Determining the ideal osteotomy for stemless total shoulder replacement – a cadaveric study

McClelland, Damian; Blackwell, John R.; O’Beirne, Sarah; Grocott, Natalie E.; Ogrodnik, Peter

Abstract

Hypothesis: To determine the angle of osteotomy that produces a circular humeral cut surface.
Methods: 49 cadaveric shoulders, from 25 cadavers, underwent sequential humeral head osteotomy from 180 degrees (vertical, in line with the humeral diaphyseal shaft) in 10-degree increments, until the rotator cuff insertion was encountered. At each stage the antero10 posterior and the supero-inferior distances were recorded. The data was analyzed for normality and then assessed to determine the optimum cut angle.
Results: The AP/SI ratio is an indication of roundness. Plotting values of 1-AP/SI (i.e. error) versus cut angle allows us to plot the likelihood of producing a circular cut surface using a third order curve which created the best fit to the data set (R2 = 0.99). The results from this study suggest that the optimum osteotomy angle that produces a circular cut surface is 23 degrees from the vertical. The cohort data illustrates that at this angle the average roundness error is 1% with a 95% confidence limit of less than 1%. There is no significant difference (p>0.05) between genders.
Conclusion: The humeral head shape changes from an oval to circular, and then to an oval cut surface as the osteotomy angle increases from the vertical towards the horizontal. The range of angles within which the cut surface is circular, within 10% error, is degrees from the vertical, which is much less than the traditional osteotomy angle of 45 degrees.

Citation

McClelland, D., Blackwell, J. R., O’Beirne, S., Grocott, N. E., & Ogrodnik, P. (2022). Determining the ideal osteotomy for stemless total shoulder replacement – a cadaveric study. Journal of Shoulder and Elbow Surgery, 31(2), 413-419. https://doi.org/10.1016/j.jse.2021.08.018

• Journal Article Type: Article
• Acceptance Date: Aug 11, 2021
• Online Publication Date: Sep 21, 2021
• Publication Date: 2022-02
• Journal: Journal of Shoulder and Elbow Surgery
• Print ISSN: 1058-2746
• Publisher: Elsevier
• Peer Reviewed: Peer Reviewed
• Volume: 31
• Issue: 2
• Pages: 413-419
• DOI: https://doi.org/10.1016/j.jse.2021.08.018
• Keywords: Humeral replacement; stemless replacement; humeral osteotomy
• Publisher URL: https://www.jshoulderelbow.org/article/S1058-2746(21)00671-6/pdf#relatedArticles