No effects of functional exercise therapy on walking biomechanics in patients with knee osteoarthritis: exploratory outcome analyses from a randomised trial

Exercise for knee osteoarthritis pain: Association or causation?

Exercise is universally recommended as a primary strategy for the management of knee osteoarthritis (OA) pain. The recommendations are based on results from more than 100 randomized controlled trials (RCTs) that compare exercise to no-attention control groups. However, due to the inherent difficulties with adequate placebo control, participant blinding and the use of patient-reported outcomes, the existing RCT evidence is imperfect. To better understand the evidence used to support a causal relationship between exercise and knee OA pain relief, we examined the existing evidence through the Bradford Hill considerations for causation. The Bradford Hill considerations, first proposed in 1965 by Sir Austin Bradford Hill, provide a framework for assessment of possible causal relationships. There are 9 considerations by which the evidence is reviewed: Strength of association, Consistency, Specificity, Temporality, Biological Gradient (Dose-Response), Plausibility, Coherence, Experiment, and Analogy. Viewing the evidence from these 9 viewpoints did neither bring forward indisputable evidence for nor against the causal relationship between exercise and improved knee OA pain. Rather, we conclude that the current evidence is not sufficient to support claims about (lack of) causality. With our review, we hope to advance the continued global conversation about how to improve the evidence-based management of patients with knee OA.

Eight weeks of a lower limb resistance training protocol and gait performance in patients with symptomatic mild to moderate knee osteoarthritis

BACKGROUND

The role of strengthening the lower limbs to optimize the biomechanics of the hip, knee and ankle during walking in patients with knee osteoarthritis, is still unclear. This study aimed to analyse the walking biomechanics of individuals with symptomatic mild to moderate knee osteoarthritis before and after a simplified lower limb resistance training protocol, focused on knee joint exercises with individualized load.

METHODS

Forty-one patients with symptomatic and radiographic mild to moderate knee osteoarthritis underwent 3D gait analysis pre-post 8 weeks lower limb resistance training protocol performed 3 times a week. Parameters investigated were spatiotemporal, sagittal range of motion, flexion and extension minimum and maximum values, power and moment of hip, knee and ankle, as well as self-reported pain and physical function by the Western Ontario MacMaster University Osteoarthritis Index. Paired t test, Wilcoxon, Spearman's correlation and a logistic model were used for statistical analysis, with p < 0.05. Pain improvement more than 2 points was considered clinically relevant. The effect size (ES) was calculated using Cohen's d.

RESULTS

Post protocol walking speed increased 6.7% (ES: 0.711), cadence 3.7% (ES: 0.655), stride length 2.6% (ES: 0.542), and double support time reduced 6.9% (ES:0.459). It was also observed a significant increase in one maximum repetition test for legpress 46%, knee extension 23% and knee flexion chair 27% (p < 0.001). Patients reported a 62.5% reduction in pain (ES:1.518) and 64.9% improvement in physical function (ES:1.376). 82% of the patients presented more than 2 points improvement in pain. No evidence of strong correlations between pain, strength gains and gait parameters were found.

CONCLUSIONS

There was a significant and clinical improvement of spatiotemporal gait parameters, pain, physical function, and strength after 8-week lower limb resistance training protocol. Patients who had a clinically relevant pain improvement presented better gait performance.

Exploring the modification factors of exercise therapy on biomechanical load in patients with knee osteoarthritis: a systematic review and meta-analysis

The objective of this systematic review and meta-analysis is to clarify the effect of exercise therapy on the first peak knee adduction moment (KAM), as well as other biomechanical loads in patients with knee osteoarthritis (OA), and identify physical characteristics that influence differences in biomechanical load after exercise therapy. The data sources are PubMed, PEDro, and CINAHL, from study inception to May 2021. The eligibility criteria include studies evaluating the first peak (KAM), peak knee flexion moment (KFM), maximal knee joint compression force (KCF), or co-contraction during walking before and after exercise therapy in patients with knee OA. The risk of bias was independently assessed by two reviewers using PEDro and NIH scales. Among 11 RCTs and nine non-RCTs, 1119 patients with knee OA were included (average age: 63.7 years). As the results of meta-analysis, exercise therapy tended to increase the first peak KAM (SMD 0.11; 95% CI: -0.03-0.24), peak KFM (SMD 0.13; 95% CI: -0.03-0.29), and maximal KCF (SMD 0.09; 95% CI -0.05-0.22). An increased first peak KAM was significantly associated with a larger improvement in knee muscle strength and WOMAC pain. However, the quality of evidence regarding the biomechanical loads was low-to-moderate according to the GRADE approach. The improvement in pain and knee muscle strength may mediate the increase in first peak KAM, suggesting difficulty in balancing symptom relief and biomechanical load reduction. Therefore, exercise therapy may satisfy both aspects simultaneously when combined with biomechanical interventions, such as a valgus knee brace or insoles. Registration: PROSPERO (CRD42021230966).

