Hurbanek Jason G, Anderson Kyle, Crabtree Stephanie, Karnes G Joshua
Henry Ford Hospital, Detroit, Michigan, USA.
Am J Sports Med. 2009 Mar;37(3):526-33. doi: 10.1177/0363546508326986. Epub 2009 Jan 23.
Surgical reconstruction of the ulnar collateral ligament has evolved since Frank Jobe's original description. The "docking technique" is a popular modification that allows for securing the graft within a single humeral tunnel. More recently, interference screw fixation has been introduced as a means of improving the ultimate strength, stiffness, and kinematics of these constructs.
This study was conducted to compare the biomechanical performance of the docking technique with and without interference screw fixation in the humerus.
Controlled laboratory study.
Nine matched pairs of human cadaveric elbows (age 49.9 +/- 8.0 years) were reconstructed with a tendon graft using the docking technique (group 1) or the docking technique with the addition of a 4.75-mm bioabsorbable humeral interference screw (group 2). Before the reconstruction, joint laxity was measured on each specimen with the ulnar collateral ligament intact and then after transection of the ligament. Laxity measurements were repeated after the reconstruction. Failure testing was then performed at 70 degrees of elbow flexion. The specimens were preloaded with a 1-N.m moment and then loaded to failure at a displacement rate of 14 mm/s to approximate 50% strain per second.
Within group 1, the elbow laxity of the reconstructed state was significantly greater than the intact state at all tested flexion angles (P < .021). Within group 2, no statistically significant difference existed in elbow laxity between the intact state and the reconstructed state. When comparing laxities between groups, group 1 tended to be more lax at all tested flexion angles but was only significantly greater at 105 degrees of flexion. The most common mode of failure for both groups involved the sutures pulling out of the tendon. No significant difference was found for ultimate moment of failure between the 2 groups. However, the moment associated with 3 mm of gap formation for group 2 (12.8 +/- 4.2 N x m) was statistically greater than that of group 1 (7.5 +/- 1.2 N x m) (P = .001). The stiffness of group 2 (14.7 +/- 6.4 N/mm) was significantly greater than group 1 (9.9 +/- 3.1 N/mm) (P = .044).
The biomechanical performance of the docking technique with and without a humeral interference screw is similar.
The stiffness of the construct, along with the difference in moment that allows a 3-mm gap formation, suggests that the addition of a humeral interference screw is potentially beneficial. Further research in a healing model will help clarify this benefit.
自弗兰克·乔布最初描述以来，尺侧副韧带的手术重建技术不断发展。“对接技术”是一种流行的改良方法，可将移植物固定在单一的肱骨隧道内。最近，采用干涉螺钉固定作为提高这些结构的极限强度、刚度和运动学性能的一种手段。
本研究旨在比较有和没有肱骨干涉螺钉固定的对接技术在生物力学性能方面的差异。
对照实验室研究。
使用腱移植物，采用对接技术（第1组）或对接技术并加用4.75毫米可吸收肱骨干涉螺钉（第2组），对9对匹配的人体尸体肘关节（年龄49.9±8.0岁）进行重建。重建前，在尺侧副韧带完整时测量每个标本的关节松弛度，然后在韧带横断后再次测量。重建后重复测量松弛度。然后在肘关节屈曲70度时进行失效测试。标本先施加1牛·米的力矩进行预加载，然后以14毫米/秒的位移速率加载至失效，以达到每秒约50%的应变。
在第1组中，在所有测试的屈曲角度下，重建状态的肘关节松弛度均显著大于完整状态（P <.021）。在第2组中，完整状态与重建状态之间的肘关节松弛度无统计学显著差异。比较两组之间的松弛度时，在所有测试的屈曲角度下，第1组往往更松弛，但仅在屈曲105度时显著更大。两组最常见的失效模式均为缝线从肌腱中拔出。两组之间的极限失效力矩无显著差异。然而，第2组（12.8±4.2牛·米）与形成3毫米间隙相关的力矩在统计学上大于第1组（7.5±1.2牛·米）（P =.001）。第2组的刚度（14.7±6.4牛/毫米）显著大于第1组（9.9±3.1牛/毫米）（P =.044）。
有和没有肱骨干涉螺钉的对接技术在生物力学性能方面相似。
该结构的刚度以及允许形成3毫米间隙的力矩差异表明，加用肱骨干涉螺钉可能有益。在愈合模型中的进一步研究将有助于阐明这种益处。
