Background: Anterior cruciate ligament (ACL) reconstruction (ACLR) in the presence of excessive posterior tibial slope (PTS) is a well-established risk factor for increased ACL graft forces and a heightened risk of graft failure. Purpose/Hypothesis: The primary aim of this study was to evaluate whether lateral extra-articular tenodesis (LET) could mitigate the adverse effects of increased PTS on knee kinematics and ACL graft forces, achieving results comparable to those of slope-reducing osteotomy (SRO). It was hypothesized that LET would provide similar improvements in knee stability and graft force reduction to SRO in the presence of increased PTS. A secondary aim was to determine if an ALC injury exacerbates the effect of increased PTS on ACL graft forces and overall knee stability. It was hypothesized that ALC injury would amplify the negative effects of increased PTS. Study Design: Controlled laboratory study. Methods: Eight fresh-frozen cadaveric specimens were prepared, excluding those with previous surgery or significant knee pathology. ACLR was performed using a quadrupled hamstring tendon autograft. The effects of LET and SRO were tested at various degrees of PTS (0°, 10°, and 20°). A simulated pivot-shift maneuver was used to measure ACL graft loads, anterior tibial translation (ATT), and internal rotation (IR). Mixed-effects models were utilized to analyze the data. Results: Increasing PTS resulted in significant increases in ACL graft forces ( P < .001), ATT ( P < .001), and IR ( P < .001). LET reduced ACL graft loads by 22.1% at 10° and 36.6% at 20° of PTS. In contrast, a 10° SRO showed only a 2.6% reduction at 10° and 23.9% at 20° of PTS. There were no significant differences in graft forces between the postosteotomy states and LET augmentation states at both 10° and 20° of tibial slope, suggesting equivalent efficacy in reducing graft loads. Additionally, LET significantly decreased graft forces compared with the ALC-sectioned state ( P = .019). Finally, ALC sectioning did not significantly increase ACL graft load compared with the ACLR-only condition ( P = .320), nor did it exacerbate the effects of increased PTS on ATT and IR. Conclusion: LET effectively reduces ACL graft forces and improves knee stability in the presence of increased PTS, performing comparably to or better than SRO under simulated pivot-shift conditions. Clinical Relevance: These findings suggest that LET is a viable alternative to SRO, particularly for patients with high PTS undergoing ACLR.

中文翻译：

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在胫骨后坡增加的情况下，与斜面缩小截骨术相比，外侧关节外肌腱固定术对前交叉韧带移植力和膝关节稳定性的影响

背景：在胫骨后斜 （PTS） 过大的情况下，前交叉韧带 （ACL） 重建 （ACLR） 是 ACL 移植力增加和移植失败风险增加的公认危险因素。目的/假设： 本研究的主要目的是评估外侧关节外肌腱固定术 （LET） 是否可以减轻 PTS 增加对膝关节运动学和 ACL 移植力的不利影响，取得与减斜截骨术 （SRO） 相当的结果。据推测，在 PTS 增加的情况下，LET 将在膝关节稳定性和移植物力降低方面提供与 SRO 类似的改善。次要目的是确定 ALC 损伤是否加剧了 PTS 增加对 ACL 移植力和整体膝关节稳定性的影响。据推测，ALC 损伤会放大 PTS 增加的负面影响。研究设计： 对照实验室研究。方法： 制备 8 例新鲜冷冻尸体标本，不包括既往手术史或有明显膝关节病变的尸体标本。使用四重腘绳肌腱自体移植物进行 ACLR。在不同程度的 PTS （0°、10° 和 20°） 下测试 LET 和 SRO 的效果。模拟枢轴移位作用于测量 ACL 移植物负荷、胫骨前平移 （ATT） 和内旋 （IR）。采用混合效应模型分析数据。结果： 增加 PTS 导致 ACL 移植力 （ P < .001 ）、ATT （ P < .001） 和 IR （ P < .001） 显著增加。LET 在 PTS 的 10° 处将 ACL 移植物负荷降低了 22.1%，在 PTS 的 20° 处降低了 36.6%。相比之下，10° SRO 在 PTS 的 10° 处仅减少 2.6%，在 20° 处仅减少 23.9%。 在胫骨斜度 10° 和 20° 处，截骨术后状态和 LET 增强状态之间的移植物力没有显著差异，表明在减少移植物负荷方面具有同等功效。此外，与 ALC 切片状态相比，LET 显着降低了移植物力 （ P = .019）。最后，与仅 ACLR 条件 （P = .320） 相比，ALC 切片没有显着增加 ACL 移植物负荷，也没有加剧 PTS 增加对 ATT 和 IR 的影响。结论：在 PTS 增加的情况下，LET 有效降低 ACL 移植力并提高膝关节稳定性，在模拟枢轴移位条件下的性能与 SRO 相当或更好。临床相关性：这些发现表明 LET 是 SRO 的可行替代方案，特别是对于接受 ACLR 的高 PTS 患者。