Targeted exercises can improve biomechanical markers in individuals with knee osteoarthritis: A secondary analysis from a cluster randomized controlled trial

BACKGROUND

It is not clear whether exercise therapy significantly improves knee biomechanics during gait in osteoarthritis (OA) patients. This study aimed to determine whether targeted exercises based on a knee kinesiography exam improve biomechanical markers (BMs) compared with conventional primary care (CPC) management.

METHODS

This was a secondary analysis of a cluster randomized controlled trial in which patients were assigned to one of three groups: (1) Control (CPC), (2) Exercise, and (3) Exercise&Education. Fourteen known BMs in knee OA patients were assessed. The primary outcome was the global evolution ratio (GER), which was calculated as the sum of improved BMs over the sum of deteriorated BMs 6 months after baseline assessment. GER scores were categorized with three different sets of cut-off values into clinical levels: (a) Deteriorated, (b) Stabilized, and (c) Improved. Ordinal logistic regressions were performed on the per-protocol population to determine whether there was a relationship between group assignment and GER levels.

RESULTS

Of the 221 eligible participants, 163 were included. Two different regression models showed that patients from Group 3 (Exercise&Education) were 2.5-times more likely to be in an upper GER level (i.e., Stabilized or Improved) than patients from the control group (both odds ratio (OR) > 2.46, Wald Χ²(1) ≥ 7.268, P ≤ 0.01). They also reported significantly more improvement in pain and function (Knee Injury and Osteoarthritis Outcome Score, both P ≤ 0.01).

CONCLUSIONS

Results suggest that targeted exercises can improve biomechanical markers in knee OA patients compared with CPC treatment. Further studies are needed to confirm these findings and refine the biomechanical markers to address to maximize patients' clinical outcomes.

Changes in medial-to-lateral knee joint loading patterns assessed by Dual-Energy X-ray Absorptiometry following supervised neuromuscular exercise therapy and patient education in patients with knee osteoarthritis: an exploratory cohort study

BACKGROUND

The mechanisms underlying pain reductions following exercise therapy in patients with knee osteoarthritis (OA) are poorly understood. One mechanism could be changes in mechanical knee joint loading.

OBJECTIVE

To investigate if a neuromuscular exercise therapy and patient education intervention could alter knee joint loading assessed by Dual-Energy X-ray Absorptiometry (DXA) in people with knee OA.

METHODS

Participants with symptomatic knee OA were evaluated before and 26 weeks after an 8-week supervised neuromuscular exercise therapy and patient education intervention (Good Life with OsteoArthritis in Denmark). DXA scans were used to estimate the medial-to-lateral tibial plateau bone mineral density (BMD) ratio. The Knee Injury and Osteoarthritis Outcome Score was used to assess improvements in knee pain, symptoms, physical function, and knee-related quality of life. Changes in physical function were assessed with the 30-second chair stand test and the 40-meter fast paced walk test.

RESULTS

Of 42 participants recruited, 30 (21 females, mean age 64 ± 7.9 years) had full data available. Medial-to-lateral tibial BMD ratio increased non-significantly by 0.02 (95% CI -0.01 to 0.06) (indicating higher medial load) from baseline to 26-weeks follow-up. Participants had statistically significant improvements of 21% in pain, 17% in symptoms, 14% in ADL, 17% in knee-related quality of life, 13% in chair stand ability, and 6% in walking speed.

CONCLUSIONS

In this exploratory cohort study, following an 8-weeks supervised exercise therapy and patient education intervention, the medial-to-lateral tibial BMD ratio did not seem to change.

