Characterizing Pain Flares From the Perspective of Individuals With Symptomatic Knee Osteoarthritis

Temporal Associations of Physical Activity With Subsequent Knee Pain in Individuals With Knee Osteoarthritis: An Ecological Momentary Assessment Study

BACKGROUND

Physical activity (PA) is a first-line treatment for knee osteoarthritis and provides benefits for functional improvement and pain relief. However, movement-evoked pain often hinders PA participation and long-term adherence. The relationship between PA and pain is not fully understood and may vary across individuals. We examined the temporal associations between PA and subsequent knee pain in individuals with knee osteoarthritis.

METHODS

In a 10-day ecological momentary assessment (EMA) cohort study, PA was recorded using an Actigraph accelerometer; momentary knee pain intensity was rated on a numeric rating scale in responses to four daily text prompts. Linear mixed-effects models examined within-day and between-day associations between PA and knee pain, adjusting for age, sex and BMI.

RESULTS

The sample included up to 454 observations across 10 days from 17 participants (age = 64 ± 7 years, BMI = 27 ± 4 kg/m2, 61% women), each consisting of a temporal pair of PA minutes and subsequent momentary pain. Within-day, greater moderate-to-vigorous PA (MVPA) minutes were associated with a subsequent increase in knee pain (adjusted β = 0.112, 95% CI: 0.023, 0.201, p = 0.014); while light-intensity PA showed no association with subsequent pain (adjusted β = -0.003, 95% CI: -0.011, 0.005, p = 0.461). Current-day MVPA and light-intensity PA minutes were not associated with next-day knee pain.

CONCLUSIONS

While MVPA may temporarily increase knee pain, its impact was transient. Light-intensity PA showed no association with pain, suggesting it may be a suitable alternative for those with movement-evoked pain. Understanding these temporal patterns can help guide tailored pain management and PA adherence strategies. Further research is needed to confirm these preliminary findings.

SIGNIFICANCE STATEMENT

Understanding the dynamic relationship between PA and knee pain is crucial for optimising the management of knee OA. This exploratory study offers new insights by leveraging high-frequency data to examine the intra- and inter-day associations of MVPA and light-intensity PA with subsequent knee pain. The preliminary findings demonstrate that MVPA may lead to transient pain increases, while light-intensity PA is not associated with pain intensity. Identifying these PA-pain temporal patterns can inform personalised strategies for pain management and improving long-term activity adherence.

Clinical Assessment of Osteoarthritis Pain: Contemporary Scenario, Challenges, and Future Perspectives

The multifaceted nature of osteoarthritis (OA) pain presents a challenge in understanding and managing the condition. The diverse pain experiences, progression rates, individual responses to treatments, and complex disease mechanisms contribute to heterogeneity in the clinical studies outcomes. The lack of a standardized methodology for assessing and classifying OA pain challenges healthcare practitioners. This complicates the establishment of universally applicable protocols or standardized guidelines for treatment. This article explores the heterogeneity observed in clinical studies evaluating OA pain treatments, highlighting the necessity for refined methodologies, personalized patient categorization, and consistent outcome measures. It discusses the role of the multidimensional nature of OA pain, underlying pain mechanisms, and other contributing factors to the heterogeneity in outcome measures. Addressing these variations is crucial to establishing a more consistent framework for evidence-based treatments and advancing care of the patient with OA pain.

A scoping review of patient self-report measures of flare in knee and hip osteoarthritis (OA): A report from the OMERACT flares in OA working group

PURPOSE

We aimed to analyze the content validity/domain match and feasibility of self-report instruments that could measure flare in osteoarthritis (OA), by extending our 2017 literature review on the definition of flare in knee and hip OA.

METHOD

We searched PubMed (Medline), Web of Science and PsycInfo (Ebsco Host) databases for original articles reporting research about flare (or synonyms) in humans with knee and hip OA, between 2017 and 2023. Four experts worked independently, checking the records, and assessing content validity and feasibility, writing justification for exclusion.

RESULTS

At literature review phase, 575 papers were filtered. After experts' analysis, 59 studies were included, and 44 instruments associated with flare in OA were identified. Most were studies about pain in knee or hip OA (35 %), cultural adaptation of a measure (33 %) or studies investigating psychometric properties of full (16 %) or short form (4 %) instruments. The assessment of domain match and feasibility revealed that 15 instruments were assigned a label of 'yes' or 'uncertain' as to whether or not there was a good match with the domain concept or whether the instrument was considered feasible to use.

