Time-elapsed microstructural imaging of failure of the reverse shoulder implant
Abstract Background Reverse Shoulder Arthroplasties (RSA) have become a primary choice for improving shoulder function and pain. However, the biomechanical failure mechanism of the humeral component is still unclear. The present study reports a novel protocol for microstructural imaging of the entir...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
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BMC
2024-03-01
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| Series: | Journal of Orthopaedic Surgery and Research |
| Subjects: | |
| Online Access: | https://doi.org/10.1186/s13018-024-04652-9 |
| _version_ | 1797259156922564608 |
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| author | Saulo Martelli Egon Perilli Xiaolong Fan Sophie Rapagna Ashish Gupta |
| author_facet | Saulo Martelli Egon Perilli Xiaolong Fan Sophie Rapagna Ashish Gupta |
| author_sort | Saulo Martelli |
| collection | DOAJ |
| description | Abstract Background Reverse Shoulder Arthroplasties (RSA) have become a primary choice for improving shoulder function and pain. However, the biomechanical failure mechanism of the humeral component is still unclear. The present study reports a novel protocol for microstructural imaging of the entire humerus implant under load before and after fracture. Methods A humerus specimen was obtained from a 75-year-old male donor. An expert surgeon implanted the specimen with a commonly used RSA implant (Aequalis reversed II, Stryker Orthopaedics, USA) and surgical procedure. The physiological glenohumeral contact force that maximized the distal implant migration was selected from a public repository ( orthoload.com ). Imaging and concomitant mechanical testing were performed using a large-volume micro-CT scanner (Nikon XT H 225 ST) and a custom-made compressive stage. Both when intact and once implanted, the specimen was tested under a pre-load and by imposing a constant deformation causing a physiological reaction load (650 N, 10 degrees adducted). The deformation of the implanted specimen was then increased up to fracture, which was identified by a sudden drop of the reaction force, and the specimen was then re-scanned. Results The specimen’s stiffness decreased from 874 N/mm to 464 N/mm after implantation, producing movements of the bone-implant interface consistent with the implant’s long-term stability reported in the literature. The micro-CT images displayed fracture of the tuberosity, caused by a combined compression and circumferential tension, induced by the distal migration of the implant. Conclusion The developed protocol offers detailed information on implant mechanics under load relative to intact conditions and fracture, providing insights into the failure mechanics of RSA implants. This protocol can be used to inform future implant design and surgical technique improvements. |
| first_indexed | 2024-04-24T23:04:57Z |
| format | Article |
| id | doaj.art-8019a53d83da48e1954353f4f052cbcd |
| institution | Directory Open Access Journal |
| issn | 1749-799X |
| language | English |
| last_indexed | 2024-04-24T23:04:57Z |
| publishDate | 2024-03-01 |
| publisher | BMC |
| record_format | Article |
| series | Journal of Orthopaedic Surgery and Research |
| spelling | doaj.art-8019a53d83da48e1954353f4f052cbcd2024-03-17T12:32:51ZengBMCJournal of Orthopaedic Surgery and Research1749-799X2024-03-0119111210.1186/s13018-024-04652-9Time-elapsed microstructural imaging of failure of the reverse shoulder implantSaulo Martelli0Egon Perilli1Xiaolong Fan2Sophie Rapagna3Ashish Gupta4School of Mechanical Medical and Process Engineering, Queensland University of TechnologyMedical Devices Research Institute, College of Science and Engineering, Flinders UniversitySchool of Mechanical Medical and Process Engineering, Queensland University of TechnologyMedical Devices Research Institute, College of Science and Engineering, Flinders UniversityGreenslopes Private HospitalAbstract Background Reverse Shoulder Arthroplasties (RSA) have become a primary choice for improving shoulder function and pain. However, the biomechanical failure mechanism of the humeral component is still unclear. The present study reports a novel protocol for microstructural imaging of the entire humerus implant under load before and after fracture. Methods A humerus specimen was obtained from a 75-year-old male donor. An expert surgeon implanted the specimen with a commonly used RSA implant (Aequalis reversed II, Stryker Orthopaedics, USA) and surgical procedure. The physiological glenohumeral contact force that maximized the distal implant migration was selected from a public repository ( orthoload.com ). Imaging and concomitant mechanical testing were performed using a large-volume micro-CT scanner (Nikon XT H 225 ST) and a custom-made compressive stage. Both when intact and once implanted, the specimen was tested under a pre-load and by imposing a constant deformation causing a physiological reaction load (650 N, 10 degrees adducted). The deformation of the implanted specimen was then increased up to fracture, which was identified by a sudden drop of the reaction force, and the specimen was then re-scanned. Results The specimen’s stiffness decreased from 874 N/mm to 464 N/mm after implantation, producing movements of the bone-implant interface consistent with the implant’s long-term stability reported in the literature. The micro-CT images displayed fracture of the tuberosity, caused by a combined compression and circumferential tension, induced by the distal migration of the implant. Conclusion The developed protocol offers detailed information on implant mechanics under load relative to intact conditions and fracture, providing insights into the failure mechanics of RSA implants. This protocol can be used to inform future implant design and surgical technique improvements.https://doi.org/10.1186/s13018-024-04652-9Reverse shoulder arthroplastyImplant failureBone microstructural imagingBiomechanics |
| spellingShingle | Saulo Martelli Egon Perilli Xiaolong Fan Sophie Rapagna Ashish Gupta Time-elapsed microstructural imaging of failure of the reverse shoulder implant Journal of Orthopaedic Surgery and Research Reverse shoulder arthroplasty Implant failure Bone microstructural imaging Biomechanics |
| title | Time-elapsed microstructural imaging of failure of the reverse shoulder implant |
| title_full | Time-elapsed microstructural imaging of failure of the reverse shoulder implant |
| title_fullStr | Time-elapsed microstructural imaging of failure of the reverse shoulder implant |
| title_full_unstemmed | Time-elapsed microstructural imaging of failure of the reverse shoulder implant |
| title_short | Time-elapsed microstructural imaging of failure of the reverse shoulder implant |
| title_sort | time elapsed microstructural imaging of failure of the reverse shoulder implant |
| topic | Reverse shoulder arthroplasty Implant failure Bone microstructural imaging Biomechanics |
| url | https://doi.org/10.1186/s13018-024-04652-9 |
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