Knee-extensor strength, symptoms, and need for surgery after two, four, or six exercise sessions/week using a home-based one-exercise program: a randomized dose-response trial of knee-extensor resistance exercise in patients eligible for knee replacement (the QUADX-1 trial)

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.

The relationship between prescribed pre-operative knee-extensor exercise dosage and effect on knee-extensor strength prior to and following total knee arthroplasty: a systematic review and meta-regression analysis of randomized controlled trials

OBJECTIVE

The aim of this systematic review was to evaluate the relationship between prescribed knee-extensor strength exercise dosage in pre-operative exercise intervention and the effect on knee-extensor muscle strength prior to and following TKA. Additional meta-analyses report the effect of pre-habilitation on outcomes prior to and following TKA.

DESIGN

A systematic literature search was performed including RCT's evaluating the effect of pre-operative exercise prior to and following TKA. Meta-regression analysis was performed to evaluate the dose-response relationship between prescribed exercise dose and the pooled effect, measured as standardized mean difference (SMD). The prescribed exercise dose was quantified using a formula accounting for as many exercise descriptors as possible. Risk of bias in the included trials was assessed using the Cochrane Risk of Bias Tool.

RESULTS

Twelve trials with 616 patients were included. Meta-regression analysis showed no relationship between prescribed pre-operative knee-extensor exercise dosage and change in knee-extensor strength neither prior to (slope 0.0005 [95%CI -0.007 to 0.008]) or 3 months following TKA (slope 0.0014 [95%CI -0.006 to 0.009]). Prior to TKA, a moderate effect favoring pre-operative exercise for increase in knee-extensor strength was found (SMD 0.50 [95%CI 0.12 to 0.88]), but not at 3 months following TKA (SMD -0.01 [95%CI -0.45 to 0.43]). Risk of bias was generally assessed as unclear.

CONCLUSION

Meta-regression analysis of existing trials suggests no relationship between the prescribed pre-operative knee-extensor exercise dosage and the change in knee-extensor strength observed prior to and following TKA. Pre-operative exercise including knee-extensor muscle strength exercise increased knee-extensor strength moderately prior to but not 3 months following TKA.

PROTOCOL REGISTRATION

PROSPERO ID (CRD42018076308) (http://www.crd.york.ac.uk/PROSPERO/).