Effects of resistance training on gait velocity and knee adduction moment in knee osteoarthritis patients: a systematic review and meta-analysis

The systematic review aimed to analyze the effects of resistance training in knee osteoarthritis (OA) rehabilitation from a biomechanical perspective. A meta-analysis was performed to determine the potential benefits of resistance training on patients with knee OA. Relevant studies based on the inclusion and exclusion criteria were selected from CENTRAL, PubMed, Scopus, and Web of Science databases inception to August 2020. Outcome measures included gait velocity and knee adduction moment (KAM). The mean differences of the data with a 95% confidence interval were analyzed using STATA 15.1 software The search identified eight studies that satisfied all the inclusion criteria, in which 164 patients were involved in gait velocity studies and another 122 patients were part of KAM studies. Analysis of the pooled data showed that resistance training significantly improved the gait velocity in patients with knee OA (p < 0.01, z = 2.73), ES (95% CI) = 0.03 (0.01, 0.06) m/s. However, resistance training had no significant effect on improving KAM in patients with knee OA (p = 0.98, z = 0.03), ES (95% CI) = 0.00 (− 0.16, 0.16) percentage of body weight × height (%BW × Ht). Therefore, resistance training may enhance gait velocity but not KAM in knee OA patients. The protocol was registered at PROSPERO (registration number: CRD42020204897).

Relative Efficacy of Different Exercises for Pain, Function, Performance and Quality of Life in Knee and Hip Osteoarthritis: Systematic Review and Network Meta-Analysis

Background

Guidelines recommend exercise as a core treatment for osteoarthritis (OA). However, it is unclear which type of exercise is most effective, leading to inconsistency between different recommendations.

Objectives

The aim of this systematic review and network meta-analysis was to investigate the relative efficacy of different exercises (aerobic, mind–body, strengthening, flexibility/skill, or mixed) for improving pain, function, performance and quality of life (QoL) for knee and hip OA at, or nearest to, 8 weeks.

Methods

We searched nine electronic databases up until December 2017 for randomised controlled trials that compared exercise with usual care or with another exercise type. Bayesian network meta-analysis was used to estimate the relative effect size (ES) and corresponding 95% credibility interval (CrI) (PROSPERO registration: CRD42016033865).

Findings

We identified and analysed 103 trials (9134 participants). Aerobic exercise was most beneficial for pain (ES 1.11; 95% CrI 0.69, 1.54) and performance (1.05; 0.63, 1.48). Mind–body exercise, which had pain benefit equivalent to that of aerobic exercise (1.11; 0.63, 1.59), was the best for function (0.81; 0.27, 1.36). Strengthening and flexibility/skill exercises improved multiple outcomes at a moderate level. Mixed exercise was the least effective for all outcomes and had significantly less pain relief than aerobic and mind–body exercises. The trend was significant for pain (p = 0.01), but not for function (p = 0.07), performance (p = 0.06) or QoL (p = 0.65).

Conclusion

The effect of exercise varies according to the type of exercise and target outcome. Aerobic or mind–body exercise may be the best for pain and function improvements. Strengthening and flexibility/skill exercises may be used for multiple outcomes. Mixed exercise is the least effective and the reason for this merits further investigation.

Electronic supplementary material

The online version of this article (10.1007/s40279-019-01082-0) contains supplementary material, which is available to authorized users.

Portable Normothermic Cardiac Perfusion System in Donation After Cardiocirculatory Death: A Health Technology Assessment

BACKGROUND

Heart transplantation is the most effective treatment for people experiencing end-stage heart failure whose quality of life and life expectancy are unacceptable. However, there is a chronic shortage of donor hearts to meet the demand, so it is essential to expand the donor pool and increase supply. Heart donation mainly occurs after brain death (neurological determination of death [NDD]), but it may also be feasible after cardiocirculatory death (when the heart has stopped beating and there is no longer blood flow or a pulse), provided specialized preservation techniques are used. An investigational device, a portable normothermic cardiac perfusion system, could make it possible to procure, preserve, and transport hearts donated after cardiocirculatory death (DCD). We conducted a health technology assessment of a portable normothermic cardiac perfusion system for the preservation and transportation of DCD hearts for adult transplantation. This included an evaluation of the effectiveness, safety, value for money, and budget impact of publicly funding this system, as well as an evaluation of patient preferences and values.

