scholarly journals Construct validity of the OCTOPuS stratification algorithm for allocating patients with knee osteoarthritis into subgroups

2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Jesper Knoop ◽  
Raymond W. J. G. Ostelo ◽  
Martin van der Esch ◽  
Arjan de Zwart ◽  
Kim L. Bennell ◽  
...  
Keyword(s):  
Muscle Strength ◽  
Construct Validity ◽  
Knee Osteoarthritis ◽  
Exercise Therapy ◽  
Research Question ◽  
A Priori ◽  
Effect Sizes ◽  
Metabolic Phenotype ◽  
Specific Exercise ◽  
Cross Sectional

Abstract Background We recently developed a model of stratified exercise therapy, consisting of (i) a stratification algorithm allocating patients with knee osteoarthritis (OA) into one of the three subgroups (‘high muscle strength subgroup’ representing a post-traumatic phenotype, ‘low muscle strength subgroup’ representing an age-induced phenotype, and ‘obesity subgroup’ representing a metabolic phenotype) and (ii) subgroup-specific exercise therapy. In the present study, we aimed to test the construct validity of this algorithm. Methods Data from five studies (four exercise therapy trial cohorts and one cross-sectional cohort) were used to test the construct validity of our algorithm by 63 a priori formulated hypotheses regarding three research questions: (i) are the proportions of patients in each subgroup similar across cohorts? (15 hypotheses); (ii) are the characteristics of each of the subgroups in line with their proposed underlying phenotypes? (30 hypotheses); (iii) are the effects of usual exercise therapy in the 3 subgroups in line with the proposed effect sizes? (18 hypotheses). Results Baseline data from a total of 1211 patients with knee OA were analyzed for the first and second research question, and follow-up data from 584 patients who were part of an exercise therapy arm within a trial for the third research question. In total, the vast majority (73%) of the hypotheses were confirmed. Regarding our first research question, we found similar proportions in each of the three subgroups across cohorts, especially for three cohorts. Regarding our second research question, subgroup characteristics were almost completely in line with the proposed underlying phenotypes. Regarding our third research question, usual exercise therapy resulted in similar, medium to large effect sizes for knee pain and physical function for all three subgroups. Conclusion We found mixed results regarding the construct validity of our stratification algorithm. On the one hand, it is a valid instrument to consistently allocate patients into subgroups that aligned our hypotheses. On the other hand, in contrast to our hypotheses, subgroups did not differ substantially in effects of usual exercise therapy. An ongoing trial will assess whether this algorithm accompanied by subgroup-specific exercise therapy improves clinical and economic outcomes.

scholarly journals POS0157-HPR CONSTRUCT VALIDITY OF THE OCTOPUS STRATIFICATION ALGORITHM FOR ALLOCATING PATIENTS WITH KNEE OSTEOARTHRITIS INTO CLINICALLY RELEVANT SUBGROUPS

2021 ◽  
Vol 80 (Suppl 1) ◽  
pp. 291.1-291
Author(s):  
J. Knoop ◽  
R. Ostelo ◽  
M. Van der Esch ◽  
A. De Zwart ◽  
K. Bennell ◽  
...  
Keyword(s):  
Muscle Strength ◽  
Knee Osteoarthritis ◽  
Exercise Therapy ◽  
Research Question ◽  
A Priori ◽  
Effect Sizes ◽  
Metabolic Phenotype ◽  
Specific Exercise ◽  
Knee Oa ◽  
Research Questions

