Friday, September 28, 2012

The early migration of a partially cemented fluted pegged glenoid component using radiostereometric analysis JSES

JSES recently published: The early migration of a partially cemented fluted pegged glenoid component using radiostereometric analysis

The authors conducted a very careful study using radiostereometric analysis and two-year post op CT scans to track the motion of a glenoid component relative to the glenoid bone in eleven shoulders. They found that focal radiolucency around the central peg as shown on this CT scan
was associated with rapid early migration of the glenoid component in six of the eleven cases. When bone grew into the flutes of the central peg, migration did not occur, but when it did not, the component was at risk for migration.

While the clinical results for these shoulders showed significant improvement over the preoperative ASES, Constant and pain scores, the findings of this study raise concerns about the longevity of the glenoid components. 

The authors point to three other reports that are of interest in this regard, each of which pointed to the lack of bone ingrowth in some cases:

Bone presence between the central peg's radial fins of a partially cemented pegged all poly glenoid component suggest few radiolucencies.

Clinical and radiographic analysis of a partially cemented glenoid implant: five-year minimum follow-up


The findings of the authors of the current JSES report are of concern. I know them to be excellent surgeons; it is doubtful that the results are attributable to technical concerns. The illustrations in the manuscript show excellent positioning of the components.  The patients all had osteoarthritis (not RA) and had an average age of 69 years and that nine of the eleven were women, the point being that the authors' findings can probably not be attributed to inflammatory arthritis or to high levels of physical activity. Yet as the authors point out in referring to In vivo measurement of shoulder joint loads during activities of daily living, the shoulder is a major load-bearing joint even in the absence of 'high levels of physical activity'.



So, because the  glenoid component remains the leading cause of failure, we take time to explain the risk of this complication to patients considering a total shoulder and continue to explore the application of the ream and run procedure for carefully selected patients with osteoarthritis.


----


If you have suggestions for topics you'd like us to address in this blog, please send an email to
shoulderarthritis@uw.edu

Use the "Search the Blog" 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.

See the countries from which our readers come on this post.