Background:

Early tensile loading improves material properties of healing Achilles tendon ruptures in animal models and in surgically treated human ruptures. However, the effect of such rehabilitation in patients who are nonsurgically treated remains unknown.

Hypothesis:

In nonsurgically treated Achilles tendon ruptures, early tensile loading would lead to higher elastic modulus 19 weeks after the injury compared with controls.

Study Design:

Randomized controlled trial; Level of evidence, 2.

Methods:

Between October 2015 and November 2018, a total of 40 nonsurgically treated patients with acute Achilles tendon rupture were randomized to an early tensile loading (loaded group) or control group. Tantalum bead markers were inserted percutaneously into the tendon stumps 2 weeks after the injury to allow high-precision measurements of callus deformation under mechanical testing. The loaded group used a training pedal twice daily to produce a gradual increase in tensile load during the following 5 weeks. Both groups were allowed full weightbearing in an ankle orthosis and unloaded range of motion exercises. Patients were followed clinically and via roentgen stereophotogrammetric analysis and computed tomography at 7, 19, and 52 weeks after the injury.

Results:

The mean ± standard deviation elastic modulus at 19 weeks was 95.6 ± 38.2 MPa in the loaded group and 108 ± 45.2 MPa in controls (P = .37). The elastic modulus increased in both groups, although it was lower in the loaded group at all time points. Tendon cross-sectional area increased from 7 weeks to 19 weeks, from 231 ± 99.5 to 388 ± 142 mm² in the loaded group and from 188 ± 65.4 to 335 ± 87.2 mm² in controls (P < .001 for the effect of time). Cross-sectional area for the loaded group versus controls at 52 weeks was 302 ± 62.4 mm² versus 252 ± 49.2 mm², respectively (P = .03). Gap elongation was 7.35 ± 13.9 mm in the loaded group versus 2.86 ± 5.52 mm in controls (P = .27).

Conclusion:

Early tensile loading in nonsurgically treated Achilles tendon ruptures did not lead to higher elastic modulus in the healing tendon but altered the structural properties of the tendon via an increased tendon thickness.

Registration:

NCT0280575 (ClinicalTrials.gov identifier).

中文翻译：

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非手术治疗的跟腱断裂的早期拉伸载荷导致更大的肌腱愈伤组织和更低的弹性模量：一项随机对照试验

背景：

早期拉伸载荷改善了动物模型和手术治疗的人体断裂愈合跟腱断裂的材料特性。然而，这种康复对非手术治疗患者的效果仍然未知。

假设：

在非手术治疗的跟腱断裂中，与对照组相比，早期拉伸负荷会导致受伤后 19 周的弹性模量更高。

学习规划：

随机对照试验; 证据等级，2。

方法：

2015 年 10 月至 2018 年 11 月期间，共有 40 名非手术治疗的急性跟腱断裂患者被随机分配到早期拉伸负荷（负荷组）或对照组。受伤 2 周后，将钽珠标记经皮插入肌腱残端，以便在机械测试下高精度测量愈伤组织变形。负重组每天两次使用训练踏板，在接下来的 5 周内逐渐增加拉伸负荷。两组均允许在踝关节矫形器中完全负重和卸载运动范围练习。在受伤后 7、19 和 52 周时，通过伦琴立体摄影分析和计算机断层扫描对患者进行临床随访。

结果：

19 周时的平均 ± 标准偏差弹性模量在负载组中为 95.6 ± 38.2 MPa，在对照组中为 108 ± 45.2 MPa ( P = .37)。两组的弹性模量都增加了，尽管在所有时间点加载组的弹性模量都较低。肌腱横截面积从 7 周增加到 19 周，负荷组从 231 ± 99.5 增加到 388 ± 142 mm ²，对照组从 188 ± 65.4 增加到 335 ± 87.2 mm ²（时间效应P < .001 ). 52 周时负荷组和对照组的横截面积分别为 302 ± 62.4 mm ²和 252 ± 49.2 mm ² ( P=.03）。负荷组的间隙伸长为 7.35 ± 13.9 毫米，而对照组为 2.86 ± 5.52 毫米 ( P = .27)。

结论：

非手术治疗的跟腱断裂的早期拉伸负荷不会导致愈合肌腱的弹性模量更高，但会通过增加肌腱厚度改变肌腱的结构特性。

登记：

NCT0280575（ClinicalTrials.gov 标识符）。