Objective

To investigate firstly the efficacy of three different dosages of one home-based, knee-extensor resistance exercise on knee-extensor strength in patients eligible for knee replacement, and secondly, the influence of exercise on symptoms, physical function and decision on surgery.

Method

One-hundred and forty patients eligible for knee replacement were randomized to three groups: 2, 4 or 6 home-based knee-extensor resistance exercise-sessions per week (group 2, 4 and 6 respectively) for 12 weeks. Primary outcome: isometric knee-extensor strength. Secondary outcomes: Oxford Knee Score, Knee injury and Osteoarthritis Outcome Score, average knee pain last week (0–10 numeric rating scale), 6-min walk test, stair climbing test, exercise adherence and “need for surgery”.

Results

Primary analysis: Intention-to-treat analysis of 140 patients did not find statistically significant differences between the groups from baseline to after 12 weeks of exercise in isometric knee-extensor strength: Group 2 vs 4 (0.003 Nm/kg (0.2%) [95% CI -0.15 to 0.15], P = 0.965) and group 4 vs 6 (−0.04 Nm/kg (−2.7%) [95% CI -0.15 to 0.12], P = 0.628). Secondary analysis: Intention-to-treat analyses showed statistically significant differences between the two and six sessions/week groups in favor of the two sessions/week group for Oxford Knee Score: 4.8 OKS points (15.2%) [1.3 to 8.3], P = 0.008) and avg. knee pain last week (NRS 0–10): −1.3 NRS points (−19.5%) [-2.3 to −0.2], P = 0.018. After the 12-week exercise intervention, data were available for 117 patients (N = 39/group): 38 (32.5%) patients wanted surgery and 79 (67.5%) postponed surgery. This was independent of exercise dosage.

Conclusion

In patients eligible for knee-replacement we found no between-group differences in isometric knee extensor strength after 2, 4 and 6 knee-extensor resistance exercise sessions per week. We saw no indication of an exercise dose–response relationship for isometric knee-extensor strength and only clinically irrelevant within group changes. For some secondary outcome (e.g., KOOS subscales) we found clinically relevant within group changes, which could help explain why only one in three patients decided to have surgery after the simple home-based exercise intervention.

Trial registration

ClinicalTrials.gov identifier: NCT02931058. Preprint: https://doi.org/10.1101/2021.04.07.21254965.

中文翻译：

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膝关节伸肌力量、症状和每周两次、四次或六次锻炼后的手术需求，使用以家庭为基础的单次锻炼计划：在符合膝关节置换条件的患者中进行膝伸肌阻力锻炼的随机剂量反应试验（QUADX-1 试验）

客观的

首先研究三种不同剂量的一种家庭式膝伸肌阻力运动对符合膝关节置换条件的患者的膝伸肌力的疗效，其次研究运动对症状、身体功能和手术决策的影响。

方法

140 名符合膝关节置换条件的患者被随机分为三组：每周 2、4 或 6 次家庭膝关节伸肌阻力训练（分别为第 2、4 和 6 组），持续 12 周。主要结果：等长膝伸肌力量。次要结果：牛津膝关节评分、膝关节损伤和骨关节炎结果评分、上周平均膝关节疼痛（0-10 数字评分量表）、6 分钟步行测试、爬楼梯测试、运动依从性和“需要手术”。

结果

主要分析：对 140 名患者的意向治疗分析未发现从基线到 12 周运动后等长膝伸肌力量组之间的统计学显着差异：第 2 组与第 4 组（0.003 Nm/kg (0.2%) [ 95% CI -0.15 至 0.15]，P  = 0.965）和第 4 组与第 6 组（-0.04 Nm/kg (-2.7%) [95% CI -0.15 至 0.12]，P  = 0.628）。二次分析：意向治疗分析显示，2 次和 6 次/周组之间存在统计学显着差异，牛津膝关节评分优于 2 次/周组：4.8 OKS 点 (15.2%) [1.3 至 8.3]，P  = 0.008) 和平均值。上周膝关节疼痛（NRS 0-10）：-1.3 NRS 点（-19.5%）[-2.3 至 -0.2]，P = 0.018。在 12 周的运动干预后，117 名患者（N = 39/组）的数据可用：38 名（32.5%）患者想要手术，79 名（67.5%）患者推迟手术。这与运动剂量无关。

结论

在符合膝关节置换条件的患者中，我们发现每周 2、4 和 6 次膝关节伸肌阻力锻炼后等长膝关节伸肌力量没有组间差异。我们没有看到等长膝伸肌力量的运动剂量 - 反应关系的迹象，只有在组变化中临床上不相关。对于一些次要结果（例如，KOOS 子量表），我们发现在组变化中具有临床相关性，这有助于解释为什么只有三分之一的患者在简单的家庭运动干预后决定进行手术。

试用注册

ClinicalTrials.gov 标识符：NCT02931058。预印本：https://doi.org/10.1101/2021.04.07.21254965。