Rubel I F, Seligson D, Lai J L, Voor M J, Wang M
University of Louisville Hospital, Louisville, Kentucky 40292, USA.
J Orthop Trauma. 2001 Aug;15(6):429-32. doi: 10.1097/00005131-200108000-00008.
To determine the relative amount of fixation of self-reinforced poly-L-lactide (SR-PLLA) rods and Kirschner wires in bovine cancellous bone by comparing their pullout strength
An in vitro laboratory study was performed using bovine femurs. Ten two-millimeter-diameter pins of each type were inserted into cancellous bone and then pulled out, using a material testing machine. The maximum force (pullout strength) was selected over other measurements to compare the amount of fixation of the two types of pins. All of the pins were retrieved for microscopic analysis. A paired t test was performed to analyze the differences between the pullout strength of the two types of pins.
Orthopaedic Bioengineering Laboratory, University of Louisville School of Medicine, Louisville, Kentucky, U.S.A.
Two young fresh bovine distal femurs, ten two-millimeter-diameter Kirschner wires, ten two-millimeter-diameter bioabsorbable SR-PLLA rods
Pullout strength in Newtons, and microscopic pin surface aspect after insertion.
Significant differences were noted between the maximum force required to remove the two types of pins (p < 0.01) The K-wire mean pullout force was 37.7 N (SD 13.6), and the SR-PLLA rod mean pullout force was 53.6 N (SD 19.3). Microscopic analysis indicated surface modification only on the SR PLLA rods.
SR-PLLA composites have shown comparable clinical results to their metallic counterparts. In this study, the pullout strength of SR-PLLA rods was compared with that of conventional K-wires. A significant difference (p < 0.01) favoring bioabsorbable pullout strength was noted. The bioabsorbable pin surface modification during insertion is an interesting finding that warrants further investigation as a potential source of improved fixation.
SR-PLLA rods retain their hold in bovine cancellous bone better than K-wires. This finding offers to the orthopaedic surgeon more information about new pin fixation methods.
通过比较自增强聚-L-丙交酯（SR-PLLA）棒和克氏针在牛松质骨中的拔出强度，确定其相对固定量
使用牛股骨进行体外实验室研究。将每种类型的10根直径2毫米的销钉插入松质骨，然后使用材料试验机将其拔出。选择最大力（拔出强度）与其他测量值进行比较，以比较两种销钉的固定量。所有销钉均取出进行显微镜分析。进行配对t检验以分析两种销钉拔出强度之间的差异。
美国肯塔基州路易斯维尔市路易斯维尔大学医学院骨科生物工程实验室
两根年轻新鲜的牛远端股骨、10根直径2毫米的克氏针、10根直径2毫米的可生物吸收SR-PLLA棒
以牛顿为单位的拔出强度，以及插入后销钉表面微观情况
两种销钉拔出所需的最大力之间存在显著差异（p < 0.01）。克氏针平均拔出力为37.7 N（标准差13.6），SR-PLLA棒平均拔出力为53.6 N（标准差19.3）。显微镜分析表明仅SR-PLLA棒表面有改性。
SR-PLLA复合材料已显示出与金属同类材料相当临床效果。在本研究中，将SR-PLLA棒的拔出强度与传统克氏针的拔出强度进行了比较。发现有利于可生物吸收拔出强度的显著差异（p < 0.01）。插入过程中可生物吸收销钉的表面改性是一个有趣的发现，作为固定改善的潜在来源值得进一步研究。
SR-PLLA棒在牛松质骨中的固定比克氏针更好。这一发现为骨科医生提供了更多关于新型销钉固定方法的信息。
