Sterility of 3D-Printed Orthopedic Implants Using Fused Deposition Modeling

Abstract

The use of 3-dimensional (3D) printing in orthopedics is developing rapidly and impacting the areas of preoperative planning, surgical guides, and simulation. As this technology continues to improve, the greatest impact of 3D printing may be in low- and middle-income countries where surgical items are in short supply. This study investigated sterility of 3D-printed ankle fracture fixation plates and cortical screws. The hypothesis was that the process of heated extrusion in fused deposition modeling printing would create sterile prints in a timely fashion that would not require postproduction sterilization. A free computer-assisted design program was used to design the implant models. One control group and 8 study groups were printed. Print construct, orientation, size, and postproduction sterilization differed among the groups. Sterility was assessed using thioglycollate broth cultures at 24 hours, 48 hours, and 7 days. Positive growth was speciated for aerobic and anaerobic bacteria. Print time and failed prints were recorded. Control samples were 100% positive for bacterial growth. All test samples remained sterile at all time points (100%). Speciation of control samples was obtained, and Staphylococcus was the most common species. Print times varied; however, no print time exceeded 6.75 minutes. Eighteen prints (17%) failed in the printing process. These findings demonstrate an intrinsic sterilization process associated with fused deposition modeling 3D printing and indicate the feasibility of 3D-printed surgical implants and equipment for orthopedic applications. With future research, 3D-printed implants may be a treatment modality to assist orthopedic surgeons in low- and middle-income countries. [ Orthopedics . 2020; 43(1): 46–51.]

Clinical Applications of Patient-Specific 3D Printed Models in Cardiovascular Disease: Current Status and Future Directions

“…Thus, it is important to have a clear understanding of the clinical value of 3D printing and potential limitations. The review article aims to provide an overview of 3D printed models in medical applications, specifically focusing its value in cardiovascular disease since its clinical applications in orthopaedics and maxillofacial areas are well explored and confirmed in the literature [23][24][25]. Further to the commonly reported usefulness of 3D printed models, use of 3D printed models for developing optimal computed tomography (CT) scanning parameters in cardiovascular disease is discussed and future research directions are highlighted.…”

Eficácia na esterilização de objetos produzidos pela impressão 3D com material ácido polilático: Comparação entre os métodos autoclave e óxido de etileno

“…Printing with partial internal filling (% infill ) is common in household printings because the process is faster and more economical by using less raw material. Neches et al 22 and Skelley et al 23 demonstrated efficient sterilization of PLA printed objects automatically by the high temperature generated for the melting of the material during the printing of the objects, including the interior of the parts (∼ 200°C), requiring no further processing. Aguardo-Maestro et al 24 compared autoclave, OE, and plasma gas methods in the sterilization of hollow printed objects after inoculating a bacteria suspension inside them, finding efficacy only in the first two methods.…”

“…A impressão com enchimento interno parcial (% de infill ) é comum nas impressões domiciliares pois o processo é mais rápido e econômico por utilizar menor quantidade de matéria-prima. Neches et al 22 , e Skelley et al 23 demonstraram esterilização eficiente dos objetos impressos em PLA automaticamente pela alta temperatura gerada para o derretimento do material durante a impressão dos objetos, incluindo o interior das peças (∼ 200°C), não necessitando de processamento complementar. Aguardo-Maestro et al 24 compararam os métodos autoclave, OE e gás plasma na esterilização dos objetos impressos de modo oco após inocular uma suspensão de bactérias no interior dos mesmos, constatando eficácia apenas nos dois primeiros.…”

How to Sterilize Polylactic Acid Based Medical Devices?

“…Other authors also studied 3D printing as a sterilization method but with ABS as a raw material [ 56 , 57 ]. Kondor and colleagues successfully manufactured a surgical instrument kit where 90% of the parts taken directly after printing were determined to be sterile by biological tests [ 56 ].…”

“…The sterility of 3D-printed ankle fracture fixation plates and cortical screws (using ABS) were therefore assessed using thioglycollate broth cultures at 24 h, 48 h, and 7 days. The sterility of 100% of all test samples and the bacterial growth in the positive control demonstrated an intrinsic sterilization process suitable for FDM 3D printing in future orthopaedic applications [ 57 ]. The “in vitro” environment of this study also limited the ability to generalize the results as being sterile and safe for long term orthopaedic implants.…”