Background:We recently developed a model of stratified exercise therapy [1], consisting of (i) a stratification algorithm allocating patients with knee osteoarthritis (OA) into clinically relevant subgroups, and (ii) subgroup-specific exercise therapy. More specifically, in our model we distinguish the following subgroups with proposed underlying phenotypes: ‘high muscle strength subgroup’ representing a post-traumatic phenotype, ‘low muscle strength subgroup’ representing an age-induced phenotype and ‘obesity subgroup’ representing a metabolic phenotype.Objectives:In the present study, we aimed to validate the construct of this algorithm, focusing on 3 research questions: (i) are the proportions of patients in each subgroup similar across cohorts?; (ii) are the characteristics of each of the subgroups in line with their proposed underlying phenotypes?; (iii) are the effects of usual exercise therapy in the 3 subgroups in line with the proposed effect sizes?Methods:Data from five studies (four trials and one cross-sectional cohort) were used to validate the construct of our algorithm by 63 a priori formulated hypotheses regarding the research questions.Results:Baseline data from a total of 1,211 patients with knee OA were analyzed for the first and second research question, and follow-up data from 584 patients who were part of an exercise arm within a trial for the third research question. In total, the vast majority (73%) of the hypotheses were confirmed. Regarding our first research question, we found similar proportions in each of the three subgroups across cohorts, especially for three cohorts. Regarding our second research question, subgroup characteristics were almost completely in line with the proposed underlying phenotypes. Regarding our third research question, unexpectedly, usual exercise therapy resulted in similar, moderate to large effect sizes for knee pain and physical function for all three subgroups.Conclusion:This study suggests that our algorithm might be a valid instrument to allocate patients with knee OA into clinically relevant subgroups, as most of our a priori hypotheses could be confirmed. On the other hand, subgroups did not differ substantially in effects of usual exercise therapy, contrary to our expectation. An ongoing trial [1] will assess whether this algorithm accompanied by subgroup-specific exercise therapy improves clinical and economic outcomes.References:[1]Knoop J, Dekker J, van der Leeden M, de Rooij M, Peter WFH, van Bodegom-Vos L, van Dongen JM, Lopuhäa N, Bennell KL, Lems WF, van der Esch M, Vliet Vlieland TPM, Ostelo RWJG. Stratified exercise therapy compared with usual care by physical therapists in patients with knee osteoarthritis: A randomized controlled trial protocol (OCTOPuS study). Physiother Res Int. 2020 Apr;25(2):e1819. doi: 10.1002/pri.1819. Epub 2019 Nov 28.Disclosure of Interests:None declared

scholarly journals The Influence of Radiographic Severity on the Relationship between Muscle Strength and Joint Loading in Obese Knee Osteoarthritis Patients

Arthritis ◽  
2011 ◽  
Vol 2011 ◽  
pp. 1-9 ◽  
Author(s):  
Jens Aaboe ◽  
Henning Bliddal ◽  
Tine Alkjaer ◽  
Mikael Boesen ◽  
Marius Henriksen
Keyword(s):  
Muscle Strength ◽  
Knee Osteoarthritis ◽  
Knee Adduction Moment ◽  
Joint Loading ◽  
Cross Sectional ◽  
Radiographic Severity ◽  
Peak Knee ◽  
The Relationship ◽  
Knee Joint Loading ◽  
External Knee Adduction Moment

Objective. To investigate the relationship between knee muscle strength and the external knee adduction moment during walking in obese knee osteoarthritis patients and whether disease severity influences this relationship. Methods. This cross-sectional study included 136 elderly obese (BMI>30) adults with predominant medial knee osteoarthritis. Muscle strength, standing radiographic severity as measured by the Kellgren and Lawrence scale, and the peak external knee adduction moment were measured at self-selected walking speed. Results. According to radiographic severity, patients were classified as “less severe” (KL 1-2, N=73) or “severe” (KL 3-4, N=63). A significant positive association was demonstrated between the peak knee adduction moment and hamstring muscle strength in the whole cohort (P=.047). However, disease severity did not influence the relationship between muscle strength and dynamic medial knee joint loading. Severe patients had higher peak knee adduction moment and more varus malalignment (P<.001). Conclusion. Higher hamstring muscle strength relates to higher estimates of dynamic knee joint loading in the medial compartment. No such relationship existed for quadriceps muscle strength. Although cross sectional, the results suggest that hamstrings function should receive increased attention in future studies and treatments that aim at halting disease progression.

scholarly journals Self-Perception of the Knee Is Associated with Joint Motion during the Loading Response in Individuals with Knee Osteoarthritis: A Pilot Cross-Sectional Study

