Ellwein Alexander, Stryga Marvin, Ferle Manuel, Pastor Marc-Frederic, Lill Helmut, Smith Tomas
Department of Orthopaedic Surgery, Medical School Hannover, DIAKOVERE Annastift, Hannover, Germany; Department of Orthopaedic Surgery and Traumatology, DIAKOVERE Friederikenstift, Hannover, Germany.
Department of Orthopaedic Surgery, Medical School Hannover, DIAKOVERE Annastift, Hannover, Germany.
J Hand Surg Am. 2022 Oct;47(10):1016.e1-1016.e8. doi: 10.1016/j.jhsa.2021.08.004. Epub 2021 Sep 24.
Ligament bracing is a technique of suture reinforcement that can be used to augment lateral ulnar collateral ligament repair in the treatment of posterolateral rotatory instability of the elbow, thereby improving early stability of the repair. However, multiple failures of the ulnar anchor during implantation have been documented. We hypothesized that the use of a cortical button for ulnar fixation of the ligament brace would be biomechanically comparable to a suture anchor construct.
Sixteen elbows were tested with a materials testing machine. The intact, dissected, and repaired lateral collateral ligament complex was tested with a cyclic varus rotational torque of 0.5-3.5 Nm in 120°, 90°, 60°, and 30° elbow flexion. For the repair, the specimens were randomized into 2 groups: ulnar fixation of the ligament bracing using a suture anchor and ulnar fixation of the ligament bracing using a cortical button. The number of implant failures was documented. A load-to-failure protocol was conducted in 90° elbow flexion.
Load to failure was comparable and was found to be 20.7 Nm in the suture anchor group and 21.8 Nm in the cortical button group. Laxity after ligament bracing did not differ significantly between suture anchor and cortical button fixation. Compared with the native ligament, the laxity was significantly reduced after ligament bracing. The failure mode was slippage of the suture tape through the humeral anchor in all cases. Additionally, the capitellum was damaged in 9 of 16 cases.
A cortical button for ulnar fixation of the ligament bracing was comparable with a suture anchor fixation with regard to biomechanical properties such as laxity and load to failure.
A cortical button fixation is less prone to failure of insertion. This would improve the implantation technique, while clinical results are expected to be comparable.
韧带支撑是一种缝合增强技术，可用于在治疗肘关节后外侧旋转不稳定时加强尺侧副韧带修复，从而提高修复的早期稳定性。然而，已有文献记载尺侧锚钉在植入过程中多次失败。我们假设使用皮质纽扣进行韧带支撑的尺侧固定在生物力学上与缝合锚钉结构相当。
用材料试验机对16个肘关节进行测试。对完整、解剖和修复后的外侧副韧带复合体在肘关节屈曲120°、90°、60°和30°时施加0.5 - 3.5 Nm的周期性内翻旋转扭矩进行测试。对于修复，将标本随机分为两组：使用缝合锚钉进行韧带支撑的尺侧固定和使用皮质纽扣进行韧带支撑的尺侧固定。记录植入失败的次数。在肘关节屈曲90°时进行失效负荷试验。
失效负荷相当，缝合锚钉组为20.7 Nm，皮质纽扣组为21.8 Nm。缝合锚钉和皮质纽扣固定后韧带支撑后的松弛度无显著差异。与天然韧带相比，韧带支撑后松弛度显著降低。所有病例的失效模式均为缝合带从肱骨锚钉处滑脱。此外，16例中有9例出现了小头骨损伤。
在松弛度和失效负荷等生物力学特性方面，用于韧带支撑尺侧固定的皮质纽扣与缝合锚钉固定相当。
皮质纽扣固定不易出现植入失败。这将改进植入技术，同时预期临床结果相当。
