stemless components are thought by some authors to reduce the risk of periprosthetic fractures, loss of bone stock, osteolysis, malalignment, and stress-shielding.
However, as pointed out in Glenohumeral osteoarthritis - what type of arthroplasty has the lowest 10 year revision rate?, data from the large Australian Orthopaedic Association's National Joint Replacement Registry fail to indicate a lower revision rate for stemless ("mid-head") humeral implants in comparison to conventional stemmed implants when both are used with cross-linked polyethylene glenoid components, or as the authors state, "when taking into account the type of polyethylene glenoid component, short or mid stemmed aTSA were not confirmed to have a lower revision rate than long stem implants."
Furthermore, the concern about fractures with conventional stemmed humeral implants is not supported by the data from this registry which show a 12 year fracture rate of only a small fraction of a percent:
To further investigate the possible advantages of a stemless humeral component, the authors of Outcomes Between Stemmed and Stemless Total Shoulder Arthroplasty: A Systematic Review and Meta-analysis of Randomized Controlled Trials compared the clinical outcomes of stemmed versus stemless TSA in randomized controlled trials.
They found 4 studies appropriate for analysis that included the results of 229 stemmed and 358 stemless TSAs.
TSA with stemless versus stemmed humeral components was not associated with notable differences in functional and clinical outcomes.
No difference was observed between stemmed and stemless designs in postoperative forward flexion, abduction, or external rotation. Similarly, there was no difference in the change in forward flexion or external rotation.
No differences were observed between stemmed and stemless designs in the rate of humeral fracture or risk of revision.
The authors of a similar study, Stemless Versus Stemmed Anatomic Total Shoulder Arthroplasty: A Meta-Analysis of Randomized Clinical Studies at Short Term Follow-up, came to the same conclusions: there was no significant difference between stemless and stemmed TSA for the
(1) adjusted Constant-Murley score or pooled functional patient reported outcomes
(2) range of motion outcomes
(3) odds of periprosthetic fractures or radiolucency related to the humeral implant
(4) odds of migration/subluxation of humeral components, infection rate, conversion to reverse TSA, or revision surgery.
Comment: While there is understandable surgeon and industrial interest in new innovations of component design, it also of importance to explore methods by which the purported concerns regarding the legacy standard stem might be addressed. For example, it is recognized that press fit stems may be difficult to seat properly and attempts at fully seating them may result in intraoperative fracture.
By contrast, the authors of Radiographic outcomes of impaction-grafted standard-length humeral components in total shoulder and ream-and-run arthroplasty: is stress shielding an issue? point out that the risks of fracture and stress-shielding can be minimized by using a thinner standard length stem fixed with impaction autografting.
You can support cutting edge shoulder research that is leading to better care for patients with shoulder problems, click on this link.
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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).
By contrast, the authors of Radiographic outcomes of impaction-grafted standard-length humeral components in total shoulder and ream-and-run arthroplasty: is stress shielding an issue? point out that the risks of fracture and stress-shielding can be minimized by using a thinner standard length stem fixed with impaction autografting.
You can support cutting edge shoulder research that is leading to better care for patients with shoulder problems, click on this link.
To add this blog to your reading list in Google Chrome, click on the reading list icon
Follow on twitter: https://twitter.com/shoulderarth
Follow on facebook: click on this link
Follow on facebook: https://www.facebook.com/frederick.matsen
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).