DISCUSSION

Most identified instruments considered different aspects of pain and the associated discomfort in performing daily activities but did not include the central aspects of flare in OA, i.e. the change of state, nor the additional Outcome Measures in Rheumatology (OMERACT) endorsed domains for OA flare namely stiffness, swelling, psychological aspects, impact of symptoms including fatigue and sleep disturbance. Although it is possible that the period specified to conduct this literature review may have led to some recognized instruments being excluded, this review demonstrates the need for the research community to reach consensus on the best way to measure self-reported flares in future clinical trials and observational studies.

Mapping the neuroethological signatures of pain, analgesia, and recovery in mice

Ongoing pain is driven by the activation and modulation of pain-sensing neurons, affecting physiology, motor function, and motivation to engage in certain behaviors. The complexity of the pain state has evaded a comprehensive definition, especially in non-verbal animals. Here, in mice, we used site-specific electrophysiology to define key time points corresponding to peripheral sensitivity in acute paw inflammation and chronic knee pain models. Using supervised and unsupervised machine learning tools, we uncovered sensory-evoked coping postures unique to each model. Through 3D pose analytics, we identified movement sequences that robustly represent different pain states and found that commonly used analgesics do not return an animal's behavior to a pre-injury state. Instead, these analgesics induce a novel set of spontaneous behaviors that are maintained even after resolution of evoked pain behaviors. Together, these findings reveal previously unidentified neuroethological signatures of pain and analgesia at heightened pain states and during recovery.

Assessment of Pain in Osteoarthritis of the Knee

Knee osteoarthritis (KOA) pain is a subjective and personal experience, making it challenging to characterise patients' experiences and assess their pain. In addition, there is no global standard for the assessment of pain in KOA. Therefore, this article examines the possible methods of assessing and characterising pain in patients with KOA using clinical symptoms, pain assessment tools, and imaging. We examine the current methods of assessment of pain in KOA and their application in clinical practice and clinical trials. Furthermore, we explore the possibility of creating individualised pain management plans to focus on different pain characteristics. With better evaluation and standardisation of pain assessment in these patients, it is hoped that patients would benefit from improved quality of life. At the same time, improvement in pain assessment would enable better data collection regarding symptom response in clinical trials for the treatment of osteoarthritis.

Three Weekly Intra-Articular Injections of Hylan G-F 20 vs Arthrocentesis in Patients with Chronic Idiopathic Knee Osteoarthritis: A Multicenter, Evaluator- and Patient-Blinded, Randomized Controlled Trial

Background

Knee osteoarthritis is a leading cause of disability worldwide. Symptoms can vary over time, leading to episodes of worsened symptoms known as flares. Intra-articular injection of hyaluronic acid has demonstrated long-term symptomatic relief in the broader knee osteoarthritis population, although its use in the flare population has not been extensively examined.

Objective

To assess the efficacy and safety of 3 once-weekly intra-articular injections of hylan G-F 20 (as single and repeat courses) in patients with chronic knee osteoarthritis, including a subpopulation that experienced flare.

Methods

Prospective randomized controlled, evaluator- and patient-blinded, multicenter trial with 2 phases: hylan G-F 20 vs arthrocentesis only (control) and 2 courses vs single-course hylan G-F 20. Primary outcomes were visual analog scale (0-100 mm) pain scores. Secondary outcomes included safety and synovial fluid analysis.

Results

Ninety-four patients (104 knees) were enrolled in Phase I, with 31 knees representing flare patients. Seventy-six patients (82 knees) were enrolled in Phase II. Long-term follow-up was 26 to 34 weeks. In flare patients, hylan G-F 20 showed significantly more improvement than the controls for all primary outcomes except pain at night (P = 0.063). Both 1 and 2 courses of hylan G-F 20 showed significant improvements from baseline for primary outcomes with no differences in efficacy between groups in the intention-to-treat population at the end of Phase II. Two courses of hylan G-F 20 showed better improvement in pain with motion (P = 0.0471) at long-term follow-up. No general side effects were reported, and local reactions (pain/swelling of the injected joint) resolved within 1 to 2 weeks. Hylan G-F 20 was also associated with reduced effusion volume and protein concentration.

Conclusions

Hylan G-F 20 significantly improves pain scores vs arthrocentesis in flare patients with no safety concerns. A repeat course of hylan G-F 20 was found to be well tolerated and efficacious.

