Identification of clinical phenotypes in knee osteoarthritis: a systematic review of the literature

Background: Knee Osteoarthritis (KOA) is a heterogeneous pathology characterized by a complex and multifactorial nature. It has been hypothesised that these differences are due to the existence of underlying phenotypes representing different mechanisms of the disease.Methods: The aim of this study is to identify the current evidence for the existence of groups of variables which point towards the existence of distinct clinical phenotypes in the KOA population. A systematic literature search in PubMed was conducted. Only original articles were selected if they aimed to identify phenotypes of patients aged 18 years or older with KOA. The methodological quality of the studies was independently assessed by two reviewers and qualitative synthesis of the evidence was performed. Strong evidence for existence of specific phenotypes was considered present if the phenotype was supported by at least two high-quality studies.Results: A total of 24 studies were included. Through qualitative synthesis of evidence, six main sets of variables proposing the existence of six phenotypes were identified: 1) chronic pain in which central mechanisms (e.g. central sensitisation) are prominent; 2) inflammatory (high levels of inflammatory biomarkers); 3) metabolic syndrome (high prevalence of obesity, diabetes and other metabolic disturbances); 4) Bone and cartilage metabolism (alteration in local tissue metabolism); 5) mechanical overload characterised primarily by varus malalignment and medial compartment disease; and 6) minimal joint disease characterised as minor clinical symptoms with slow progression over time.Conclusions: This study identified six distinct groups of variables which should be explored in attempts to better define clinical phenotypes in the KOA population

The challenges of measuring physical activity and sedentary behaviour in people with rheumatoid arthritis

The importance of sufficient moderate-to-vigorous physical activity as a key component of a healthy lifestyle is well established, as are the health risks associated with high levels of sedentary behaviour. However, many people with RA do not undertake sufficient physical activity and are highly sedentary. To start addressing this, it is important to be able to carry out an adequate assessment of the physical activity levels of individual people in order that adequate steps can be taken to promote and improve healthy lifestyles. Different methods are available to measure different aspects of physical activity in different settings. In controlled laboratory environments, respiratory gas analysis can measure the energy expenditure of different activities accurately. In free-living environments, the doubly labelled water method is the gold standard for identifying total energy expenditure over a prolonged period of time (>10 days). To assess patterns of physical activity and sedentary behaviour in daily life, objective methods with body-worn activity monitors using accelerometry are superior to self-reported questionnaire- or diary-based methods

A protocol for a randomised controlled trial of prefabricated versus customised foot orthoses for people with rheumatoid arthritis: the FOCOS RA trial [Foot Orthoses – Customised v Off-the-Shelf in Rheumatoid Arthritis]

Abstract Background Foot pain is common in rheumatoid arthritis and appears to persist despite modern day medical management. Several clinical practice guidelines currently recommend the use of foot orthoses for the treatment of foot pain in people with rheumatoid arthritis. However, an evidence gap currently exists concerning the comparative clinical- and cost-effectiveness of prefabricated and customised foot orthoses in people with early rheumatoid arthritis. Early intervention with orthotics may offer the best opportunity for positive therapeutic outcomes. The primary aim of this study is to evaluate the comparative clinical- and cost-effectiveness of prefabricated versus customised orthoses for reducing foot pain over 12 months. Methods/design This is a multi-centre two-arm parallel randomised controlled trial comparing prefabricated versus customised orthoses in participants with early rheumatoid arthritis (< 2 years disease duration). A total of 160 (a minimum of 80 randomised to each arm) eligible participants will be recruited from United Kingdom National Health Service Rheumatology Outpatient Clinics. The primary outcome will be foot pain measured via the Foot Function Index pain subscale at 12 months. Secondary outcomes will include foot related impairments and disability via the Foot Impact Scale for rheumatoid arthritis, global functional status via the Stanford Health Assessment Questionnaire, foot disease activity via the Rheumatoid Arthritis Foot Disease Activity Index, and health-related quality of life at baseline, 6 and 12 months. Process outcomes will include recruitment/retention rates, data completion rates, intervention adherence rates, and participant intervention and trial participation satisfaction. Cost-utility and cost-effectiveness analyses will be undertaken. Discussion Outcome measures collected at baseline, 6 and 12 months will be used to evaluate the comparative clinical- and cost- effectiveness of customised versus prefabricated orthoses for this treatment of early rheumatoid arthritis foot conditions. This trial will help to guide orthotic prescription recommendations for the management of foot pain for people with early rheumatoid arthritis in future. Trial registration ISRCTN13654421. Registered 09 February 2016

Impact of exercise on articular cartilage in people at risk of, or with established, knee osteoarthritis: a systematic review of randomised controlled trials

This project is supported by a European Union Seventh Framework Programme (FP7-PEOPLE-2013-ITN; KNEEMO) under grant agreement number 607510.Peer reviewedPostprin

The role of perceived organisational justice in the experience of pain among male and female employees

This study examined the association of organisational justice with pain among employees of a large organisation. Employees (n = 1829) completed measures of pain, fair pay, organisational justice, job satisfaction and stress. Logistic regression analyses found that organisational justice was unrelated to pain among women, but men with higher perceptions of fair pay were more likely to report chronic pain as were men with lower perceptions of distributive justice. This is the first study indicating that fair pay and distributive justice are both unique predictors of chronic pain in men. The findings have implications for supporting employees with chronic pain

Biomechanical factors associated with the development of tibiofemoral knee osteoarthritis: protocol for a systematic review and meta-analysis

