Department of Orthopaedics, Balgrist University Hospital, 8008 Zurich, Switzerland; Institute for Biomechanics, ETH Zurich, 8093 Zurich, Switzerland.
Department of Orthopaedics, Balgrist University Hospital, 8008 Zurich, Switzerland.
J Biomech. 2021 Aug 26;125:110577. doi: 10.1016/j.jbiomech.2021.110577. Epub 2021 Jun 16.
3D printed clamps provide multiple advantages compared to potting for the fixation of spinal specimens and in a recent study, superior fixation stability was reported. The aim of this study was to evaluate the fixation efficacy of 3D printed vertebra clamps during routine application and to present and evaluate a novel clamp for sacrum fixation. Further, public access to the template files is provided. 98 human single-level cadaveric specimens were biomechanically tested in flexion-extension (FE), lateral bending (LB), axial rotation (AR), anteroposterior shear (AS), lateral shear (LS) and axial compression-decompression (AC). Loading amplitudes were +/-7.5 Nm for FE, LB and AR, +/- 150 N for AS and LS and + 400/-100 N for AC. The novel sacrum clamp was used in 8 specimens. The median relative motion between clamps and specimens was 0.6° in FE, 0.7° in LB, 0.3° in AR, 0.5 mm in AS, 0.5 mm in LS and 0.1 mm in AC. With sacrum clamps, the median relative motion was 0.3° in FE, 0.1° in LB, 0.08° in AR, 0.8 mm in AS, 0.7 mm in LS and 0.2 mm in AC. The vertebra clamps used during routine testing provided better stability compared to the values in the literature in all six loading directions (p < 0.05). The sacrum clamp showed superior anchoring stability in three loading directions compared to the caudal vertebra clamps (p < 0.05), while inferior stability was measured in AS (p < 0.001). We conclude that 3D printed vertebra clamps and 3D printed sacrum clamps represent reliable methods for specimen fixation during routine biomechanical testing.
3D 打印夹具与灌注相比，为脊柱标本的固定提供了多种优势，并且在最近的一项研究中，报告了更高的固定稳定性。本研究的目的是评估 3D 打印椎夹具在常规应用中的固定效果，并提出并评估一种用于骶骨固定的新型夹具。此外，还提供了模板文件的公共访问权限。98 个人体单节段尸体标本在屈伸（FE）、侧屈（LB）、轴向旋转（AR）、前后剪切（AS）、侧向剪切（LS）和轴向压缩-减压（AC）下进行生物力学测试。FE、LB 和 AR 的加载幅度为 +/-7.5 Nm，AS 和 LS 为 +/-150 N，AC 为+400/-100 N。新型骶骨夹具在 8 个标本中使用。FE 中夹具与标本之间的平均相对运动为 0.6°，LB 为 0.7°，AR 为 0.3°，AS 为 0.5 毫米，LS 为 0.5 毫米，AC 为 0.1 毫米。使用骶骨夹具时，FE 中的平均相对运动为 0.3°，LB 为 0.1°，AR 为 0.08°，AS 为 0.8 毫米，LS 为 0.7 毫米，AC 为 0.2 毫米。在所有六个加载方向上，常规测试中使用的椎夹具比文献中的值提供了更好的稳定性（p < 0.05）。与尾骨夹具相比，骶骨夹具在三个加载方向上具有更好的锚固稳定性（p < 0.05），而在 AS 中则测量到较差的稳定性（p < 0.001）。我们得出结论，3D 打印椎夹具和 3D 打印骶骨夹具是常规生物力学测试中标本固定的可靠方法。