Clinical aspects and outcomes in osteoarthritis

Osteoarthritis (OA) is the most prevalent type of arthritis worldwide, and its incidence significantly increases with age. It commonly affects the knees, hips, spine, big toes, and hands. OA can be identified through clinical examination, symptoms, and imaging methods. Its main symptoms include pain, stiffness, and limitations in joint movement. Examinations may reveal coarse crepitus, bony enlargement, and tenderness at the joint line. In severe cases of OA, rest pain, night pain, and deformity may occur. OA can lead to decreased physical activity, function, and quality of life due to symptoms such as pain and stiffness. To evaluate these impacts, patient-reported outcome measures (PROMs) are necessary. Various generic, disease-specific, and joint-specific PROMs have been developed and used in clinical practice to assess the outcomes of OA.

Osteoarthritis Flares

The phenomenon of flares is a common feature in the daily life of people with osteoarthritis (OA). Characterized by episodes of sudden-onset increases in signs and symptoms, their impact can often be distressing and disabling. Despite their potential to have both short-term and long-term consequences for patients across the whole course of the condition, their occurrence and optimal management are not fully understood. This article provides a contemporary perspective on defining OA flares and their potential triggers, and offers suggestions for how health professionals might explore flare patterns with patients in clinical practice and frame timely best-practice treatment approaches.

Development and validation of the Flare-OA questionnaire for measuring flare in knee and hip osteoarthritis

OBJECTIVE

Ability to assess flares in osteoarthritis (OA) of the knee and hip (KHOA) is important in clinical care and research. Using mixed methods, we developed a self-reported instrument measuring flare and assessed its psychometric properties.

METHODS

We constructed questionnaire items from semi-structured interviews and a focus group (patients, clinicians) by using a dual-language (English-French) approach. A Delphi consensus method was used to select the most relevant items. Patients with OA from Australia, France and the United States completed the preliminary Flare-OA, HOOS, KOOS and Mini-OAKHQOL questionnaires online. We used a factor analysis and content approach to reduce items and determine structural validity. We tested the resulting questionnaire (score 0-100) for internal consistency, convergent and known-groups validity.

RESULTS

Initially, 180 statements were generated and reduced to 33 items in five domains (response 0 = not at all, to 10 = absolutely) by Delphi consensus (50 patients, 116 professionals) and an expert meeting. After 398 patients (mean [SD] age 64 [8.5] years, 70.4% female, 86.7% knee OA) completed the questionnaire, it was reduced to 19 items by factor analysis and a content approach (RMSEA = 0.06; CFI = 0.96; TLI = 0.94). The Cronbach's alpha was >0.9 for the five domains and the whole questionnaire. Correlation coefficients between Flare-OA and other instrument scores were as predicted, supporting construct validity. The difference in Flare-OA score between patients with and without flare (31.8) largely exceeded 2 SEM (10.2).

CONCLUSION

Flare-OA is a valid and reliable patient-reported instrument for assessing the occurrence and severity of flare in patients with KHOA in clinical research.

Pain descriptors and determinants of pain sensitivity in knee osteoarthritis: a community-based cross-sectional study

Objectives

To explore pain characteristics in individuals with knee osteoarthritis (KOA), to compare pain sensitivity across individuals with KOA, chronic back pain (CBP) and pain-free individuals (NP), and to examine the relationship between clinical and pain characteristics with pain sensitivity in KOA.

Methods

Cross-sectional, community-based online survey. Two datasets were combined comprising Dutch individuals of ≥ 40 years of age, experiencing chronic knee pain (KOA, N = 445), chronic back pain (CBP, N = 504), or no pain (NP, N = 256). Demographic and clinical characteristics, global health, physical activity/exercise, and pain characteristics including intensity, spreading, duration, quality (SF-MPQ), and sensitivity (PSQ) were assessed. Differences between (sub)groups were examined using analyses of variance or Chi-square tests. Regression analyses were performed to examine determinants of pain sensitivity in the KOA group.

Results

Quality of pain was most commonly described as aching, tender, and tiring-exhausting. Overall, the KOA group had higher levels of pain sensitivity compared to NP group, but lower levels than the CBP group. Univariately, pain intensity, its variability and spreading, global health, exercise, and having comorbidities were weakly related to pain sensitivity (standardized betas: 0.12-0.27). Symptom duration was not related to pain sensitivity. Older age, higher levels of continuous pain, lower levels of global health, and exercise uniquely contributed, albeit modest, to pain sensitivity (P<0.05).

