Gould Heath P, Delaney Nicholas R, Parks Brent G, Melvani Roshan T, Hinton Richard Y
Department of Orthopaedic Surgery, MedStar Union Memorial Hospital, Baltimore, Maryland, USA.
Orthop J Sports Med. 2021 Mar 8;9(3):2325967121989282. doi: 10.1177/2325967121989282. eCollection 2021 Mar.
Femoral-sided graft fixation in medial patellofemoral ligament (MPFL) reconstruction is commonly performed using an interference screw (IS). However, the IS method is associated with several clinical disadvantages that may be ameliorated by the use of suture anchors (SAs) for femoral fixation.
To compare the load to failure and stiffness of SAs versus an IS for the femoral fixation of a semitendinosus autograft in MPFL reconstruction.
Controlled laboratory study.
Based on a priori power analysis, a total of 6 matched pairs of cadaveric knees were included. Specimens in each pair were randomly assigned to receive either SA or IS fixation. After an appropriate reconstruction procedure, the looped end of the MPFL graft was pulled laterally at a rate of 6 mm/s until construct failure. The best-fit slope of the load-displacement curve was then used to calculate the stiffness (N/mm) in a post hoc fashion. A paired test was used to compare the mean load to failure and the mean stiffness between groups.
No significant difference in load to failure was observed between the IS and the SA fixation groups (294.0 ± 61.1 vs 250.0 ± 55.9; = .352), although the mean stiffness was significantly higher in IS specimens (34.5 ± 9.6 vs 14.7 ± 1.2; = .004). All IS reconstructions failed by graft pullout from the femoral tunnel, whereas 5 of the 6 SA reconstructions failed by anchor pullout.
In this biomechanical study using a cadaveric model of MPFL reconstruction, SA femoral fixation was not significantly different from IS fixation in terms of load to failure. The mean load-to-failure values for both reconstruction techniques were greater than the literature-reported values for the native MPFL.
These results suggest that SAs are a biomechanically viable alternative for femoral-sided graft fixation in MPFL reconstruction.
在髌股内侧韧带（MPFL）重建术中，股骨侧移植物固定通常使用挤压螺钉（IS）。然而，IS方法存在一些临床缺点，使用缝线锚钉（SAs）进行股骨固定可能会改善这些缺点。
比较SAs和IS在MPFL重建术中对股薄肌自体移植物进行股骨固定时的失效载荷和刚度。
对照实验室研究。
基于预先的功效分析，共纳入6对匹配的尸体膝关节。每对标本随机分配接受SA或IS固定。经过适当的重建程序后，以6mm/s的速度将MPFL移植物的环形端向外拉，直至结构失效。然后，使用载荷-位移曲线的最佳拟合斜率以事后检验的方式计算刚度（N/mm）。采用配对t检验比较两组之间的平均失效载荷和平均刚度。
IS固定组和SA固定组之间在失效载荷方面未观察到显著差异（294.0±61.1对250.0±55.9；P = 0.352），尽管IS标本的平均刚度显著更高（34.5±9.6对14.7±1.2；P = 0.004）。所有IS重建均因移植物从股骨隧道中拔出而失败，而6例SA重建中有5例因锚钉拔出而失败。
在这项使用MPFL重建尸体模型的生物力学研究中，SA股骨固定在失效载荷方面与IS固定无显著差异。两种重建技术的平均失效载荷值均高于文献报道的天然MPFL的值。
这些结果表明，SAs是MPFL重建术中股骨侧移植物固定的一种生物力学上可行的替代方法。
