Department of Trauma, Hand and Reconstructive Surgery, Wilhelms University Muenster, Münster, Germany.
Arch Orthop Trauma Surg. 2011 Aug;131(8):1067-72. doi: 10.1007/s00402-011-1276-7. Epub 2011 Feb 18.
In ACL reconstruction using a soft tissue graft, aperture fixation with interference screws (IFS) can lacerate and rotate the graft and cause primary tunnel widening. To overcome these downsides, a new wedge-shaped implant (MegaShim, Karl Storz, Germany) was developed. We hypothesized that aperture fixation of hamstring ACL reconstruction using the MegaShim technique shows comparable structural properties when compared to interference screw fixation.
In a porcine knee model, ACL reconstructions with a tunnel diameter of 6, 7, 8 and 9 mm were performed and human hamstring grafts were fixed using the MegaShim technique (group I). In group 2, grafts were fixed in a hybrid fixation using a MegaShim and cortical flip button (FlippTack, Karl Storz, Germany). Interference screw graft fixation served as a control group (group III). Maximum load, yield load and stiffness were recorded using material testing machine. Grafts were cyclically preconditioned between 0 and 20 N for 10 cycles before the graft-bone complex was loaded to failure. Statistical evaluation was performed using SPSS Version 11.0.
Mean maximum load to failure for the hybrid fixation was significantly higher than after interference screw or MegaShim fixation. The difference between MegaShim and interference screw fixation showed no significant difference for 6 and 7 mm sizes. An 8 and 9 mm MegaShim fixation resulted in significantly lower ultimate failure load compared to interference screw fixation. Stiffness of grafts fixed using 6 mm MegaShim was significantly lower than grafts fixed with hybrid or interference screw fixation, whereas no significant differences were found in the 7, 8, and 9 mm fixations.
Aperture fixation using the MegaShim technique provides comparable structural properties compared to interference screw fixation. Hybrid fixation using MegaShim and cortical flip button results in significantly higher ultimate failure loads than both aperture fixation approaches. Smaller grafts (6 mm) showed significantly lower ultimate failure load and stiffness than interference screw fixation. The "MegaShim technique" is an alternative to interference screw fixation concerning initial fixation strength.
在使用软组织移植物进行 ACL 重建时，使用干扰螺钉（IFS）进行开口固定会撕裂和旋转移植物，并导致初始隧道变宽。为了克服这些缺点，开发了一种新型楔形植入物（MegaShim，Karl Storz，德国）。我们假设使用 MegaShim 技术进行的 ACL 重建的开口固定与干扰螺钉固定相比具有相当的结构性能。
在猪膝关节模型中，进行了直径为 6、7、8 和 9 毫米的 ACL 重建，并使用 MegaShim 技术（第 I 组）固定了人腘绳肌移植物。在第 2 组中，使用 MegaShim 和皮质翻转按钮（FlippTack，Karl Storz，德国）进行混合固定。干扰螺钉固定作为对照组（第 3 组）。使用材料试验机记录最大负载、屈服负载和刚度。在将移植物-骨复合物加载至失效之前，对移植物进行 0 至 20 N 的循环预条件处理 10 个周期。使用 SPSS 版本 11.0 进行统计评估。
混合固定的平均最大失效负载明显高于干扰螺钉或 MegaShim 固定后的负载。6 和 7 毫米尺寸的 MegaShim 和干扰螺钉固定之间的差异没有统计学意义。8 和 9 毫米 MegaShim 固定的最终失效负载明显低于干扰螺钉固定。使用 6 毫米 MegaShim 固定的移植物的刚度明显低于使用混合或干扰螺钉固定的移植物，而在 7、8 和 9 毫米固定中没有发现显著差异。
使用 MegaShim 技术进行开口固定可提供与干扰螺钉固定相当的结构性能。使用 MegaShim 和皮质翻转按钮的混合固定可导致最终失效负载明显高于两种开口固定方法。较小的移植物（6 毫米）的最终失效负载和刚度明显低于干扰螺钉固定。与干扰螺钉固定相比，“MegaShim 技术”是初始固定强度的替代方法。
