Abstract
Orthopedic conditions such as craniosynostosis and osteonecrosis of the femoral head (ONFH) are highly concerning due to their high incidence rates, surgical complexity, and potential for severe postoperative complications. In craniosynostosis surgery, grinding techniques can generate the risk of thermal buildup, which poses a serious threat to surrounding brain or nerve tissues and irreversible complications. In ONFH surgery, it also involves complex procedures (including incision, guide wire insertion, drilling, curettage, and bone implantation), which introduces significant risks such as fractures and recurrent non-traumatic bone necrosis.To address the above issues, three innovative surgical tooling solutions are developed using additive manufacturing techniques in this thesis.
(i) Ceramic hollow grinding tool
For craniosynostosis surgery, the 3D-printed ceramic hollow grinding tool is proposed and fabricated to facilitate the coolant delivery into the bone grinding area, thereby generating more effective cooling performance. The CFD simulation and experiments prove that the new design enables more coolant to reach the surgery zone, limiting the heat accumulation and flushing away removed bone debris. In the in vivo test, the new tool produces less apoptosis and edema area to the rat brain in comparison with that of conventional tools.
(ii) Closed-loop temperature control grinding device
For craniosynostosis surgery, the novel grinding device is proposed to continuously monitor the grinding temperature and precisely apply coolant when needed. The customized grinding tool is created with the embedded temperature sensors and the coolant channels. Our device effectively maintains the grinding surface temperature within the surgeon-defined range, with the latency of less than 1 second. Furthermore, our design not only ensures the coolant spray outlets remain unobstructed by debris during grinding, but also effectively removes debris at the interface. Our design might reduce the risk of potential complications, such as bone hyperplasia.
(iii) Multifunctional ceramic tool
For ONFH surgery, the multifunctional ceramic surgery tool is innovatively designed and additively manufactured for early-stage ONFH treatment. The multifunctional tool can not only act as a drilling tool, but also retain itself in the drilled hole as a bone scaffold. At the meantime, the tool can delivery active ingredient (Vitamin C) for fast recovery. The proposed tool is additively manufactured with the inter-connected pore structures (with the porosity of 50%, 70% and 80%). The tool not only meets required mechanical properties, but also shows drug releasing function with controllable diffusion rates in the experiments. The ceramic tool with Vitamin C coating also enhances cell adhesion and accelerates cell growth based on the osteoblast induction assessment.
The above three designed tools minimize complication occurrence in craniosynostosis and ONFH surgery, opening new opportunities for the development of orthopedic surgical tools using additive manufacturing technology.
| Date of Award | 17 Mar 2025 |
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| Original language | English |
| Awarding Institution |
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| Supervisor | Haonan Li (Supervisor), Kean How Cheah (Supervisor) & Salman Ijaz (Supervisor) |