Postoperative radiographic findings of an uncemented convertible short stem for anatomic and reverse shoulder arthroplasty
These authors report the radiographic findings of a press-fit convertible short-stemmed humeral component in 150 anatomic TSAs (group 1) and 77 RSAs (group 2) at a minimum follow-up of 2 years postoperatively. Plain radiographs were reviewed for stem loosening, alignment, signs of stress shielding, and the filling ratio.
At final follow-up, 49% of group 1 and 65% of group 2 had no evidence for radiographic changes. In those with radiographic changes, low bone adaptions were found in 83% and high adaptions in 17% in both groups. Larger stem sizes with higher filling ratios were associated with high radiographic adaptions in both groups (P = .02). The overall filling ratios were higher in group 2 (P = .002). Cortical contact of the stem led to higher bone adaptions (P = .014).
Radiographic changes were associated with a higher filling ratio and cortical contact of the stem.
Comment: These authors point out that bony adaptive changes (such as those shown below) can be seen with short stemmed humeral components.
and component loosening.
Short stemmed humeral components are often described as 'bone preserving". We agree that bone preservation is important, but find that this objective can be achieved with a standard humeral component inserted with impaction grafting - an approach that is at least as bone preserving as with the use of short stemmed implants. Because impaction grafting distributes interface forces over a broad area, a standard length stem without ingrowth surfaces minimizes problems with stress shielding and achieves additional stability through greater bone-prosthesis contact.
=====
These authors report the radiographic findings of a press-fit convertible short-stemmed humeral component in 150 anatomic TSAs (group 1) and 77 RSAs (group 2) at a minimum follow-up of 2 years postoperatively. Plain radiographs were reviewed for stem loosening, alignment, signs of stress shielding, and the filling ratio.
At final follow-up, 49% of group 1 and 65% of group 2 had no evidence for radiographic changes. In those with radiographic changes, low bone adaptions were found in 83% and high adaptions in 17% in both groups. Larger stem sizes with higher filling ratios were associated with high radiographic adaptions in both groups (P = .02). The overall filling ratios were higher in group 2 (P = .002). Cortical contact of the stem led to higher bone adaptions (P = .014).
Radiographic changes were associated with a higher filling ratio and cortical contact of the stem.
Comment: These authors point out that bony adaptive changes (such as those shown below) can be seen with short stemmed humeral components.
To minimize this risk they advise surgeons to achieve fixation with minimal canal filling and cortical contact.
However, in minimizing the fit in the canal, there is also a risk of malalignment
and component loosening.
Short stemmed humeral components are often described as 'bone preserving". We agree that bone preservation is important, but find that this objective can be achieved with a standard humeral component inserted with impaction grafting - an approach that is at least as bone preserving as with the use of short stemmed implants. Because impaction grafting distributes interface forces over a broad area, a standard length stem without ingrowth surfaces minimizes problems with stress shielding and achieves additional stability through greater bone-prosthesis contact.
Compare the amount of bone preserved with this method (seen below) in comparison to that with the short stemmed component (shown above).
=====
We have a new set of shoulder youtubes about the shoulder, check them out at this link.
Be sure to visit "Ream and Run - the state of the art" regarding this radically conservative approach to shoulder arthritis at this link and this link
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 arthritis, total shoulder, ream and run, reverse total shoulder, CTA arthroplasty, and rotator cuff surgery as well as the 'ream and run essentials'
