasized that replacing a deformed arthritic humeral head with a round one and inserting a plastic glenoid component in a previously collapsed joint space risks putting the soft tissues around the glenohumeral joint under excessive tension.
A recent paper, How anatomic should anatomic total shoulder arthroplasty be? Evaluation of humeral head reconstruction with the best-fit circle, agreed that "anatomic" total shoulder arthroplasty can risk overstuffing the glenohumeral joint.
The authors evaluated 97 cases of primary glenohumeral osteoarthritis in patients treated with anatomic TSA. Coronal plane CT images in the plane of the humerus were used to determine the circle that fit the proximal humeral anatomy
The amount of thinning of the humeral head was determined as described below.
An anatomic TSA was modeled with an anatomic humeral head with a radius equal to that of the circle combined with a 4-mm polyethylene glenoid component.
For this series of patients the average radius of the best-fit circle was 25 ± 2 mm. There was a mean thinning of 2 ± 2 mm mean percent thinning was 9%.
With the addition of the simulated 4-mm glenoid implant, the humeral head was displaced laterally by a mean of 6 ± 2 mm relative to the preoperative position.
In this study, what appeared to be radiographic overstuffing was not associated with loss of motion, probably because sufficient soft tissue releases were performed.
Comment: Overstuffing not a radiographic measurement on an AP radiograph, it is stiffness of the glenohumeral joint resulting from putting more volume in the joint than the surrounding soft tissues can accommodate.
The good news is that postarthroplasty motion can be assessed while the patient is still on the operating table, before the wound is closed. For this purpose we rely on meeting the "40, 50, 60" guidelines as shown below.
At the end of the case, we like to take a photograph documenting shoulder motion to assure ourselves and the patient that the shoulder "will go".
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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).
