Department of Chemical and Biomedical Engineering, Cleveland State University, Cleveland, OH 44115, USA.
Department of Mechanical Engineering, Cleveland State University, Cleveland, OH 44115, USA.
Injury. 2021 Oct;52(10):2820-2826. doi: 10.1016/j.injury.2021.08.006. Epub 2021 Aug 8.
Bone staples are internal fixation devices that are frequently used in the foot, ankle, and hand to provide stabilization. Fixation stability is vital after fusion or fracture surgeries to ensure proper bone healing. Patients undergoing surgeries that require fixation to keep bones aligned and stable may present with diminishing bone mechanical properties, and this may compromise the ability of the fixation hardware to maintain a stable construct. The purpose of this study was to investigate the mechanical performance of shape memory and superelastic nitinol bone staples with different bridge geometries in normal, osteopenic, and osteoporotic bone models. Contact forces and maximum principal stress and strain in the bone were recorded.
Finite element simulations of a bone staple fixation procedure were performed to examine the initial and post-surgery contact force, as well as the maximum principal stress and strain of 15 mm bridge and 20 mm bridge staple-bone constructs.
Shape memory nitinol staples exhibited higher contact forces compared to superelastic nitinol staples. Nitinol bone staples with 20 mm bridge lengths displayed higher contact forces and lower stresses in all bone types, as well as lower strains in osteoporotic bone models compared to nitinol staples with a 15 mm bridge length.
Nitinol bone staple constructs with 20 mm bridge length staples provide higher contact forces and display lower stresses in the bone than 15 mm bridge staple-bone constructs, which may be beneficial in bone with diminishing mechanical properties. Both superelastic and shape memory effect nitinol staples provide adequate compression and stress relief. However, if osteopenia is present, shape memory effect nitinol staples with a 20 mm bridge length may provide more stress relief and compression, if the bone anatomy allows.
骨钉是一种常用于足部、踝关节和手部的内固定装置，用于提供稳定性。在融合或骨折手术后，固定稳定性至关重要，以确保骨骼愈合良好。接受需要固定以保持骨骼对齐和稳定的手术的患者可能会出现骨骼机械性能降低的情况，这可能会影响固定硬件维持稳定结构的能力。本研究旨在研究不同桥接几何形状的形状记忆和超弹性镍钛诺骨钉在正常、骨质疏松和骨质疏松症骨骼模型中的力学性能。记录了骨骼中的接触力以及最大主应力和应变。
对骨钉固定程序的有限元模拟进行了研究，以检查初始和手术后的接触力，以及 15mm 桥接和 20mm 桥接骨钉-骨结构的最大主应力和应变。
与超弹性镍钛诺骨钉相比，形状记忆镍钛诺骨钉表现出更高的接触力。在所有类型的骨骼中，20mm 桥长的镍钛诺骨钉具有更高的接触力和更低的应力，与 15mm 桥长的镍钛诺骨钉相比，在骨质疏松症骨骼模型中具有更低的应变。
与 15mm 桥接骨钉相比，20mm 桥长的镍钛诺骨钉具有更高的接触力和骨骼中的低应力，这可能对机械性能降低的骨骼有益。超弹性和形状记忆效应镍钛诺骨钉均可提供足够的压缩和缓解压力。然而，如果存在骨质疏松症，如果骨骼解剖允许，20mm 桥长的形状记忆效应镍钛诺骨钉可能会提供更多的压力缓解和压缩。
