Abstract：
BACKGROUND: This study experimentally validated a computationally optimized screw number and screw distribution far cortical locking distal femur fracture plate and compared the results to traditional implants.
METHODS: 24 artificial femurs were osteotomized with a 10 mm fracture gap 60 mm proximal to the intercondylar notch. Three fixation constructs were used. (i) Standard locking plates secured with three far cortical locking screws inserted according to a previously optimized distribution in the femur shaft (n = 8). (ii) Standard locking plates secured with four standard locking screws inserted in alternating plate holes in the femur shaft (n = 8). (iii) Retrograde intramedullary nail secured proximally with one anterior-posterior screw and distally with two oblique screws (n = 8). Axial hip forces (700 and 2800 N) were applied while measuring axial interfragmentary motion, shear interfragmentary motion, and overall stiffness.
RESULTS: Experimental far cortical locking plate results compared well to published computational findings. Far cortical locking femurs contained the highest axial motion within the potential ideal range of 0.2-1 mm and a sheer-to-axial motion ratio < 1.6 at toe-touch weight-bearing (700 N). At full weight-bearing (2800 N), Standard locking-plated femurs had the only axial motion within 0.2-1 mm but had an excess shear-to-axial motion ratio. Nail-implanted femurs underperformed at both forces.
CONCLUSIONS: For toe-touch weight-bearing, the far cortical locking construct provided optimal biomechanics to allow moderate motion, which has been suggested to encourage early callus formation. Conversely, at full weight-bearing, the standard locking construct offered the biomechanical advantage on fracture motion.
METHODS: 24 artificial femurs were osteotomized with a 10 mm fracture gap 60 mm proximal to the intercondylar notch. Three fixation constructs were used. (i) Standard locking plates secured with three far cortical locking screws inserted according to a previously optimized distribution in the femur shaft (n = 8). (ii) Standard locking plates secured with four standard locking screws inserted in alternating plate holes in the femur shaft (n = 8). (iii) Retrograde intramedullary nail secured proximally with one anterior-posterior screw and distally with two oblique screws (n = 8). Axial hip forces (700 and 2800 N) were applied while measuring axial interfragmentary motion, shear interfragmentary motion, and overall stiffness.
RESULTS: Experimental far cortical locking plate results compared well to published computational findings. Far cortical locking femurs contained the highest axial motion within the potential ideal range of 0.2-1 mm and a sheer-to-axial motion ratio < 1.6 at toe-touch weight-bearing (700 N). At full weight-bearing (2800 N), Standard locking-plated femurs had the only axial motion within 0.2-1 mm but had an excess shear-to-axial motion ratio. Nail-implanted femurs underperformed at both forces.
CONCLUSIONS: For toe-touch weight-bearing, the far cortical locking construct provided optimal biomechanics to allow moderate motion, which has been suggested to encourage early callus formation. Conversely, at full weight-bearing, the standard locking construct offered the biomechanical advantage on fracture motion.
摘要：
背景：这项研究通过实验验证了计算优化的螺钉数量和螺钉分布远皮质锁定股骨远端骨折钢板，并将结果与传统植入物进行了比较。
方法：24个人工股骨在髁间切迹近60mm处截骨术，骨折间隙为10mm。使用了三种固定结构。(i)根据先前在股骨轴中优化的分布,用插入的三个远皮质锁定螺钉固定的标准锁定板(n=8)。(ii)用插入股骨轴中交替的板孔中的四个标准锁定螺钉固定的标准锁定板(n=8)。(iii)逆行髓内钉近端用一个前后螺钉固定,远端用两个斜螺钉固定(n=8)。在测量轴向碎片间运动时施加轴向髋力（700和2800N），剪切碎片间运动，和整体刚度。
结果：实验远皮质锁定钢板结果与已发表的计算结果比较好。远皮质锁定股骨在0.2-1mm的潜在理想范围内具有最高的轴向运动，并且在脚趾接触负重（700N）时，绝对轴向运动比<1.6。在完全承重(2800牛)时，标准的锁定钢板股骨仅在0.2-1毫米内具有轴向运动，但剪切与轴向运动的比率过大。钉植入股骨在两种力下均表现不佳。
结论：对于脚趾接触负重，远皮质锁定结构提供了最佳的生物力学，以允许适度的运动，这已被建议鼓励早期愈伤组织的形成。相反，在完全承重的情况下，标准锁定结构在骨折运动方面提供了生物力学优势。
方法：24个人工股骨在髁间切迹近60mm处截骨术，骨折间隙为10mm。使用了三种固定结构。(i)根据先前在股骨轴中优化的分布,用插入的三个远皮质锁定螺钉固定的标准锁定板(n=8)。(ii)用插入股骨轴中交替的板孔中的四个标准锁定螺钉固定的标准锁定板(n=8)。(iii)逆行髓内钉近端用一个前后螺钉固定,远端用两个斜螺钉固定(n=8)。在测量轴向碎片间运动时施加轴向髋力（700和2800N），剪切碎片间运动，和整体刚度。
结果：实验远皮质锁定钢板结果与已发表的计算结果比较好。远皮质锁定股骨在0.2-1mm的潜在理想范围内具有最高的轴向运动，并且在脚趾接触负重（700N）时，绝对轴向运动比<1.6。在完全承重(2800牛)时，标准的锁定钢板股骨仅在0.2-1毫米内具有轴向运动，但剪切与轴向运动的比率过大。钉植入股骨在两种力下均表现不佳。
结论：对于脚趾接触负重，远皮质锁定结构提供了最佳的生物力学，以允许适度的运动，这已被建议鼓励早期愈伤组织的形成。相反，在完全承重的情况下，标准锁定结构在骨折运动方面提供了生物力学优势。
