Tinga Selena, Tuyn David D, Kopp Rosalind J, Kim Stanley E
Comparative Orthopaedics and Biomechanics Laboratory, College of Veterinary Medicine, University of Florida, Gainesville, FL, United States.
Department of Mechanical and Aerospace Engineering, University of Florida, Gainesville, FL, United States.
Front Bioeng Biotechnol. 2023 Mar 8;11:999271. doi: 10.3389/fbioe.2023.999271. eCollection 2023.
Compare biomechanical properties of femurs implanted with either BioMedtrix biological fixation with interlocking lateral bolt (BFX+lb) or cemented (CFX) stems when subjected to 4-point bending or axial torsional forces. Twelve pairs of normal medium to large cadaveric canine femora were implanted with a BFX + lb ( = 12) and a CFX ( = 12) stem-one in the right and one in the left femora of the pair. Pre- and post-operative radiographs were made. Femora were tested to failure in either 4-point bending ( = 6 pairs) or axial torsion ( = 6 pairs), and stiffness, load or torque at failure, linear or angular displacement, and fracture configuration were noted. Implant position was acceptable in all included femora, but CFX stems were placed in less anteversion than BFX + lb stems in the 4-point bending group (median (range) 5.8 (-1.9-16.3) vs. 15.9 (8.4-27.9) anteversion, respectively ( = 0.04)). CFX implanted femora were more stiff than BFX + lb implanted femora in axial torsion (median (range) 2,387 (1,659-3,068) vs. 1,192 (795-2,150) N*mm/, respectively ( = 0.03)). One of each stem type, from different pairs, did not fail in axial torsion. There was no difference in stiffness or load to failure in 4-point bending, or in fracture configuration for either test, between implant groups. Increased stiffness of CFX implanted femurs under axial torsional forces may not be clinically relevant as both groups withstood expected forces. Based on this acute post-operative model using isolated forces, BFX + lb stems may be a suitable replacement for CFX stems in femurs with normal morphology (stovepipe and champagne flute morphology were not tested).
比较植入BioMedtrix带锁定侧螺栓生物固定（BFX+lb）或骨水泥固定（CFX）柄的股骨在承受四点弯曲或轴向扭转力时的生物力学特性。将十二对正常的中大型犬尸体股骨，一对中的右侧股骨植入BFX + lb柄（n = 12），左侧股骨植入CFX柄（n = 12）。拍摄术前和术后的X线片。将股骨进行四点弯曲（n = 6对）或轴向扭转（n = 6对）测试直至失效，并记录失效时的刚度、载荷或扭矩、线性或角位移以及骨折形态。所有纳入的股骨中植入物位置均可接受，但在四点弯曲组中，CFX柄的前倾角小于BFX + lb柄（前倾角中位数（范围）分别为5.8°（-1.9°-16.3°）和15.9°（8.4°-27.9°），P = 0.04）。在轴向扭转时，植入CFX的股骨比植入BFX + lb的股骨更硬（中位数（范围）分别为2387（1659-3068）N·mm/°和1192（795-2150）N·mm/°，P = 0.03）。每种柄型各有一根来自不同对的股骨在轴向扭转时未失效。植入物组之间在四点弯曲时的刚度或失效载荷以及两种测试的骨折形态方面均无差异。在轴向扭转力作用下，植入CFX的股骨刚度增加可能在临床上并无关联，因为两组都能承受预期的力。基于这个使用单一力的急性术后模型，对于形态正常的股骨（未测试烟囱形和香槟杯形形态），BFX + lb柄可能是CFX柄的合适替代品。