Conclusion

Continuous pain such as aching and tenderness in combination with decreased physical activity may be indicative for a subgroup of individuals at risk for pain sensitivity and, ultimately, poor treatment outcomes.

How do people with knee osteoarthritis perceive and manage flares? A qualitative study

Background

Acute flares in people with osteoarthritis (OA) are poorly understood. There is uncertainty around the nature of flares, their impact, and how these are managed.

Aim

To explore understandings and experiences of flares in people with knee OA, and to describe self-management and help-seeking strategies.

Design & setting

Qualitative interview study of people with knee OA in England.

Method

Semi-structured interviews were undertaken with 15 people with knee OA. Thematic analysis was applied using constant comparison methods.

Results

The following four main themes were identified: experiencing pain; consequences of acute pain; predicting and avoiding acute pain; and response to acute pain. People with OA described minor episodes that were frequent, fleeting, occurred during everyday activity, had minimal impact, and were generally predictable. This contrasted with severe episodes that were infrequent, had greater impact, and were less likely to be predictable. The latter generally led to feelings of low confidence, vulnerability, and of being a burden. The term ‘flare’ was often used to describe the severe events but this was applied inconsistently and some would describe a flare as any increase in pain. Participants used numerous self-management strategies but tended to seek help when these had been exhausted, their symptoms led to emotional distress, disturbed sleep, or pain experience worse than usual. Previous experiences shaped whether people sought help and who they sought help from.

Conclusion

Severe episodes of pain are likely to be synonymous with flares. Developing a common language about flares will allow a shared understanding of these events, early identification, and appropriate management.

A novel mice model of acute flares in osteoarthritis elicited by intra-articular injection of cultured mast cells

PURPOSE

Mast cells are multifunctional in osteoarthritis (OA), and infiltration of activated mast cells likely contributes to disease severity and progression. However, the detailed mechanisms of action are unclear. The purpose of this study was to elucidate the role of mast cell infiltration in OA at histological level using a new mice model and to investigate pharmacological inhibitory effects of existing mast cell stabilizers in this model.

METHODS

Mice were injected intra-articularly with monosodium iodoacetate (MIA 0.5 mg) or PBS on day 0, and PBS, with or without mast cells (MC: 1 × 10⁶ cells) on day 14. They were divided into four groups: OA flare (MIA + MC), OA (MIA + PBS), MC non-OA (PBS + MC), and PBS non-OA (PBS + PBS). In OA flare, the MC stabilizer drug (tranilast: 400 mg/kg/day) or PBS was administered intraperitoneally from days 15 to 21.

RESULTS

Histologically, modified Mankin score of the OA flare was significantly higher than that of OA (7.0 [1.8] vs. 3.3 [1.3], P < 0.05), and a larger number of mast cells was observed in OA flare than in OA (34.5 [6.3]/mm² vs. 27.2 [2.3]/mm², P < 0.05) on day 22. OA flare also showed acute exacerbation of pain and increased gene expression of pro-inflammatory cytokines and aggrecanase compared with OA. Administration of tranilast to OA flare-up provoked significant improvements in term of histological changes, pain, and gene expression at day 22.

CONCLUSION

Our novel model possibly mimics OA flare conditions, which may open a new strategy of disease-modifying treatment for OA, focused on controlling the multiple functions of mast cells.

Best-practice clinical management of flares in people with osteoarthritis: A scoping review of behavioral, lifestyle and adjunctive treatments

INTRODUCTION

Transient episodes of increased pain, stiffness or swelling are common in people with osteoarthritis (OA). Yet, evidence-based management strategies for lessening the impact of OA flares are rarely covered in clinical guidelines and have been identified as a gap by clinicians delivering OA care. We aimed to identify evidence on behavioral, lifestyle or other adjunctive flare management strategies that could be used by clinicians or consumers.

MATERIALS AND METHODS

A literature search between 1990-2020 was performed in three databases using a scoping methodology. We included qualitative or quantitative studies, and reviews that examined OA flare management, or that reported OA flare outcomes at timepoints ≤2 weeks post-intervention. Outcomes included any physical or psychological OA outcome treatable with a therapeutic intervention.

