Department of Orthopaedics and Traumatology, University Hospital Basel, Spitalstrasse 21, Basel, 4031, Switzerland.
Department of Biomedical Engineering, University of Basel, Allschwil, 4123, Switzerland.
BMC Musculoskelet Disord. 2023 Oct 4;24(1):785. doi: 10.1186/s12891-023-06916-7.
Little is known about knee mechanics and muscle control after augmented ACL repair. Our aim was to compare knee biomechanics and leg muscle activity during walking between the legs of patients 2 years after InternalBrace-augmented anterior cruciate ligament repair (ACL-IB) and between patients after ACL-IB and ACL reconstruction (ACL-R), and controls.
Twenty-nine ACL-IB, 27 sex- and age-matched ACL-R (hamstring tendon autograft) and 29 matched controls completed an instrumented gait analysis. Knee joint angles, moments, power, and leg muscle activity were compared between the involved and uninvolved leg in ACL-IB (paired t-tests), and between the involved legs in ACL patients and the non-dominant leg in controls (analysis of variance and posthoc Bonferroni tests) using statistical parametric mapping (SPM, P < 0.05). Means and 95% confidence intervals (CI) of differences in discrete parameters (DP; i.e., maximum/minimum) were calculated.
Significant differences were observed in ACL-IB only in minimum knee flexion angle (DP: 2.4°, CI [-4.4;-0.5]; involved > uninvolved) and maximum knee flexion moment during stance (-0.07Nm/kg, CI [-0.13;-0.00]; involved < uninvolved), and differences between ACL-IB and ACL-R only in maximum knee flexion during swing (DP: 3.6°, CI [0.5;7.0]; ACL-IB > ACL-R). Compared to controls, ACL-IB (SPM: 0-3%GC, P = 0.015; 98-100%, P = 0.016; DP: -6.3 mm, CI [-11.7;-0.8]) and ACL-R (DP: -6.0 mm, CI [-11.4;-0.2]) had lower (maximum) anterior tibia position around heel strike. ACL-R also had lower maximum knee extension moment (DP: -0.13Nm/kg, CI [-0.23;-0.02]) and internal knee rotation moment (SPM: 34-41%GC, P < 0.001; DP: -0.03Nm/kg, CI [-0.06;-0.00]) during stance, and greater maximum semitendinosus activity before heel strike (DP: 11.2%maximum voluntary contraction, CI [0.1;21.3]) than controls.
Our results suggest comparable ambulatory knee function 2 years after ACL-IB and ACL-R, with ACL-IB showing only small differences between legs. However, the differences between both ACL groups and controls suggest that function in the involved leg is not fully recovered and that ACL tear is not only a mechanical disruption but also affects the sensorimotor integrity, which may not be restored after surgery. The trend toward fewer abnormalities in knee moments and semitendinosus muscle function during walking after ACL-IB warrants further investigation and may underscore the importance of preserving the hamstring muscles as ACL agonists.
Level III, case-control study.
clinicaltrials.gov, NCT04429165 (12/06/2020).
关于增强 ACL 修复后膝关节力学和肌肉控制的知识有限。我们的目的是比较 2 年后接受 InternalBrace 增强前交叉韧带修复（ACL-IB）的患者和 ACL-IB 与 ACL 重建（ACL-R）患者以及对照组之间的步行时膝关节生物力学和腿部肌肉活动。
29 例 ACL-IB、27 例 ACL-R（腘绳肌腱自体移植物）和 29 例匹配的对照组完成了仪器步态分析。在 ACL-IB 中，通过配对 t 检验比较受累腿和未受累腿之间的关节角度、力矩、功率和腿部肌肉活动（配对 t 检验），以及 ACL 患者受累腿和对照组非优势腿之间的差异（方差分析和事后 Bonferroni 检验）使用统计参数映射（SPM，P<0.05）。使用离散参数（DP；即最大/最小）计算差异的平均值和 95%置信区间（CI）。
仅在 ACL-IB 中观察到显著差异，即站立位最小膝关节屈曲角度（DP：2.4°，CI [-4.4;-0.5]；受累>未受累）和站立位最大膝关节屈曲力矩（-0.07Nm/kg，CI [-0.13;-0.00]；受累<未受累），以及 ACL-IB 和 ACL-R 之间的差异仅在摆动位最大膝关节屈曲时（DP：3.6°，CI [0.5;7.0]；ACL-IB>ACL-R）。与对照组相比，ACL-IB（SPM：0-3%GC，P=0.015；98-100%，P=0.016；DP：-6.3mm，CI [-11.7;-0.8]）和 ACL-R（DP：-6.0mm，CI [-11.4;-0.2]）在足跟撞击时胫骨前位置较低（最大）。ACL-R 在站立位时的最大膝关节伸展力矩（DP：-0.13Nm/kg，CI [-0.23;-0.02]）和内膝旋转力矩（SPM：34-41%GC，P<0.001；DP：-0.03Nm/kg，CI [-0.06;-0.00]）也较低，并且在足跟撞击前的半腱肌活动较大（DP：11.2%最大自主收缩，CI [0.1;21.3]）与对照组相比。
我们的结果表明，ACL-IB 和 ACL-R 后 2 年的步行膝关节功能相当，ACL-IB 双腿之间仅存在较小差异。然而，两组 ACL 患者与对照组之间的差异表明，受累腿的功能尚未完全恢复，ACL 撕裂不仅是机械性破坏，还会影响感觉运动完整性，这可能无法在手术后恢复。ACL-IB 后步行时膝关节力矩和半腱肌功能异常减少的趋势需要进一步研究，这可能强调了保留 ACL 内收肌作为 ACL 激动剂的重要性。
III 级，病例对照研究。
clinicaltrials.gov，NCT04429165（2020 年 12 月 6 日）。
