Osteosarcoma is the most common type of bone cancer in dogs, affecting mainly the distal radius. Limb-sparing surgery using commercial metal plates is one of the available treatments, but often does not yield optimal results. This study proposes the use of personalized endoprostheses and cutting guides produced by additive manufacturing to improve this type of surgery.
The bone models derived from the patient's CT scans are reconstructed and used to design the prosthesis and the cutting guide following the veterinary surgeon’s guidelines. The prosthesis is manufactured of a titanium alloy on a laser powder bed fusion system, while the cutting guide is created of ABS plastic by fused deposition modeling. Several post-treatment steps are performed prior to shipping of the prosthesis-guide kit for surgery. The time required for this approach is on average between 65 and 85 hours. Such an approach can reduce the duration of the surgery by 25-50%.
To verify the resistance of the personalized endoprosthesis, a numerical model of an instrumented limb is developed and validated by an ex-vivo biomechanical test. The validated model is used to analyze the stress distribution in the bones and the implant, and can be used to optimize the personalized endoprosthesis in terms of design and manufacturing material. A comparison of the biomechanical tests of cadaveric limbs instrumented with a personalized endoprosthesis and a commercial plate shows similar behavior of the two assemblies. This suggests that the personalized endoprosthesis is at least as strong as its commercially available counterparts.
Five dogs are successfully implanted during the ongoing clinical trial. The time distribution analysis of these five cases identifies bottlenecks in the production workflow and potential solutions are presented. The cost analysis shows that the customized prosthesis is 70-100% more expensive than a commercial plate-endoprosthesis assembly, however, the reduction in surgery duration and the potential reduction in postoperative infection risks and implant failure risks are non-negligible benefits.
| Date | 21 Sept 2018 |
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| Original language | French |
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| Awarding Institution | - École de technologie supérieure
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| Supervisor | Vladimir Brailovski (Supervisor) & Yvan Petit (Co-supervisor) |
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Timercan, A. (Author),
Brailovski (Supervisor) &
Petit (Co-supervisor),
21 Sept 2018Student thesis: Master's thesis › Master in Engineering: Mechanical Engineering