Comparing outcomes of onlay humeral stem designs in reverse total shoulder arthroplasty: a systematic review.
- 1Henry Ford Health, Detroit, MI, USA.
Abstract
Background
Since the development of the original Grammont implant, reverse shoulder arthroplasty (rTSA) has evolved, with onlay and inlay humeral designs emerging as the 2 main options. Onlay designs have gained popularity due to modularity and adaptability, allowing conversion from anatomic total shoulder arthroplasty to rTSA. While differences in medialization and lateralization of the glenoid and humeral stem have been studied, little is known about the impact of these features in various onlay implants. This systematic review aims to compare the clinical outcomes of lateralized humeral (LH) and medialized humeral (MH) onlay designs in rTSA.Methods
The review followed Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. A comprehensive search was conducted in PubMed, Ovid MEDLINE, Embase, and Web of Science to identify studies comparing clinical outcomes of onlay designs. The primary outcomes of interest were patient-reported outcomes and shoulder range of motion.Results
Of 1,005 studies reviewed, 14 met the inclusion criteria, including 14,427 patients. Range of motion comparisons revealed no significant difference in forward flexion between LH and MH designs (135.08° vs. 137.07°, P = .2929). Similarly, abduction did not significantly differ (113.02° vs. 116.42°, P = .1387). Both internal rotation and external rotation were significantly greater in the LH group (6.62 vs. 5.84, P = .0063) (41.21° vs. 31.94°, P < .0001), respectively. American Shoulder and Elbow Surgeons scores were higher in the LH group (77.89 vs. 75.33, P = .255), though not statistically significant. Visual analog scale pain scores were significantly lower in the LH group (0.724 vs. 1.613, P = .0015). Conversely, the MH group demonstrated significantly higher Constant scores (66.51 vs. 60.37, P < .0001). Complication rates were significantly higher in the MH group (13.8%) compared to the LH group (2.0%) (P < .001; χ² test).Conclusion
The LH and MH configurations for onlay rTSA demonstrate distinct domain-specific advantages. LH implants were associated with significantly lower visual analog scale pain scores (0.724 vs. 1.613; P = .0015), superior internal rotation (6.62 vs. 5.84; P = .0063), and markedly greater external rotation (41.21° vs. 31.94°; P < .0001). However, only the external rotation difference exceeded the Minimal Clinically Important Difference. MH implants demonstrated higher Constant scores (66.51 vs. 60.37; P < .0001), though forward flexion and abduction did not significantly differ between groups. Importantly, complication rates were significantly higher in the MH group (13.8% vs. 2.0%; P < .0001). These nuanced differences underscore the importance of individualized surgical planning.
Related
- Stemmed versus stemless humeral implants in anatomic total shoulder arthroplasty: a systematic review and meta-analysis.
- Long-term outcomes of hemiarthroplasty and anatomic total shoulder arthroplasty for atraumatic humeral head avascular necrosis
- Radiographic view strongly influences detection of humeral component migration after stemless shoulder arthroplasty
- Conservative Treatment with Adjunctive Use of Teriparatide for Periprosthetic Humeral Fractures after Reverse Total Shoulder Arthroplasty: A Report of 6 Cases
- Use of a high-speed pencil-tip burr for removal of well-fixed humeral components in revision shoulder arthroplasty
BibTeX
@article{daher2026comparing,
title = {{Comparing outcomes of onlay humeral stem designs in reverse total shoulder arthroplasty: a systematic review.}},
author = {Nicholas Daher and Mahdi Mazeh and Joshua P Castle and Christopher Nikolopoulos and Kai Zhu and Julio Nerys-Figueroa and Taylor Timoteo and Chimdindu Obinero and Jared M Mahylis and Stephanie Muh},
journal = {JSES reviews, reports, and techniques},
year = {2026},
month = sep,
doi = {10.1016/j.xrrt.2026.100882},
url = {https://europepmc.org/article/MED/42926853},
note = {CC BY-NC-ND},
}
RIS
TY - JOUR
TI - Comparing outcomes of onlay humeral stem designs in reverse total shoulder arthroplasty: a systematic review.
AU - Nicholas Daher
AU - Mahdi Mazeh
AU - Joshua P Castle
AU - Christopher Nikolopoulos
AU - Kai Zhu
AU - Julio Nerys-Figueroa
AU - Taylor Timoteo
AU - Chimdindu Obinero
AU - Jared M Mahylis
AU - Stephanie Muh
PY - 2026
DA - 2026/09/18
JO - JSES reviews, reports, and techniques
DO - 10.1016/j.xrrt.2026.100882
UR - https://europepmc.org/article/MED/42926853
AB - Background Since the development of the original Grammont implant, reverse shoulder arthroplasty (rTSA) has evolved, with onlay and inlay humeral designs emerging as the 2 main options. Onlay designs have gained popularity due to modularity and adaptability, allowing conversion from anatomic total shoulder arthroplasty to rTSA. While differences in medialization and lateralization of the glenoid and humeral stem have been studied, little is known about the impact of these features in various onlay implants. This systematic review aims to compare the clinical outcomes of lateralized humeral (LH) and medialized humeral (MH) onlay designs in rTSA.Methods The review followed Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. A comprehensive search was conducted in PubMed, Ovid MEDLINE, Embase, and Web of Science to identify studies comparing clinical outcomes of onlay designs. The primary outcomes of interest were patient-reported outcomes and shoulder range of motion.Results Of 1,005 studies reviewed, 14 met the inclusion criteria, including 14,427 patients. Range of motion comparisons revealed no significant difference in forward flexion between LH and MH designs (135.08° vs. 137.07°, P = .2929). Similarly, abduction did not significantly differ (113.02° vs. 116.42°, P = .1387). Both internal rotation and external rotation were significantly greater in the LH group (6.62 vs. 5.84, P = .0063) (41.21° vs. 31.94°, P < .0001), respectively. American Shoulder and Elbow Surgeons scores were higher in the LH group (77.89 vs. 75.33, P = .255), though not statistically significant. Visual analog scale pain scores were significantly lower in the LH group (0.724 vs. 1.613, P = .0015). Conversely, the MH group demonstrated significantly higher Constant scores (66.51 vs. 60.37, P < .0001). Complication rates were significantly higher in the MH group (13.8%) compared to the LH group (2.0%) (P < .001; χ² test).Conclusion The LH and MH configurations for onlay rTSA demonstrate distinct domain-specific advantages. LH implants were associated with significantly lower visual analog scale pain scores (0.724 vs. 1.613; P = .0015), superior internal rotation (6.62 vs. 5.84; P = .0063), and markedly greater external rotation (41.21° vs. 31.94°; P < .0001). However, only the external rotation difference exceeded the Minimal Clinically Important Difference. MH implants demonstrated higher Constant scores (66.51 vs. 60.37; P < .0001), though forward flexion and abduction did not significantly differ between groups. Importantly, complication rates were significantly higher in the MH group (13.8% vs. 2.0%; P < .0001). These nuanced differences underscore the importance of individualized surgical planning.
SN - 2666-6391
ER -