METHODS

We performed a systematic review of the clinical literature published since 1998 that examined the clinical safety and effectiveness of a portable normothermic cardiac perfusion system for DCD heart transplantation. We assessed the risk of bias of each included study and the quality of the body of evidence according to the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) Working Group criteria. We also reviewed the economic evidence published during the same time period for the cost-effectiveness of a portable normothermic cardiac perfusion system for DCD hearts compared with cold storage for NDD hearts. We further estimated the 5-year net budget impact of publicly funding a normothermic cardiac perfusion system for DCD heart transplantation for adults on Ontario's waitlist. To contextualize the potential value of a portable normothermic cardiac perfusion system, we spoke with people waiting for a heart transplant, people who had received a heart transplant, and family members of organ donors.

RESULTS

We screened 2,386 clinical citations. One study and two case reports met the inclusion criteria. The survival of recipients of DCD hearts procured with a portable normothermic cardiac perfusion system did not differ significantly from the survival of recipients of hearts donated after NDD at 30 days or 90 days, nor was there a significant difference in cumulative survival at 1 year post-transplant (GRADE: Very Low). The occurrence of rejection and graft failure also did not significantly differ between the groups (GRADE: Very Low). Cardiac function in the early post-operative period was better in DCD hearts than NDD hearts (GRADE: Very Low). There were no differences in outcomes between DCD procurement techniques.The economic literature search yielded 62 citations. One report met the inclusion criteria but was not directly applicable to the Ontario context. Given the lack of clinical and economic evidence on long-term outcomes, we did not conduct a primary economic evaluation. In the budget impact analysis, based on the number of DCD donors under 40 years of age in the last 5 years, we estimated that the increased availability of donor hearts made possible by the technology would result in an additional seven transplants in year 1, increasing to 12 in year 5. The annual net budget impact of publicly funding a normothermic cardiac perfusion system for the transplantation of DCD hearts in Ontario over the next 5 years is about $2.0 million in the first year and about $0.9 million in each of years 2 through 5, yielding a total net budget impact of about $5.6 million. This number increases to about $10.3 million if the transplant volume increases to 18 hearts in year 1 (meaning a subsequent increase of up to 21 hearts in year 5). If transplantation were limited to people who do not qualify for a ventricular assistive device or who qualify but do not wish to receive one, the total 5-year net budget impact would be about $7.9 million.People waiting for a heart transplant or who had received a heart transplant and family members of organ donors expressed no substantial concerns about the potential use of a portable normothermic cardiac perfusion system. They hope that it may increase the number of donor hearts available for transplant. For family members of organ donors, a perfusion system may provide comfort and value if it can increase the successful procurement of donor hearts.

CONCLUSIONS

Based on very low quality of evidence, the outcomes for recipients of DCD hearts preserved using a portable normothermic cardiac perfusion system appear to be similar to outcomes for recipients of NDD hearts. Owing to a lack of evidence relevant to the Ontario context, we were unable to determine whether a portable normothermic perfusion system may be cost-effective. We estimate that publicly funding a portable normothermic cardiac perfusion system for DCD heart transplantation over the next 5 years will cost about $5.6 million. The people we spoke with believe that the system may increase the number of hearts available for transplant and therefore increase the number of heart transplants that can be done.

Structured Education and Neuromuscular Exercise Program for Hip and/or Knee Osteoarthritis: A Health Technology Assessment

BACKGROUND

Osteoarthritis is a chronic disorder and the most common form of arthritis. The joints most commonly affected are the hip and knee. The progression of osteoarthritis results in the breakdown of tissues and cartilage and the loss of joint function, causing symptoms such as pain, stiffness, reduced physical function, and limited movement. Although there is no cure for osteoarthritis, treatment options are available to manage symptoms and optimize quality of life. Clinical guidelines recommend education, exercise, and weight loss (when necessary) as the first line of treatment.

METHODS

We conducted a health technology assessment, which included an evaluation of the effectiveness, safety, and cost-effectiveness of a structured education and neuromuscular exercise program for the management of hip and/or knee osteoarthritis. We also assessed the budget impact of publicly funding such a program, and we spoke with people with osteoarthritis to gain an understanding of their preferences and values. We performed a systematic review of the clinical and economic literature published between January 1, 2008, and October 4, 2017. We also performed a grey literature search of health technology assessment websites. We assessed the risk of bias of each study, and we assessed the quality of the body of evidence according to the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) Working Group criteria. To evaluate the cost-effectiveness of a structured education and neuromuscular exercise program for adults with knee osteoarthritis, we conducted a cost-utility analysis from the perspective of the Ontario Ministry of Health and Long-Term Care. We also estimated the budget impact of publicly funding such a program in Ontario over the next 5 years. To contextualize the potential value of this type of program as a treatment option, we spoke with people with hip and/or knee osteoarthritis.