RESULTS

We included 9 studies, all of which examined the relationship between therapeutic exercise/ physical activity and OA flares. All studies reported pain outcomes at the knee. Two also included the hip. Only two studies examined specific management strategies for OA flares. Both favorably reported the benefits of undertaking an exercise program modified accordingly during an episode, but the quality of the evidence was low.

DISCUSSION

This scoping review highlights the paucity of evidence available on non-pharmacological treatments of OA flare management that could influence clinical practice. At present, there is no robust evidence to support or reject any specific therapies for OA flare management in clinical practice. Future work is needed, particularly around outcomes beyond pain, trajectories of symptom improvement, and for joints other than the knee.

Recent Injury, Severe Radiographic Change, and Lower Quadriceps Strength Increase Risk of Knee Pain Exacerbation During Walking: A Within-Person Knee-Matched Study

OBJECTIVE

To examine the associations of knee injury, radiographic osteoarthritis severity, and quadriceps strength with knee pain exacerbation during walking.

DESIGN

Within-person knee-matched case-control study.

METHODS

Participants from the Osteoarthritis Initiative who completed a 20-m walking test at the 24-month visit were included. Pain exacerbation was defined as an increase in pain intensity of 1 or more on a numeric rating scale (0 as no pain and 10 as the worst imaginable pain) while completing the 20-m walking test. We used conditional logistic regression to assess the relation of recent knee injury, Kellgren-Lawrence (KL) grade, and quadriceps strength to unilateral knee pain exacerbation during walking.

RESULTS

We included 277 people who experienced unilateral knee pain exacerbation during the walking test. Recent knee injury was associated with pain exacerbation during walking, with an odds ratio of 3.4 (95% confidence interval [CI]: 1.3, 9.2). Compared with knees with a KL grade of 0, the odds ratios of pain exacerbation during walking were 1.3 (95% CI: 0.7, 2.7), 3.3 (95% CI: 1.5, 7.1), and 8.1 (95% CI: 3.1, 21.1) for knees with KL grades of 2, 3, and 4, respectively. Painful knees with a deficit in quadriceps strength of greater than or equal to 4% had a 1.4-fold (95% CI: 1.0, 1.9) higher risk of pain exacerbation during walking than their pain-free counterparts.

CONCLUSION

Recent knee injury, more severe radiographic osteoarthritis, and lower quadriceps strength were associated with an increased risk of knee pain exacerbation during walking. J Orthop Sports Phys Ther 2021;51(6):298-304. Epub 10 May 2021. doi:10.2519/jospt.2021.9735.

Can pain flares in knee osteoarthritis be predicted?

Objectives: This study examined whether risk factors for knee osteoarthritis (KOA) pain such as age, gender, body mass index (BMI), baseline pain, and other putative risk factors for knee osteoarthritis pain flares (KOAF) (e.g. knee buckling, injury, mood/stress/social support scores, and footwear) could predict KOAF.Method: People with KOA and previous history of KOAF were selected from a 3 month web-based longitudinal study. KOAF was defined as an increase of ≥ 2 points on a numeric rating scale (compared with background pain) which resolved within 20 days. Predictors assessed at baseline were gender, age, duration of KOA, BMI, pain, knee injury (7 days before), knee buckling (2 days before), Lubben Social Support, Knee Injury and Osteoarthritis Outcome Score, Intermittent and Constant Osteoarthritis Pain score (ICOAP), Positive/Negative Affect Score, and footwear stability/heel height. Outcome was occurrence of any KOAF during the ensuing 30 days. The combined ability of the above variables to predict occurrence of any KOAF was evaluated by multiple logistic regression with a 10-fold cross-validation method to build and internally validate the model. Variables that assessed similar domains were eliminated using receiver operating characteristics curve assessment for best fit.Results: Complete data were available for 313 people (66.6% female, mean ± sd age 62.3 ± 8.2 years, BMI 29.7 ± 6.5 kg/m²). Increasing age, years of osteoarthritis, BMI, background/worst levels of pain, knee injury, knee buckling, ICOAP, and footwear category/heel height significantly predicted the occurrence of KOAF during the following 30 days, with an area under the curve of 0.73 (95% confidence interval 0.67-0.80).Conclusion: A combination of risk factors assessed at baseline, including exposures with potential to vary, successfully predicts the KOAF in the ensuing 30 days.

