Background:Elbow ulnar collateral ligament (UCL) repair with suture brace augmentation shows good time-zero biomechanical strength and a more rapid return to play compared with UCL reconstruction. However, there are concerns about overconstraint or stress shielding with nonabsorbable suture tape. Recently, a collagen-based bioinductive absorbable structural scaffold has been approved by the Food and Drug Administration for augmentation of soft tissue repair.Purpose/Hypothesis:This study aimed to assess the initial biomechanical performance of UCL repair augmented with this scaffold. We hypothesized that adding the bioinductive absorbable structural scaffold to primary UCL repair would impart additional time-zero restraint to the valgus opening.Study Design:Controlled laboratory study.Methods:Eight cadaveric elbow specimens—from midforearm to midhumerus—were utilized. In the native state, elbows underwent valgus stress testing at 30o, 60o, and 90o of flexion, with a cyclical valgus rotational torque. Changes in valgus rotation from 2- to 5-N·m torque were recorded as valgus gapping. Testing was then performed in 4 states: (1) native intact UCL—with dissection through skin, fascia, and muscle down to an intact UCL complex; (2) UCL-transected—distal transection of the ligament off the sublime tubercle; (3) augmented repair with bioinductive absorbable scaffold; and (4) repair alone without scaffold. The order of testing of repair states was alternated to account for possible plastic deformation during testing.Results:The UCL-transected state showed the greatest increase in valgus gapping of all states at all flexion angles. Repair alone showed similar valgus gapping to that of the UCL-transected state at 30° ( P = .62) and 60° of flexion ( P = .11). Bioinductive absorbable scaffold–augmented repair showed less valgus gapping compared with repair alone at all flexion angles ( P = .021, P = .024, and P = .024 at 30°, 60°, and 90°, respectively). Scaffold-augmented repair showed greater gapping compared with the native state at 30° ( P = .021) and 90° ( P = .039) but not at 60° of flexion ( P = .059). There was no difference when testing augmented repair or repair alone first.Conclusion:UCL repair augmented with a bioinductive, biocomposite absorbable structural scaffold imparts additional biomechanical strength to UCL repair alone, without overconstraint beyond the native state. Further comparative studies are warranted.Clinical Relevance:As augmented primary UCL repair becomes more commonly performed, use of an absorbable bioinductive scaffold may allow for improved time-zero mechanical strength, and thus more rapid rehabilitation, while avoiding long-term overconstraint or stress shielding.

中文翻译：

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使用结构生物感应支架增强尺侧副韧带修复：生物力学研究

背景：与 UCL 重建相比，采用缝合支架增强的肘部尺侧副韧带 (UCL) 修复显示出良好的零时生物力学强度，并且恢复比赛速度更快。然而，人们担心不可吸收缝合带会产生过度约束或应力屏蔽。最近，一种基于胶原蛋白的生物诱导可吸收结构支架已被美国食品和药物管理局批准用于增强软组织修复。目的/假设：本研究旨在评估用该支架增强 UCL 修复的初始生物力学性能。我们假设在初次 UCL 修复中添加生物感应可吸收结构支架将为外翻开口提供额外的零时约束。研究设计：受控实验室研究。方法：使用八个尸体肘部标本（从前臂中部到肱骨中部）。在自然状态下，肘部在 30 ℃时进行外翻压力测试哦, 60哦，和 90哦屈曲，具有周期性外翻旋转扭矩。外翻旋转从 2-N·m 扭矩到 5-N·m 扭矩的变化被记录为外翻间隙。然后在 4 种状态下进行测试：（1）天然完整的 UCL——通过皮肤、筋膜和肌肉解剖直至完整的 UCL 复合体； (2) UCL横断——从崇高结节处将韧带远端横断； (3)生物诱导可吸收支架增强修复； (4)单独修复，无需脚手架。交替修复状态的测试顺序，以考虑测试过程中可能出现的塑性变形。结果：UCL 横切状态显示所有屈曲角度下所有状态的外翻间隙增加最大。单独修复在 30° ( P = .62) 和 60° 屈曲 ( P = .11) 时显示出与 UCL 横断状态相似的外翻间隙。与单独修复相比，生物感应可吸收支架增强修复在所有屈曲角度下显示出更少的外翻间隙（分别在 30°、60° 和 90° 时 P = .021、P = .024 和 P = .024）。与原始状态相比，支架增强修复在 30° (P = .021) 和 90° (P = .039) 时显示出更大的间隙，但在 60° 屈曲时则没有 (P = .059)。首先测试增强修复或单独修复时没有差异。结论：用生物诱导、生物复合可吸收结构支架增强的 UCL 修复为单独的 UCL 修复提供了额外的生物力学强度，而没有超出天然状态的过度约束。需要进一步的比较研究。 临床相关性：随着增强的初级 UCL 修复变得越来越普遍，使用可吸收的生物感应支架可能会提高零时机械强度，从而更快地康复，同时避免长期过度约束或应力屏蔽。