INTRODUCTION: Altered biomechanics, increased joint loading and tissue damage, might be related in a vicious cycle within the development of knee osteoarthritis (KOA). We have defined biomechanical factors as joint-related factors that interact with the forces, moments and kinematics in and around a synovial joint. Although a number of studies and systematic reviews have been performed to assess the association of various factors with the development of KOA, a comprehensive overview focusing on biomechanical factors that are associated with the development of KOA is not available. The aim of this review is (1) to identify biomechanical factors that are associated with (the development of) KOA and (2) to identify the impact of other relevant risk factors on this association. METHODS AND ANALYSIS: Cohort, cross-sectional and case–control studies investigating the association of a biomechanical factor with (the development of) KOA will be included. MEDLINE, EMBASE, CINAHL and SPORTDiscus will be searched from their inception until August 2015. 2 reviewers will independently screen articles obtained by the search for eligibility, extract data and score risk of bias. Quality of evidence will be evaluated. Meta-analysis using random effects model will be applied in each of the biomechanical factors, if possible. ETHICS AND DISSEMINATION: This systematic review and meta-analysis does not require ethical approval. The results of this systematic review and meta-analysis will be disseminated through publications in peer-reviewed journals and presentations at (inter)national conferences. TRIAL REGISTRATION NUMBER: CRD42015025092

Ultrasound features of achilles enthesitis in psoriatic arthritis: a systematic review

OBJECTIVES: The objectives were to evaluate the methodological and reporting quality of ultrasound (US) studies of Achilles enthesitis in people with psoriatic arthritis (PsA), to identify the definitions and scoring systems adopted and to estimate the prevalence of ultrasound features of Achilles enthesitis in this population. METHODS: A systematic literature review was conducted using the AMED, CINAHL, MEDLINE, ProQuest and Web of Science databases. Eligible studies had to measure US features of Achilles enthesitis in people with PsA. Methodological quality was assessed using a modified Downs and Black Quality Index tool. US protocol reporting was assessed using a checklist informed by the European League Against Rheumatism (EULAR) recommendations for the reporting of US studies in rheumatic and musculoskeletal diseases. RESULTS: Fifteen studies were included. One study was scored as high methodological quality, 9 as moderate and 5 as low. Significant heterogeneity was observed in the prevalence, descriptions, scoring of features and quality of US protocol reporting. Prevalence estimates (% of entheses) reported included hypoechogenicity [mean 5.9% (s.d. 0.9)], increased thickness [mean 22.1% (s.d. 12.2)], erosions [mean 3.3% (s.d. 2.5)], calcifications [mean 42.6% (s.d. 15.6)], enthesophytes [mean 41.3% (s.d. 15.6)] and Doppler signal [mean 11.8% (s.d. 10.1)]. CONCLUSIONS: The review highlighted significant variations in prevalence figures that could potentially be explained by the range of definitions and scoring criteria available, but also due to the inconsistent reporting of US protocols. Uptake of the EULAR recommendations and using the latest definitions and validated scoring criteria would allow for a better understanding of the frequency and severity of individual features of pathology

Knee Internal Contact Force in a Varus Malaligned Phenotype in Knee Osteoarthritis

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155?Sex-related differences in muscle co-activation in individuals with knee osteoarthritis

Background: Sex-related differences in muscle function have been well established in healthy individuals. In individuals with knee osteoarthritis (KOA), impairments in muscle function such as muscle weakness and high muscle co-activation have also been demonstrated. Muscle dysfunction has been shown to be a strong contributor to poor physical function and low health-related quality of life in patients with KOA. The purpose of this study was, therefore, to analyse sex and osteoarthritis-related differences in muscle function, to establish to what extent both sex and disease status contribute to muscle dysfunction.Methods: Muscle co-activation was assessed in 77 symptomatic KOA participants (62.5±8.1yrs; 48/29 women/men) and 18 age-matched asymptomatic controls (62.5±10.4yrs; 9/9 women/men), using electromyography (EMG) during a series of walking, stair ascent and descent and sit-to-walk activities. EMG was recorded from 7 sites medial/lateral gastrocnemius, biceps femoris, semitendinosus, vastus lateralis/medialis and normalised to maximal voluntary contraction. Normalised EMG was used to calculate hamstrings-quadriceps and medial-lateral muscle co-activation as (antagonist/agonist) *(antagonist+agonist). The stance phase of walking was split into pre-stance (150ms prior to initial contact), loading (0-15% of stance), early-stance (15-40%), mid-stance (40-60%), late-stance (60-100%) and overall-stance (0-100%). Stairs negotiation was also split into transition (stance phase on the floor) and continuous (stance phase on the second step of the staircase). All participants provided written informed consent and the study was approved by Research Ethics committees (HLS12/86, 13/ws/0146). Independent samples T-tests were performed to assess the differences between KOA and controls. Linear regressions were performed to investigate the relationship between muscle function, sex and disease status, and Bonferroni corrected for multiple comparisons.Results: Individuals with KOA were weaker than controls (P < 0.007). Overall there were very few differences in muscle co-activation between KOA and controls. Women were weaker than men (P ⩽ 0.002) and had higher hamstrings-quadriceps and medial-lateral muscle co-activation across all activities of daily living. In multiple regression analyses sex and muscle weakness, but not age or disease status, predicted high muscle co-activation.Conclusion: High muscle co-activation was associated with female sex and muscle weakness regardless of disease status and age. It has previously been suggested that muscle co-activation acts as a compensatory mechanism for muscle weakness, accommodating for the diminished force generating capabilities to maintain a certain level of function and movement activation patterns. This suggests that muscle weakness may be the main contributing factor for high muscle co-activation which is thought to increase joint loads with detrimental effects on cartilage and joint integrity. This may explain high muscle co-activation in women with muscle weakness and increased risk of incidence and progression of KOA in women