Monday, August 18, 2025

Recent JBJS article on failures (51%) of anatomic total shoulder arthroplasties

Patients and surgeons are interested in the causes and prevention of shoulder arthroplasty failures. Failures can be viewed in terms of the characteristics of the surgeon, the patient, the shoulder, and type of failure. Regardless of the cause of the failure, it is the patient (not the surgeon or the implant company) that bears the consequences. Thus, in each case we should do our best to determine "what could have been done to prevent the failure experienced by the patient?" In this way, each failure - whether ours or someone else's - becomes a learning opportunity. At an early morning meeting in August 2025, a small group of shoulder surgeons took the first steps in developing a Shoulder Arthroplasty Failure Research (SAFR) program with the goal of learning from individual cases of arthroplasty failure.

The June, 2025 JBJS article, High Failure Rates of Polyethylene Glenoid Components in Stemless Anatomic Total Shoulder Arthroplasty for Primary and Secondary OA, is interesting to consider in this regard.  These components were used in this series


At a mean followup of 72 months, out of 197 patients, over half (101) had failures necessitating surgical revision, 86 because of glenoid component loosening. What might be done to prevent these failures? 


Left:  Intraoperative view following explantation of the polyethylene glenoid with a 4 x 2-cm bone defect. Right: Explanted components with severe glenoid wear and superior glenoid abrasion, with the pegs completely separated from the body of the glenoid component.

Is the problem (as the title might suggest) the use of a stemless humeral component with a polyethylene glenoid component (in which case failures could be avoided by using a stemmed humeral component)? 

Or is it the type of polyethylene glenoid component being used (in which case a different glenoid component design could be used)? 

Or is it the technique by which the glenoid component was inserted (in which case greater attention could be directed at the quality of glenoid component preparation, cementing and seating?). 

These three elements are surgeon-controlled variables (in contrast to patient age, sex, diagnosis, BMI, critical shoulder angle and lateral acromial angle, which were measured in this study but which are of lesser interest in that they are not modifiable by the surgeon). 

So...is the stemless humeral component or the glenoid component the problem? Prior studies of this glenoid component (with either stemless or stemmed humeral components) reported glenoid component loosening rates between 25% and 100% after 5 years when used with either stemless or stemmed humeral components: Univers II shoulder prosthesis: a multicenter, prospective randomized controlled trial and Radiologic midterm results of cemented and uncemented glenoid components in primary osteoarthritis of the shoulder: a matched pair analysis. Perhaps failure could be avoided with a different glenoid component.

Or...might the technique of glenoid component insertion be an issue?



In this 6 week postoperative x-ray from the article there is cement between the back of the glenoid component and the glenoid bone (yellow arrows).  Cement in this location can crack and displace leaving the component unsupported. 
This problem can be avoided by placing the component directly on the properly reamed glenoid bone without interposed cement as shown below.


The other issue shown on this x-ray is the large amount of bone in the glenoid vault surrounding the pegs (red arrow) that prevents bone ingrowth around them.

This problem can be avoided by careful preparation of the glenoid bone with good carpentry so that bone ingrowth is enabled.
Perhaps the risk of failure could be reduced using a different insertion technique






As shown below, this patient experienced glenoid component failure
How could this failure have been prevented?



Comment: This is an example of the type of analysis that we hope to carry out in the Shoulder Arthroplasty Failure Research program. Stay tuned!

Looking to make wise choices



Barred Owl
Union Bay Natural Area
May 2025





Follow on twitter/X: https://x.com/RickMatsen
Follow on facebook: https://www.facebook.com/shoulder.arthritis
Follow on LinkedIn: https://www.linkedin.com/in/rick-matsen-88b1a8133/

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).