Augmented glenoid component designs for type B2 erosions: a computational comparison by volume of bone removal and quality of remaining bone

doi:10.1016/j.jse.2014.12.018

Journal of Shoulder and Elbow Surgery

Volume 24, Issue 8, August 2015, Pages 1218-1226

https://doi.org/10.1016/j.jse.2014.12.018 Get rights and content

Background

The purpose of this computational modeling study was to compare the volume of glenoid bone removal required to implant 3 augmented component designs for management of B2 erosions. In addition, we assessed bone quality of the supporting bone directly beneath the implants by measuring bone density and porosity.

Methods

Three augmented component designs—full-wedge, posterior-wedge, and posterior-step—were studied by virtual implantation in a cohort of 16 patients with B2 glenoids. B2 retroversion was corrected to 0° and 10°. The outcome variables were the volume of glenoid bone removal required for implantation and the density and porosity of the bone immediately beneath the implant.

Results

Implant design had a significant effect on the volume of bone removal (P < .001). When correcting to 0°, the posterior-wedge implant removed less bone than the posterior-step (P < .001) and the full-wedge (P = .004). At 10° retroversion, the posterior-wedge removed less bone (P = .029) than the posterior-step but was no different than the full-wedge (P = .143). The residual glenoid bone density with the posterior-wedge was significantly greater than with the posterior-step (P = .048), with no other significant differences (P > .05). Residual glenoid bone porosity was not significantly different between implants (P > .262).

Conclusions

Augmented components can provide a bone-preserving option for B2 glenoid management. Substantial variations in the volume of bone removal and the quality of the remaining glenoid bone were found between 3 different designs of augmented implants. Simulations with the posterior-wedge implant resulted in substantially less glenoid bone removal, with the remaining supporting bone being of better quality.

Section snippets

Augmented implant models

Three augmented glenoid component designs—posterior-step, full-wedge, and posterior-wedge—were created as computer models by computer-aided design (CAD) software (Dassault Systèmes SolidWorks Corporation, Waltham, MA, USA) (Fig. 1). These implant CAD models were created according to the precise dimensions and sizes of augmented implant designs. The posterior-step implant (Steptech; DePuy Synthes, Warsaw, IN, USA) consisted of 5 sizes based on the bearing diameter (40, 44, 48, 52, and 56 mm) and

Volume of bone removal

The choice of implant design had a significant effect on the volume of glenoid bone removal (P < .001) (Fig. 5, A). When using the augmented implants to correct retroversion to an ideal 0°, the posterior-wedge implant removed a mean of 1347 mm³ less total bone than the posterior-step implant (P < .001) and a mean 1010 mm³ less than the full-wedge implant (P = .004). There was no significant difference between the total bone removal of the posterior-step and full-wedge implants (P = .509). When

Discussion

The results of this study indicate that there are substantial differences in the amount of glenoid bone removal required to fully seat different designs of posterior augmented implants. Aside from bone removal, it is apparent that the density and porosity of the remaining supporting bone immediately beneath the implant substantially vary among implant designs. Recent literature has demonstrated that preservation of glenoid subarticular bone is important in resisting implant migration and

Conclusion

Augmented glenoid components provide a bone-preserving surgical option for the management of B2 erosions. Substantial variations in the volume of bone removal and the quality of the remaining glenoid bone were found between 3 different designs of augmented implants. Simulations with the posterior-wedge implant resulted in substantially less glenoid bone removal, with the remaining supporting glenoid bone being of better quality.

Disclaimer

George S. Athwal is a consultant for DePuy Synthes and Tornier Inc. In addition, he has received research support from DePuy Synthes, Tornier Inc., and Exactech for research related to the subject of this article. No company had any input into the study design, protocol, testing, data analysis, or manuscript preparation. All the other authors, their immediate families, and any research foundations with which they are affiliated have not received any financial payments or other benefits from any

Acknowledgment

The authors would like to thank Dr. Melanie Columbus for her assistance with statistical analysis. Nikolas K. Knowles is supported in part by the Joint Motion Program (JuMP), a CIHR Training Program in Musculoskeletal Health Research and Leadership.

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: Institutional Review Board approval was obtained at the University of Western Ontario/St. Joseph's Health Care: No. 104316.

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Basic ScienceAugmented glenoid component designs for type B2 erosions: a computational comparison by volume of bone removal and quality of remaining bone

Background

Methods

Results

Conclusions

Section snippets

Augmented implant models

Volume of bone removal

Discussion

Conclusion

Disclaimer

Acknowledgment

J Shoulder Elbow Surg

J Shoulder Elbow Surg

J Shoulder Elbow Surg

J Shoulder Elbow Surg

J Shoulder Elbow Surg

J Shoulder Elbow Surg

J Shoulder Elbow Surg

J Shoulder Elbow Surg

J Shoulder Elbow Surg

J Shoulder Elbow Surg

Basic Science
Augmented glenoid component designs for type B2 erosions: a computational comparison by volume of bone removal and quality of remaining bone