Faculty of Medicine and University Hospital Cologne, Department of Orthopedics and Trauma Surgery, University of Cologne, Kerpener Str. 62, 50937 Cologne, Germany.
Department of Trauma and Reconstructive Surgery, University Hospital RWTH Aachen, Pauwelsstraße 30, 52074 Aachen, Germany.
Clin Biomech (Bristol). 2020 Dec;80:105153. doi: 10.1016/j.clinbiomech.2020.105153. Epub 2020 Aug 15.
Aim of this biomechanical investigation was to compare the biomechanical effects of a carbon fiber reinforced PEEK and titanium pedicle screw/rod device in osteoporotic human cadaveric spine.
Ten human fresh-frozen cadaveric lumbar spines (L1-L5) have been used and were randomized into two groups according to the bone mineral density. A monosegmental posterior instrumentation (L3-L4) using titanium pedicle screws and rods was carried out in group A and using carbon fiber reinforced PEEK in group B. A cyclic loading test was performed at a frequency of 3 Hz, starting with a peak of 500 N for the first 2000 cycles, up to 950 N for 100,000 cycles under a general preload with 100 N. All specimens were evaluated with regard to a potential collapse of the implanted pedicle screws. A CT supported digital measurement of cavities around the pedicle at 3 defined measuring points was performed. Finally, the maximum zero-time failure load of all specimens was determined using a universal testing machine (80% F).
Regarding maximum axial force (group A: 2835 N, group B: 3006 N, p = 0.595) and maximum compression (group A: 11.67 mm, group B: 15.15 mm, p = 0.174) no statistical difference could be shown between the two groups. However, significant smaller cavity formation around the pedicle screws could be observed in group B (p = 0.007), especially around the screw tip (p < 0.001).
Carbon fiber reinforced PEEK devices seem to be advantageous in terms of microscopic screw loosening compared to titanium devices.
本生物力学研究旨在比较碳纤维增强型聚醚醚酮（PEEK）和钛制椎弓根螺钉/棒装置在骨质疏松的人体尸体脊柱中的生物力学效果。
使用了 10 个人体新鲜冷冻的腰椎（L1-L5）标本，并根据骨密度将其随机分为两组。在组 A 中，使用钛制椎弓根螺钉和棒进行单节段后路器械固定（L3-L4），在组 B 中则使用碳纤维增强型 PEEK。在 3 Hz 的频率下进行循环加载测试，在前 2000 个循环中，峰值为 500 N，然后在 100 N 的总预载下，增加至 950 N，进行 10 万次循环。所有标本均评估了植入椎弓根螺钉潜在的塌陷情况。使用 CT 对 3 个定义的测量点处的椎弓根周围的空腔进行了数字测量。最后，使用万能试验机（80% F）确定所有标本的最大零时刻失效载荷。
在最大轴向力（组 A：2835 N，组 B：3006 N，p = 0.595）和最大压缩（组 A：11.67 mm，组 B：15.15 mm，p = 0.174）方面，两组之间没有统计学差异。然而，在组 B 中可以观察到椎弓根螺钉周围的空腔形成明显较小（p = 0.007），尤其是在螺钉尖端周围（p < 0.001）。
与钛制器械相比，碳纤维增强型 PEEK 装置在微观螺钉松动方面似乎具有优势。