Pain characteristics and biomarkers in treatment approaches for osteoarthritis pain

Osteoarthritis (OA) is a progressive disease and OA pain intensity is related to ongoing pathophysiological changes. However, OA pain is complex and multimodal; its characteristics, including severity, localization and the stimuli that elicit it, can change as the disease progresses and differ greatly among patients. Understanding mechanisms underlying specific pain characteristics may help guide clinicians in choosing appropriate treatments, targeting treatments to those patients most likely to benefit. Associations have been demonstrated between biomarkers and some characteristics of OA pain, and to processes linked to the shift in pain characteristics over the course of OA. This article examines how understanding OA pain characteristics and their relation to the disease process could inform treatment choice when applying well-established treatment guidelines.

Is There a Relationship Between Kinesiophobia and Physical Activity Level in Patients with Knee Osteoarthritis?

OBJECTIVE

To investigate the levels of kinesiophobia, physical activity, depression, disability, and quality of life in patients with knee osteoarthritis.

DESIGN

A cross-sectional study.

SETTING

A tertiary health care center.

SUBJECTS

Ninety-six patients with knee osteoarthritis.

METHODS

Pain intensity was evaluated by the Visual Analog Scale, kinesiophobia by the Tampa Scale of Kinesiophobia and Brief Fear of Movement Scale, depression by the Beck Depression Inventory, disability by the Western Ontario and McMaster Universities Arthritis Index, physical activity level by the International Physical Activity Questionnaire short form, and quality of life by the Short Form 12 Health Survey Questionnaire.

RESULTS

Of the patients, 85.7% had high-level kinesiophobia, 70.6% had depression, and 64.4% had low, 27.8% moderate, and 7.8% high physical activity levels. Age, activity-related pain score of the Visual Analog Scale, Tampa Scale of Kinesiophobia and Brief Fear of Movement Scale scores, and Western Ontario and McMaster Universities Arthritis Index and Beck Depression Inventory scores were higher in the group with high-level kinesiophobia, whereas the mental, physical, and total scores obtained from the Short Form 12 Health Survey Questionnaire were higher in the group with low-level kinesiophobia (P < 0.05).

CONCLUSIONS

As the treatment of pain alone in patients with knee osteoarthritis is not sufficient to reduce fear of movement, we suggest that approaches to increase awareness of fear of movement and physical activity and cognitive behavioral therapy related to fear of movement should be included in the treatment program.

Is being barefoot, wearing shoes and physical activity associated with knee osteoarthritis pain flares? Data from a usually barefoot Sri Lankan cohort

AIM

To identify the association between hours of being barefoot/wearing footwear, physical activity (PA) and knee osteoarthritis pain flares (KOAF).

METHODS

Persons with a diagnosis of knee osteoarthritis, who reported previous KOAF, were followed up in a 3 months long telephone-based case-crossover study. Exposures to risk factors were assessed every 10 days and whenever the participants experienced a KOAF. Conditional logistic regression examined associations of KOAF with following: hours of being barefoot/using footwear and PA performed (P < .05).

RESULTS

There were 260 persons recruited, of whom 183 continued longitudinal follow up. Of them, 120 persons had at least one valid KOAF and control period. Participants were female (90%) with mean (SD) age and body mass index of 59.9 (7.0) years, 28.0 (5.0) kg/m² respectively. Participants were barefoot for a mean duration of 12.7 hours (SD 4.6) and used footwear for 5.1 (SD 4.7) hours daily; 99% wore heel heights <2.5 cm. Duration of being barefoot, 1 and 2 days before, demonstrated reduced multivariate odds of KOAF (odds ratio [OR] = 0.85; 95% CI 0.80-0.90). Moderate PA performed 1, 2 days prior was associated with a significantly increased risk of KOAF (multivariate OR 4.29; 2.52-7.30 and OR 3.36; 2.01-5.61). Similarly, hours of using footwear 1 and 2 days before flare demonstrated increased odds of KOAF (OR 1.15; 1.07-1.23 and 1.10; 1.03-1.18).

CONCLUSIONS

Increased duration of being barefoot 1 to 2 days before is associated with reduced risk of KOAF. Performing moderate PA 1 to 2 days before was associated with an increased risk of KOAF.

Co-existing patterns of MRI lesions were differentially associated with knee pain at rest and on joint loading: a within-person knee-matched case-controls study

BACKGROUND

To assess the association of co-existing MRI lesions with knee pain at rest or on joint loading.