Sensors ◽  
2021 ◽  
Vol 21 (12) ◽  
pp. 4009
Author(s):  
Haruki Toda ◽  
Tsubasa Maruyama ◽  
Koji Fujita ◽  
Yuki Yamauchi ◽  
Mitsunori Tada
Keyword(s):  
Muscle Strength ◽  
Knee Osteoarthritis ◽  
Knee Flexion ◽  
Cross Sectional Study ◽  
Measurement Unit ◽  
Self Perception ◽  
Cross Sectional ◽  
Fast Speed ◽  
Perceptual Impairment ◽  
The Relationship

Small knee flexion motion is a characteristic of gait in individuals with knee osteoarthritis. This study examined the relationship between knee flexion excursion in loading response and knee self-perception in individuals with knee osteoarthritis. Twenty-one individuals with knee osteoarthritis participated in this study. Knee flexion excursions in loading response while walking at a comfortable and a fast-walking speed were measured using an inertial measurement unit-based motion capture system. The degree of knee perceptual impairment was evaluated using the Fremantle Knee Awareness Questionnaire (FreKAQ). The relationships between the FreKAQ score and gait variables and knee function were evaluated by calculating the correlation coefficient. The unique contributions of knee self-perception and muscle strength to knee flexion excursion in loading response were analyzed using hierarchical linear regression. Knee self-perception was significantly correlated with pain during walking, muscle strength and knee flexion excursion at fast speed. In the fast speed condition only, impaired knee self-perception was inversely proportional to knee flexion excursion and accounted for 21.8% of the variance in knee flexion excursion. This result suggests that impaired self-perception of the knee may help to explain the decrease in the knee flexion excursion in the loading response in individuals with knee osteoarthritis.

scholarly journals Self-Reported Walking Difficulty Associated with Stiff-Knee Gait in Japanese Patients with Knee Osteoarthritis: A Preliminary Cross-Sectional Study

Healthcare ◽  
2021 ◽  
Vol 9 (10) ◽  
pp. 1308
Author(s):  
Haruki Toda ◽  
Tsubasa Maruyama ◽  
Koji Fujita ◽  
Yuki Yamauchi ◽  
Mitsunori Tada
Keyword(s):  
Knee Osteoarthritis ◽  
Knee Flexion ◽  
A Priori ◽  
Japanese Patients ◽  
Cross Sectional Study ◽  
Measurement Unit ◽  
Cross Sectional ◽  
Stiff Knee ◽  
Japanese Knee Osteoarthritis Measure ◽  
Walking Difficulty

Background: Individuals with knee osteoarthritis are restricted in their daily activity because of walking difficulty. The purpose of this investigation was to examine the association between self-reported walking difficulty and knee flexion excursion during gait in Japanese patients with knee osteoarthritis. Methods: Twenty-eight patients with knee osteoarthritis participated in this study. Knee flexion excursions in loading response and swing during gait were measured through an inertial measurement unit-based motion capture system. The walking difficulty was assessed by a subitem in the Japanese Knee Osteoarthritis Measure. Pain intensity was assessed by a visual analog scale. Characteristics and gait variables were compared between groups that were determined a priori using the results of the walking difficulty assessment. The relationship between knee flexion excursion during gait and walking difficulty were analyzed using logistic regression. Results: The participants with walking difficulty had significantly small knee flexion excursion in both loading response and swing with large pain. After controlling the effect of pain, only knee flexion excursion in the swing was significantly related to the walking difficulty. Conclusions: This study suggested that the knee flexion excursion in swing during gait is helpful for understanding the walking difficulty experienced in Japanese patients with knee osteoarthritis.

scholarly journals Exercise-induced pain changes associate with changes in muscle perfusion in knee osteoarthritis: exploratory outcome analyses of a randomised controlled trial

2019 ◽  
Vol 20 (1) ◽  
Author(s):  
Elisabeth Bandak ◽  
Mikael Boesen ◽  
Henning Bliddal ◽  
Robert G. C. Riis ◽  
Sabrina Mai Nielsen ◽  
...  
Keyword(s):  
Muscle Strength ◽  
Knee Osteoarthritis ◽  
Exercise Therapy ◽  
Group Differences ◽  
Dce Mri ◽  
Muscle Perfusion ◽  
Knee Oa ◽  
Knee Muscle ◽  
Randomised Controlled ◽  
And Function