RESULTS

Ten studies met our inclusion criteria for the clinical evidence review. Compared with usual care, a structured education and neuromuscular exercise program showed statistically significant short-term improvements in pain (GRADE low) and physical function (GRADE moderate), as well as statistically significant long-term improvements in performing activities of daily living (GRADE moderate) and in quality of life (GRADE moderate). The short-term improvements in pain and physical function appeared to be sustained into the medium term. Compared with patient education, a structured education and neuromuscular exercise program showed statistically significant short-term improvements in pain (GRADE low) and physical function (GRADE low) and sustained long-term improvement in physical function.Our primary economic evaluation showed that, compared with usual care, a group-based structured education and neuromuscular exercise program consisting of two educational sessions and 24 exercise sessions for the management of knee osteoarthritis was associated with an incremental cost of $719 (95% confidence interval [CI]: $410-$1,118) and an incremental quality-adjusted survival of 0.03 quality-adjusted life-years (QALYs) (95% CI: -0.006 to 0.06), resulting in an incremental cost-effectiveness ratio (ICER) of $23,967 per QALY gained. The budget impact of publicly funding a group-based structured education and neuromuscular exercise program consisting of two educational sessions and 24 exercise sessions would range from $21.4 million to $91.6 million per year over the next 5 years. The budget impact of publicly funding a program consisting of two educational sessions and 12 exercise sessions would range from $12.4 million to $53.2 million per year over the next 5 years.People with hip and/or knee osteoarthritis with whom we spoke reported on the negative impact of osteoarthritis on their physical functioning and quality of life. Those with experience of a structured education and neuromuscular exercise program reported favourably on the program, stating they felt that participation in the program had strengthened their muscles and reduced the negative impact of their symptoms. The cost of such programs was reported as a barrier to access.

CONCLUSIONS

There is moderate-quality evidence that, compared with usual care, a structured education and neuromuscular exercise program improves physical function, quality of life, and the ability to perform activities of daily living. There is low-quality evidence that, compared with usual care, this type of program improves pain. Low-quality evidence suggests that, compared with patient education, a structured education and neuromuscular exercise program improves pain and physical function.A group-based structured education and neuromuscular exercise program may be cost-effective for the nonsurgical management of knee osteoarthritis. Publicly funding a group-based structured education and neuromuscular exercise program for hip and/or knee osteoarthritis in Ontario would lead to additional costs to the health system of $21.4 million to $91.6 million per year over the next 5 years. If the program could be delivered with a smaller number of 12 exercise sessions, the budget impact would be reduced to between $12.4 million and $53.2 million over the next 5 years.Structured education and neuromuscular exercise programs are perceived favourably by people with hip and/or knee osteoarthritis. However, the cost of such programs may be a barrier to access.

Wearable Sensor Data to Track Subject-Specific Movement Patterns Related to Clinical Outcomes Using a Machine Learning Approach

Wearable sensors can provide detailed information on human movement but the clinical impact of this information remains limited. We propose a machine learning approach, using wearable sensor data, to identify subject-specific changes in gait patterns related to improvements in clinical outcomes. Eight patients with knee osteoarthritis (OA) completed two gait trials before and one following an exercise intervention. Wearable sensor data (e.g., 3-dimensional (3D) linear accelerations) were collected from a sensor located near the lower back, lateral thigh and lateral shank during level treadmill walking at a preferred speed. Wearable sensor data from the 2 pre-intervention gait trials were used to define each individual’s typical movement pattern using a one-class support vector machine (OCSVM). The percentage of strides defined as outliers, based on the pre-intervention gait data and the OCSVM, were used to define the overall change in an individual’s movement pattern. The correlation between the change in movement patterns following the intervention (i.e., percentage of outliers) and improvement in self-reported clinical outcomes (e.g., pain and function) was assessed using a Spearman rank correlation. The number of outliers observed post-intervention exhibited a large association (ρ = 0.78) with improvements in self-reported clinical outcomes. These findings demonstrate a proof-of-concept and a novel methodological approach for integrating machine learning and wearable sensor data. This approach provides an objective and evidence-informed way to understand clinically important changes in human movement patterns in response to exercise therapy.