METHODS

We included participants from Osteoarthritis Initiative whose pain score, measured by WOMAC sub-scales, differed by ≥1 point at rest (in bed at night, sitting/lying down) or on joint loading (walking, stairs) between two knees. Cartilage morphology, bone marrow lesions, meniscus extrusion, meniscus morphology, Hoffa's synovitis and synovitis-effusion were assessed using the compartment-specific MRI Osteoarthritis Knee Score. We performed latent class analyses to identify subgroups of co-existing MRI lesions and fitted a conditional logistic regression model to examine their associations with knee pain.

RESULTS

Among 130 eligible participants, we identified five subgroups of knees according to patterns of co-existing MRI lesions: I. minimal lesions; II. mild lesions; III. moderate morphological lesions; IV. moderate multiple reactive lesions; and V. severe lesions. Compared with subgroup I, the odds ratios (ORs) and 95% confidence intervals (CI) of greater pain in bed at night were 1.6 (0.3, 7.2), 2.2 (0.5, 9.5), 6.2 (1.3, 29.6) and 11.2 (2.1, 59.2) for subgroups II-V, respectively. A similar association was observed between aforementioned subgroups and pain with sitting/lying down. The ORs (95% CI) of greater pain with walking were 1.0 (reference), 1.7 (0.5, 6.1), 0.7 (0.2, 2.3), 5.0 (1.4, 18.6) and 7.9 (2.0, 31.5) for subgroup I-V, respectively. The corresponding analysis for pain on stairs showed similar results.

CONCLUSIONS

Distinct patterns of co-existing MRI lesions have different implications for the pathogenesis of osteoarthritic knee pain occurring with/without joint loading.

Adolescents' experiences of fluctuating pain in musculoskeletal disorders: a qualitative systematic review and thematic synthesis

BACKGROUND

Adolescents with chronic musculoskeletal pain experience daily fluctuations in pain. Although not all fluctuations are bothersome, pain flares are a distinct type of symptom fluctuation with greater impact. Since literature on the experience of pain flares is non-existent, the aim of this review was to (i) synthesise the qualitative literature on adolescents' experiences of fluctuating pain in musculoskeletal disorders in order to (ii) identify knowledge gaps to inform future research on pain flares.

METHODS

Electronic databases (CINAHL, MEDLINE, EMBASE, PsycINFO), grey literature and reference lists were searched from inception to June 2018 for qualitative studies reporting adolescents' experiences of pain. Comprehensiveness of reporting was assessed using the Consolidated Criteria for Reporting Qualitative Health Research. Studies were analysed using thematic synthesis.

RESULTS

Of the 3787 records identified, 32 studies (n = 536) were included. Principal findings were synthesised under three key themes: 1) symptom experience, 2) disruption and loss, and 3) regaining control. The first theme (symptom experience) describes adolescent's perception and interpretation of pain fluctuations. The second theme (disruption and loss) describes the physical, social and emotional constraints faced as a result of changes in pain. The third theme (regaining control) describes coping strategies used to resist and accommodate unpredictable phases of pain. Each theme was experienced differently depending on adolescents' characteristics such as their developmental status, pain condition, and the duration of the pain experience.

CONCLUSIONS

Adolescents with chronic musculoskeletal pain live with a daily background level of symptoms which frequently fluctuate and are associated with functional and emotional difficulties. It was not clear whether these symptoms and challenges were experienced as part of 'typical' fluctuations in pain, or whether they reflect symptom exacerbations classified as 'flares'. Further research is needed to explore the frequency and characteristics of pain flares, and how they differ from their typical fluctuations in pain. The review also highlights areas relating to the pain experience, symptom management and health service provision that require further exploration to support more personalised, tailored care for adolescents with chronic musculoskeletal pain.

Characterizing pain flares in adolescent inflammatory and non-inflammatory musculoskeletal disorders: A qualitative study using an interpretative phenomenological approach

BACKGROUND

Adolescents with musculoskeletal disorders experience acute exacerbations in pain, colloquially called "pain flares" in adult literature. This study aimed to explore adolescents' lived experience of pain flares, including what pain flares are, why they occur, how they are managed and what lasting effects they have on adolescents.

METHODS

A sample of 10 adolescents diagnosed with juvenile idiopathic arthritis or chronic idiopathic pain syndrome were recruited from a tertiary hospital in the UK. Data were collected using semi-structured interviews and visual aids, and analysed using interpretative phenomenological analysis.