Abstract Background Exercise therapy is recommended for knee osteoarthritis (OA), but the underlying mechanisms of pain relief are not fully understood. The purpose of this study was to explore the effects of exercise on muscle perfusion assessed by dynamic contrast enhanced MRI (DCE-MRI) and its association with changes in pain in patients with knee OA. Methods Exploratory outcome analyses of a randomised controlled study with per-protocol analyses (ClinicalTrials.gov: NCT01545258) performed at an outpatient clinic at a public hospital in Denmark. We compared 12 weeks of supervised exercise therapy 3 times per week (ET) with a no attention control group (CG). Analyses of covariance (ANCOVA) were used to assess group mean differences in changes from baseline to week 12 in knee muscle perfusion quantified by DCE-MRI, patient-reported pain and function using the Knee Injury and Osteoarthritis Outcome Score (KOOS) questionnaire, knee extensor and flexor muscle strength tests, and the six-minute walking test (6MWT). Spearman’s correlation coefficients were used to determine the correlation between changes in DCE-MRI variables, KOOS, muscle strength, and 6MWT. The potential effect mediation of the DCE-MRI perfusion variables was investigated in a post-hoc mediation analysis. Results Of 60 participants randomised with knee osteoarthritis, 33 (ET, n = 16, CG, n = 17) adhered to the protocol and had complete DCE-MRI data. At follow-up, there were significant group differences in muscle perfusion changes and clinically relevant group differences in KOOS pain changes (10.7, 95% CI 3.3 to 18.1, P = 0.006) in favor of ET. There were no significant between-group differences on muscle strength and function. The changes in pain and muscle perfusion were significantly correlated (highest Spearman’s rho = 0.42, P = 0.014). The mediation analyses were generally not statistically significant. Conclusion The pain-reducing effects of a 12-week exercise program are associated with changes in knee muscle perfusion quantified by DCE-MRI in individuals with knee OA, but whether the effects are mediated by muscle perfusion changes remains unclear. Trial registration ClinicalTrials.gov: NCT01545258, first posted March 6, 2012.

scholarly journals POS1470-HPR BARRIERS AND FACILITATORS OF A NEW MODEL OF STRATIFIED EXERCISE THERAPY IN KNEE OSTEOARTHRITIS: A QUALITATIVE STUDY

2021 ◽  
Vol 80 (Suppl 1) ◽  
pp. 1020.1-1020
Author(s):  
J. Knoop ◽  
W. Van Berkel-de Joode ◽  
H. Brandt ◽  
J. Dekker ◽  
R. Ostelo
Keyword(s):  
Primary Care ◽  
Randomized Controlled Trial ◽  
Muscle Strength ◽  
Qualitative Study ◽  
Knee Osteoarthritis ◽  
Exercise Therapy ◽  
Controlled Trial ◽  
Barriers And Facilitators ◽  
Added Value ◽  
Randomized Controlled

