Abstract：
BACKGROUND: 3D printing, which is becoming ever more widespread in orthopedic surgery, requires specific materials. Polylactic acid (PLA) is the most widely used in general-purpose 3D printing, but its thermosensitivity can be incompatible with sterilization. Even so, it is easy to use, inexpensive, non-toxic and biodegradable. Controversy surrounds its use. 3D printing of directly sterilizable PLA parts according to surgeons\' needs would be highly advantageous, but doubts remain. We therefore performed an in vitro study to determine which PLAs resist steam sterilization regarding deformation.
OBJECTIVE: The study hypothesis was that, depending on make and shape, 3D-printed PLA parts can retain their properties after steam sterilization.
METHODS: We selected 4 makes of PLA and used each to print 4 simple cubes and 4 complex shapes corresponding to cuboid bones. They were subjected to steam sterilization under normal French hospital conditions. The size of the cubes was measured before and after sterilization, using a digital caliper.
RESULTS: Cuboid parts in HT-PLA and PLA-WANAO showed mean deformation of -0.02mm and -0.4mm, respectively after sterilization, the differences being non-significant (p=0.679 and p=0.241, respectively). Cuboid parts in PLA-SUNLU and PLA-G3D showed significant mean deformation: respectively, -1.37mm (p=0.026) and -35.03mm (p>0.001). Cubes in all types of PLA showed significant mean deformation: HT-PLA, -0.61mm (p=0.004); PLA-SUNLU, -2.70mm (p=0.002); PLA-G3D, -28.64mm (p>0.001); and PLA-WANAO, -1.33mm (p=0.010).
CONCLUSIONS: The study confirmed recent findings that steam sterilization is feasible with certain PLA-printed parts, with deformations less than 1mm, and that choice of PLA is crucial for success. Computer-designed objects (here, cubes) did not resist sterilization without significant deformation. Analysis of resistance to various stresses was not performed, and therefore it cannot be claimed that the process could be used other than for printing anatomic parts. Use of 3D printing in French hospitals is probably a real source of innovation and improvement in care quality; however, a legal framework needs establishing for the use of 3D-printed parts, to ensure patient safety and promote research in this field.
METHODS: III; prospective in vitro study.
OBJECTIVE: The study hypothesis was that, depending on make and shape, 3D-printed PLA parts can retain their properties after steam sterilization.
METHODS: We selected 4 makes of PLA and used each to print 4 simple cubes and 4 complex shapes corresponding to cuboid bones. They were subjected to steam sterilization under normal French hospital conditions. The size of the cubes was measured before and after sterilization, using a digital caliper.
RESULTS: Cuboid parts in HT-PLA and PLA-WANAO showed mean deformation of -0.02mm and -0.4mm, respectively after sterilization, the differences being non-significant (p=0.679 and p=0.241, respectively). Cuboid parts in PLA-SUNLU and PLA-G3D showed significant mean deformation: respectively, -1.37mm (p=0.026) and -35.03mm (p>0.001). Cubes in all types of PLA showed significant mean deformation: HT-PLA, -0.61mm (p=0.004); PLA-SUNLU, -2.70mm (p=0.002); PLA-G3D, -28.64mm (p>0.001); and PLA-WANAO, -1.33mm (p=0.010).
CONCLUSIONS: The study confirmed recent findings that steam sterilization is feasible with certain PLA-printed parts, with deformations less than 1mm, and that choice of PLA is crucial for success. Computer-designed objects (here, cubes) did not resist sterilization without significant deformation. Analysis of resistance to various stresses was not performed, and therefore it cannot be claimed that the process could be used other than for printing anatomic parts. Use of 3D printing in French hospitals is probably a real source of innovation and improvement in care quality; however, a legal framework needs establishing for the use of 3D-printed parts, to ensure patient safety and promote research in this field.
METHODS: III; prospective in vitro study.
摘要：
背景：3D打印，这在骨科手术中变得越来越普遍，需要特定的材料。聚乳酸（PLA）是通用3D打印中使用最广泛的，但它的热敏感性可能与灭菌不相容。即便如此,它很容易使用，便宜,无毒和可生物降解。围绕其使用存在争议。根据外科医生的需要，3D打印可直接消毒的PLA零件将是非常有利的，但疑虑依然存在。因此，我们进行了一项体外研究，以确定哪些PLA在变形方面抵抗蒸汽灭菌。
目的：研究假设是，取决于品牌和形状，3D打印的PLA零件在蒸汽灭菌后可以保持其性能。
方法：我们选择了4种PLA制造，并分别打印了4种简单的立方体和4种对应于长方体骨骼的复杂形状。他们在正常的法国医院条件下接受蒸汽灭菌。在灭菌前后测量立方体的大小，使用数字卡尺。
结果：HT-PLA和PLA-WANAO中的长方体零件显示出-0.02mm和-0.4mm的平均变形，分别灭菌后，差异不显著(分别为p=0.679和p=0.241)。PLA-SUNLU和PLA-G3D中的长方体零件分别显示出显着的平均变形：-1.37mm（p=0.026）和-35.03mm（p>0.001）。所有类型的PLA中的立方体均显示出显着的平均变形：HTPLA，-0.61mm(p=0.004);PLA-SUNLU,-2.70mm(p=0.002);PLAG3D,-28.64mm（p>0.001）；和PLA-WANAO，-1.33mm（p=0.010）。
结论：这项研究证实了最近的发现，蒸汽灭菌对某些PLA打印部件是可行的，变形小于1毫米，解放军的选择对成功至关重要。计算机设计的对象(这里，立方体）不抵抗灭菌而没有明显变形。没有进行对各种应力的抵抗力分析，因此，不能声称该方法可以用于打印解剖部件。在法国医院使用3D打印可能是创新和改善护理质量的真正来源;然而，需要建立使用3D打印部件的法律框架，确保患者安全并促进该领域的研究。
方法：III；前瞻性体外研究。
目的：研究假设是，取决于品牌和形状，3D打印的PLA零件在蒸汽灭菌后可以保持其性能。
方法：我们选择了4种PLA制造，并分别打印了4种简单的立方体和4种对应于长方体骨骼的复杂形状。他们在正常的法国医院条件下接受蒸汽灭菌。在灭菌前后测量立方体的大小，使用数字卡尺。
结果：HT-PLA和PLA-WANAO中的长方体零件显示出-0.02mm和-0.4mm的平均变形，分别灭菌后，差异不显著(分别为p=0.679和p=0.241)。PLA-SUNLU和PLA-G3D中的长方体零件分别显示出显着的平均变形：-1.37mm（p=0.026）和-35.03mm（p>0.001）。所有类型的PLA中的立方体均显示出显着的平均变形：HTPLA，-0.61mm(p=0.004);PLA-SUNLU,-2.70mm(p=0.002);PLAG3D,-28.64mm（p>0.001）；和PLA-WANAO，-1.33mm（p=0.010）。
结论：这项研究证实了最近的发现，蒸汽灭菌对某些PLA打印部件是可行的，变形小于1毫米，解放军的选择对成功至关重要。计算机设计的对象(这里，立方体）不抵抗灭菌而没有明显变形。没有进行对各种应力的抵抗力分析，因此，不能声称该方法可以用于打印解剖部件。在法国医院使用3D打印可能是创新和改善护理质量的真正来源;然而，需要建立使用3D打印部件的法律框架，确保患者安全并促进该领域的研究。
方法：III；前瞻性体外研究。
