Lacheta Lucca, Miles Jon, Douglass Brenton, Millett Peter
Steadman Philippon Research Institute, Vail, Colorado, U.S.A.
Center for Musculoskeletal Surgery, Charitè Universitaetsmedizin Berlin, Berlin, Germany.
Arthrosc Sports Med Rehabil. 2021 Feb 25;3(2):e549-e554. doi: 10.1016/j.asmr.2020.12.008. eCollection 2021 Apr.
To investigate the biomechanical influence of differential loading of suture strands (torque) on the fixation strength of knotted and knotless all-suture anchors.
The biomechanical strength of 48 all-suture anchors was evaluated for 4 conditions in polyurethane foam blocks: (1) 12 knotted all-suture anchors loaded proportionately, (2) 12 knotted all-suture anchors with 1 suture strand bearing 50% of total force (partial torque), (3) 12 knotted all-suture anchors with 1 strand fixated and the other loaded (full torque), and (4) 12 knotless all-suture anchors with the loop kept open via a fixed rod. Force for 1 mm and 2 mm of displacement and ultimate failure load were assessed.
For 1 mm of displacement, groups 2, 3, and 4 showed significantly lower forces than group 1 (all < .001), with no statistically significant difference between groups 2 and 3 ( = .516); for 2 mm of displacement, all groups showed significantly lower forces than group 1 ( < .001), which positively correlated with applied torque. No differences in the mean ultimate loads observed between testing groups 1, 2, and 4 were noted, with 93.3 ± 3.8 N, 91.4 ± 4.7 N, and 92.6 ± 5.6 N, respectively; however, group 3 exhibited a significantly lower mean ultimate load (62.3 ± 1.7 N) than all other groups ( < .001).
The ultimate failure load of knotted and knotless all-suture anchor fixation was partially affected by loading differentials between strands in this validated foam block model. Differential loading of knotted all-suture anchor fixation presented greater initial displacement when compared with symmetrically loaded knotted all-suture anchors. Despite an initial increase in displacement, knotless all-suture anchors showed similar ultimate failure loads to knotted all-suture anchors with strands loaded equally.
The role of suture strand loading imbalance on anchor fixation is variable and should be considered during placement and fixation of the repair constructs in a clinical setting.
研究缝线股线的差异加载（扭矩）对打结和无结全缝线锚钉固定强度的生物力学影响。
在聚氨酯泡沫块中对48个全缝线锚钉在4种条件下的生物力学强度进行评估：（1）12个打结全缝线锚钉按比例加载；（2）12个打结全缝线锚钉，其中1根缝线股线承受总力的50%（部分扭矩）；（3）12个打结全缝线锚钉，1根股线固定而另一根加载（全扭矩）；（4）12个无结全缝线锚钉，通过固定杆使环保持打开状态。评估1毫米和2毫米位移时的力以及极限破坏载荷。
对于1毫米位移，第2、3和4组的力显著低于第1组（均P <.001），第2组和第3组之间无统计学显著差异（P =.516）；对于2毫米位移，所有组的力均显著低于第1组（P <.001），且与施加的扭矩呈正相关。第1、2和4测试组之间观察到的平均极限载荷无差异，分别为93.3±3.8牛、91.4±4.7牛和92.6±5.6牛；然而，第3组的平均极限载荷（62.3±1.7牛）显著低于所有其他组（P <.001）。
在这个经过验证的泡沫块模型中，打结和无结全缝线锚钉固定的极限破坏载荷部分受股线间加载差异的影响。与对称加载的打结全缝线锚钉相比，打结全缝线锚钉固定的差异加载呈现出更大的初始位移。尽管位移最初有所增加，但无结全缝线锚钉的极限破坏载荷与股线均匀加载的打结全缝线锚钉相似。
缝线股线加载不平衡对锚钉固定的作用是可变的，在临床环境中修复结构的放置和固定过程中应予以考虑。