Background:We have developed a model of stratified exercise therapy, in which three knee osteoarthritis (OA) subgroups (i.e., ‘high muscle strength subgroup’, ‘low muscle strength subgroup’ and ‘obesity subgroup’) can be distinguished and provided a subgroup-specific intervention. Currently, the (cost-)effectiveness of this model compared to usual exercise therapy is tested in a large-scaled randomized controlled trial (OCTOPuS-study [1]). Alongside this trial, we performed a qualitative study to explore perceived barriers and facilitators of the application of this model in primary care.Objectives:To explore barriers and facilitators of the application of this model in primary care, as perceived by patients, physiotherapists and dieticians.Methods:Qualitative data were collected through semi-structured interviews in a random sample of 15 patients (5 from each subgroup), 11 physiotherapists and 5 dieticians, from the experimental arm of the OCTUPuS trial. A thematic analysis of the data was performed.Results:We identified 14 themes in 5 categories. In general, patients and therapists were positive about the added value and applicability of the model, although some physiotherapists would prefer more flexibility. Regarding the ‘high muscle strength subgroup’, both patients and physiotherapists reported mixed feelings on the low number of supervised sessions, with some perceiving this low number as advantageous for stimulating the patient’s own responsibility, whereas others as hindering an optimally guided treatment. Regarding the ‘obesity subgroup’, dieticians and physiotherapists acknowledged the added value of the combined intervention, but both were disappointed by the lack of interdisciplinary collaboration. Moreover, those patients in this subgroup already following a diet restriction, therefore not perceiving any added value of the diet intervention.Conclusion:This qualitative study revealed relevant barriers and facilitators of our new model of stratified exercise therapy, which will help us interpreting the upcoming results on its (cost-) effectiveness [1]. If proven to be (cost-)effective, implementation strategies should specifically focus on guidance of patients from the ‘high muscle strength subgroup’ within only a few sessions, collaboration between physiotherapist and dietician in the ‘obesity subgroup’, and adequate use of booster sessions after the supervised period to optimize treatment adherence.References:[1]Knoop J, Dekker J, van der Leeden M, de Rooij M, Peter WFH, van Bodegom-Vos L, van Dongen JM, Lopuhäa N, Bennell KL, Lems WF, van der Esch M, Vliet Vlieland TPM, Ostelo RWJG. Stratified exercise therapy compared with usual care by physical therapists in patients with knee osteoarthritis: A randomized controlled trial protocol (OCTOPuS study). Physiother Res Int. 2020 Apr;25(2):e1819. doi: 10.1002/pri.1819. Epub 2019 Nov 28.Disclosure of Interests:None declared

The Association Between Serum 25-hydroxy Vitamin D Level and Upper Leg Strength in Patients with Knee Osteoarthritis: Results of the Amsterdam Osteoarthritis Cohort

2016 ◽  
Vol 43 (7) ◽  
pp. 1400-1405 ◽  
Author(s):  
Esmee Koeckhoven ◽  
Marike van der Leeden ◽  
Leo D. Roorda ◽  
Natasja M. van Schoor ◽  
Paul Lips ◽  
...  
Keyword(s):  
Vitamin D ◽  
Muscle Strength ◽  
Knee Osteoarthritis ◽  
Muscle Weakness ◽  
Cross Sectional Study ◽  
Blood Collection ◽  
Cross Sectional ◽  
Knee Oa ◽  
Leg Strength ◽  
25 Hydroxy Vitamin D

Objective.Vitamin D deficiency, which is common among elderly people, has been linked to muscle weakness. In patients with knee osteoarthritis (OA), the association between muscle strength and serum 25-hydroxy Vitamin D [25(OH)D] level has not been studied comprehensively. The aim of our study was to examine the association between serum 25(OH)D level and muscle strength in patients with knee OA.Methods.Data of the Amsterdam Osteoarthritis cohort from 319 participants with knee OA were used in a cross-sectional study. Serum 25(OH)D level (nmol/l) was measured by a competitive electrochemiluminescence method. Muscle strength (nm/kg) of the upper leg was measured isokinetically. Univariable and multivariable linear regression analyses were used to calculate the association between serum 25(OH)D level and muscle strength.Results.Serum 25(OH)D level was significantly associated with muscle strength (B = 0.036, 95% CI 0.017–0.054, p < 0.001), adjusted for season of blood collection. After adding body mass index (BMI) to the model, this association was no longer significant (B = 0.011, 95% CI −0.007 to 0.029, p = 0.214). Alcohol consumption, number of comorbidities, and sex were subsequently added and changed the model slightly. Without BMI, this model showed a significant association between serum 25(OH)D level and muscle strength (B = 0.029, 95% CI 0.014–0.043, p < 0.001).Conclusion.The observed association between a low serum 25(OH)D level and muscle weakness in patients with knee OA is attenuated by BMI. Further studies are needed to explain the associations among Vitamin D level, muscle strength, and adiposity in patients with knee OA.

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