Shoulder surgeons often strive to insert the glenoid comonent of an anatomic total shoulder arthroplasty in less than 15 degrees of retroversion. If there is more than 15 degrees of version on preoperative imaging they may attempt version "correction" by reaming of the anterior glenoid bone, posterior bone grafting or using posteriorly augmented glenoiod components. Of course, each of these approaches has its potential downsides: removal of quality bone, failure of graft incorporation, and difficulty seating+increased loosening moment arm, respectively.
CT based preoperative planning is commonly used prior to anatomic arthroplasty to evaluate glenoid version and plan its management. Because of the Projected Lifetime Cancer Risks From Current Computed Tomography Imaging and Computed Tomography for Preoperative Shoulder Arthroplasty Planning: Lifetime Malignancy Risk, it is worth asking whether CT scans are necessary for arthroplasty planning in routine cases (see CT-free arthroplasty planning).
All of the above beg the question "is retroversion of the glenoid component associated with the outcome the patient realizes after anatomic arthroplasty?"
A 2024 article, Does glenoid version and its correction affect outcomes in anatomic shoulder arthroplasty? A systematic review, reviewed 16 studies, including 1211 shoulders and concluded "There is currently insufficient evidence that pre- or postoperative glenoid version influences postoperative outcomes independent of other morphologic factors such as joint line medialization. Given that noncorrective reaming demonstrated favorable postoperative outcomes, and that postoperative glenoid version was not significantly and consistently found to impact outcomes, there is inconclusive evidence that correcting glenoid retroversion is routinely required."
A recent article by different authors, Does Postoperative Glenoid Component Retroversion Following Anatomic Total Shoulder Arthroplasty Affect Clinical Outcomes? A Systematic Review and Meta- Analysis. reviewed 15 English language articles reporting 2-year clinical outcomes and postoperative glenoid version (1190 shoulders). 73% were published in the last 5 years.
346 patients had glenoid component retroversion ≥ 15 degrees (mean 20±4 degrees)
833 patients had glenoid component retroversion < 15 degrees (mean 7.7±4 degrees).
The authors did not find signficant differences between patients with <15 and ≥ 15 degrees of glenoid component retroversion for patient reported outcomes, range of motion, complications or revisions.
When evaluating radiolucencies for shoulders with <15 vs ≥15 degrees of postoperative glenoid component version, shoulders with ≥15 degrees of glenoid component retroversion had less radiolucency: a statistically significantly higher rate of no radiolucency (Lazarus 0 score) (p<0.001). There was no statistically significant difference in the likelihood of a CPG 3 (bone growth within the central-peg flanges) for shoulders with <15 vs ≥15 degrees of postoperative glenoid component version.
Comment: While there may be theoretical arguments for insertion of anatomic glenoid components in <15 degrees of retroversion, the pubished literature does not provide evidence that glenoid component version is associated with the outcome realized by the patient.
It may be that secure glenoid component seating, rather than "correction of glenoid version" is the priority.
Wilson's Snipe
- 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).
