Background
In 2025, it has been predicted that approximately 175,000 shoulder arthroplasties will be performed.4 Reverse total shoulder arthroplasty continues to grow in popularity, and indications continue to increase. Due to the increasing incidence of this procedure, more attention is being focused on optimizing implant selection and patient outcomes. It has been demonstrated that increased glenosphere size may increase external rotation and may even decrease revision rates.2,3 However, proper glenosphere size selection for each individual patient remains to be fully understood and optimized. The article by Patterson et al focuses on patient factors to help optimize glenosphere selection in reverse total shoulder arthroplasty.1
Article Summary
This article is a retrospective review of one surgeon’s patients undergoing reverse total shoulder arthroplasty from the period of 2020 to 2023. The patients included only had the diagnosis of rotator cuff arthropathy. Those indicated for a reverse shoulder arthroplasty for glenohumeral osteoarthritis, proximal humerus fracture, or revision shoulder arthroplasty were excluded. In total, 118 patients met inclusion criteria. All of these patients had a preoperative CT scan. Measured radiographic parameters included maximal glenoid height, maximal glenoid width, and glenoid version, which were measured independently by two fellowship trained shoulder and elbow surgeons. Patient variables collected included gender, height, weight, and age. Linear regression was then used to model glenoid height and width with patient factors. Those with P values less than or equal to 0.2 were then placed into multivariable models which could predict glenoid sizes based on patient factors.
The results demonstrated that male gender, increased height, and increased weight all correlated with larger glenoid size. With regards to glenoid width, there was a stronger correlation with patient height than patient gender (r2 0.59 vs 0.56). For glenoid height, patient gender had a stronger correlation than patient height (r2 0.41 vs 0.37). Of the male patients included, 76% received a 39mm glenoid while 5% received a 36mm glenoid. Of the female patients included, 90% received a 36mm glenoid while 7% received a 33mm glenoid.
Commentary
This article underscores the paucity of data on optimal glenosphere size selection. Currently, surgeons often use a gender-based heuristic of using larger glenosphere size on male patients and a smaller size on female patients. While this study confirmed that male gender, in general, did correlate with having a larger glenoid, patient height correlated more strongly with the width of the glenoid than gender alone. It should be noted, however, that the difference between the male predictive model versus the height predictive model was not significantly different. The author also gives examples of similar glenoid sizes in male and female patients resulting in different glenosphere size choice, which reflects the limitations of a gender-based heuristic in this decision process. While further research is needed in order to determine how to optimize glenoid size for patients, the results of this study suggest that patient height in addition to gender may be useful selection criteria for shoulder arthroplasty surgeons.
Citations
- Patterson BM, Galvin JW, Bozoghlian MF, et al. Gender bias in glenosphere size selection in reverse total shoulder arthroplasty: Glenoid size correlates with height and weight, not just gender. .JSES International.; 2025;9:466–471.
- Page R, Beazley J, Graves S, et al. Effect of glenosphere size on reverse shoulder arthroplasty revision rate: An analysis from the Australian Orthopaedic Association National Joint Replacement Registry (AOANJRR). .Journal of Shoulder and Elbow Surgery.; 2022;31.
- Mollon B, Mahure SA, Roche CP, Zuckerman JD. Impact of glenosphere size on clinical outcomes after reverse total shoulder arthroplasty: An analysis of 297 shoulders. .Journal of Shoulder and Elbow Surgery.; 2016;25:763–771.
- Wagner ER, Farley KX, Higgins I, et al. The incidence of shoulder arthroplasty: Rise and future projections compared with hip and knee arthroplasty. .Journal of Shoulder and Elbow Surgery.; 2020;29:2601–2609.