Heat Sterilization Effects on Polymeric, FDM-Optimized Orthopedic Cutting Guide for Surgical Procedures

Abstract

Improvements in software for image analysis have enabled advances in both medical and engineering industries, including the use of medical analysis tools to recreate internal parts of the human body accurately. A research analysis found that FDM-sourced elements have shown viability for a customized and reliable approach in the orthopedics field. Three-dimensional printing has allowed enhanced accuracy of preoperative planning, leading to reduced surgery times, fewer unnecessary tissue perforations, and fewer healing complications. Furthermore, using custom tools chosen for each procedure has shown the best results. Bone correction-related surgeries require customized cutting guides for a greater outcome. This study aims to assess the biopolymer-based tools for surgical operations and their ability to sustain a regular heat-sterilization cycle without compromising the geometry and fit characteristics for a proper procedure. To achieve this, a DICOM and FDM methodology is proposed for fast prototyping of the cutting guide by means of 3D engineering. A sterilization test was performed on HTPLA, PLA, and nylon polymers. As a result, the unique characteristics within the regular autoclave sterilization process allowed regular supplied PLA to show there were no significant deformations, whilst annealed HTPLA proved this material’s capability of sustaining repeated heat cycles due to its crystallization properties. Both of these proved that the sterilization procedures do not compromise the reliability of the part, nor the safety of the procedure. Therefore, prototypes made with a similar process as this proposal could be safely used in actual surgery practices, while nylon performed poorly because of its hygroscopic properties.

Effects of Steam Heat and Dry Heat Sterilization Processes on 3D Printed Commercial Polymers Printed by Fused Deposition Modeling

“…Therefore, PLA’s low resistance to sterilization processes is expected to limit its wide use in single-use surgical devices. Frizziero et al (2021) studied 3D printed parts based on PLA subjected to a regular heat-sterilization cycle and they observed that 3D-PLA-based parts mainly maintained the geometry after a moist heat (MH) sterilization process conducted in an autoclave [ 21 ]. However, although PLA can maintain its geometry after the sterilization process, the mechanical resistance of such surgical devices is of fundamental importance and should be extensively studied.…”

Investigations on Factors Affecting 3D-Printed Holes Dimensional Accuracy and Repeatability

“…The significance level was 0.05. Many studies addressed the accuracy of 3D-printed surgical guide made of different materials and subjected to sterilization [26][27][28][29]. The rationale of these studies relates to the practical observations that some sterilization techniques can determine deformations of the surgical guides with critical impact on accuracy and the functionality of the device [13].…”

Can Steam Sterilization Affect the Accuracy of Point-of-Care 3D Printed Polyetheretherketone (PEEK) Customized Cranial Implants? An Investigative Analysis

“…The glass transition temperature (Tg) of polymers predicts how heat-induced sterilization causes chemical and structural changes in polymer properties [ 39 ]. A material with Tg close to steam-sterilization temperature can affect the polymeric chain mobility and its dimensional and mechanical characteristics [ 40 ].…”