Hudson Caleb C, Lewis Daniel D, Cross Alan R, Dunbar Nicholas J, Horodyski MaryBeth, Banks Scott A, Pozzi Antonio
Comparative Orthopaedics and Biomechanics Laboratory, University of Florida, Gainesville, FL 32610, USA.
Vet Surg. 2012 Nov;41(8):954-65. doi: 10.1111/j.1532-950X.2012.01035.x. Epub 2012 Sep 7.
To evaluate the stiffness, displacement, ring deformation and bone model motion of 3 configuations of linear-circular hybrid fixator constructs loaded in axial compression, craniocaudal and mediolateral bending, and torsion.
Biomechanical evaluation.
Three hybrid construct configurations with 8 replicates/configuration.
Construct Ia used a single, 84 mm, incomplete ring and 2 tensioned olive wires to stabilize 1 bone segment and a primary hybrid rod with 3 fixation pins to stabilize the other bone segment. Constructs Ia(d) and Ib were similar to Ia with the addition of a secondary diagonal hybrid rod. Construct Ib had a fixation pin inserted orthogonally from the diagonal rod. Constructs were loaded for 10 cycles in each mode of loading using a materials testing machine. Ring deformation was assessed by obtaining serial ring measurements. Bone model motion at the fracture gap as a result of loading was also calculated.
Axial compression: constructs Ia(d) and Ib were significantly stiffer than construct Ia. Craniocaudal bending: Construct Ib was significantly stiffer than construct Ia. Mediolateral bending: there were no significant differences between constructs. Torsion: Construct Ib was significantly stiffer than constructs Ia and Ia(d) . Permanent ring deformation did not occur. Bone model translational motion decreased in constructs Ia(d) and Ib compared to construct Ia.
Addition of a secondary hybrid rod as well as biplanar fixation pin placement improved construct stiffness in several loading modes.
评估线性-环形混合固定器结构的三种构型在轴向压缩、颅尾向和内外侧弯曲以及扭转载荷下的刚度、位移、环变形和骨模型运动。
生物力学评估。
三种混合结构构型，每种构型8个重复样本。
构型Ia使用一个84毫米的单节段不完全环和2根张紧的橄榄形钢丝来稳定一个骨段，并用一根带有3个固定销的主混合杆来稳定另一个骨段。构型Ia(d)和Ib与Ia相似，但增加了一根次级对角混合杆。构型Ib从对角杆垂直插入一根固定销。使用材料试验机对结构在每种加载模式下加载10个循环。通过获取连续的环测量值来评估环变形。还计算了加载导致的骨折间隙处骨模型的运动。
轴向压缩：构型Ia(d)和Ib比构型Ia显著更硬。颅尾向弯曲：构型Ib比构型Ia显著更硬。内外侧弯曲：各构型之间无显著差异。扭转：构型Ib比构型Ia和Ia(d)显著更硬。未发生永久性环变形。与构型Ia相比，构型Ia(d)和Ib中的骨模型平移运动减少。
添加次级混合杆以及双平面固定销放置在几种加载模式下提高了结构刚度。