RESULTS

Four broad themes were identified which describe as a journey of change from participants: (a) daily life with pain, where adolescents report a level of pain that is "normal" for them which they can tolerate and continue their daily routines around; (b) pre-flare period, where adolescents begin to notice pain increasing beyond normal levels and employ preventative strategies to reduce the risk of symptoms developing into a flare; (c) flare period, where adolescents describe the symptoms, frequency, duration, impact and their attempts to manage flares; to their (d) post-flare period, where symptoms begin to return to baseline levels and adolescents take actions to regain the level of normality experienced in daily life.

CONCLUSION

This study has identified a number of components of the pain flare experience. Findings show that pain flares are more than an increase in pain intensity; they are multi-layered and require other features to change. These findings help to differentiate pain flares from typical fluctuations in pain.

Association of weather factors with the risk of pain exacerbations in people with hip osteoarthritis

Objectives: Our objective was to evaluate the association of weather factors with the risk of pain exacerbations in people with symptomatic hip osteoarthritis (OA). Method: Eligible participants with symptomatic hip OA were instructed to log on to the study website and complete questionnaires every 10 days and additionally whenever they considered they were experiencing a pain exacerbation (case period) during the 90 day follow-up. Pain exacerbation was defined as an increase of two points in pain intensity on an 11-point numeric rating scale (0-10) during the follow-up compared with baseline. Each case period was anchored to four control periods within a 35 day interval using a time-stratified approach. Weather data were obtained for both periods from the publicly available meteorological database of the Australian Bureau of Meteorology. We examined the association of weather factors across 72 h before the index date with the risk of pain exacerbation, using conditional logistic regression. Results: Among 252 participants recruited, 129 participants had at least one episode of pain exacerbation and were included in the analysis. A significant dose-response relationship was found between average daily temperature variation in the prior 72 h and risk of pain exacerbations (p = 0.04 for linear trend). There was no significant association between maximum daily temperature, minimum daily temperature, relative humidity, precipitation, or barometric pressure and hip pain exacerbations. Conclusion: The overall results suggest that only daily temperature variation among different weather factors was associated with hip pain exacerbations in people with symptomatic hip OA.

The Association Between Daily Physical Activity and Pain Among Patients with Knee Osteoarthritis: The Moderating Role of Pain Catastrophizing

OBJECTIVE

The primary objective of this study was to examine the day-to-day association between physical activity and pain intensity among a sample of patients with knee osteoarthritis (KOA) and the potential moderation of this association by negative cognitive processes.

METHODS

In this micro-longitudinal daily diary study, KOA patients (N = 121) completed questionnaires assessing pain (Brief Pain Inventory) and psychosocial functioning (pain catrophizing scale, WOMAC McMaster Universities Osteoarthritis Index function, Patient-Reported Outcomes Measurement Information System [PROMIS; anxiety and depression], the Godin-Shephard Leisure-Time Physical Activity questionnaire, the six-minute walking test) and were then asked to report their levels of physical activity and pain intensity once per day for a period of seven days using an electronic diary.

RESULTS

Multilevel modeling analyses indicated that day-to-day increases in physical activity were associated with heightened levels of pain intensity (B = 0.13 SE = 0.03, P < 0.001). In addition, it was revealed that the association between physical activity and pain intensity was moderated by catastrophizing (B = -0.01 SE = 0.002, P < 0.05), with patients scoring higher in catastrophizing showing a relatively stronger link between day-to-day physical activity and increased knee pain. This effect was specific to catastrophizing, as depression and anxiety did not moderate the activity-pain relationship (P > 0.05).

CONCLUSIONS

Our findings suggest that increases in daily physical activity are associated with concurrent increases in KOA patients' levels of knee pain, particularly among patients reporting higher levels of pain catastrophizing. These results may have clinical implications for the design and testing of interventions targeted at reducing catastrophizing and increasing physical activity among patients with chronic osteoarthritis pain.

What Triggers an LBP Flare? A Content Analysis of Individuals' Perspectives

OBJECTIVE

For many, low back pain (LBP) is a lifelong condition with symptoms varying over time. Previous studies have investigated long-term risk factors and triggers for onset of LBP. No study has examined causes for less distinct fluctuations of symptoms, such as "flares," which individuals with LBP identify as a significant and worrisome part of LBP. As little is known about what triggers this type of fluctuation, we aimed to investigate individuals' perspectives on LBP flare triggers.

METHODS

We conducted an online survey of 130 people with LBP, asking what they think triggers their flares. Data were qualitatively examined using content analysis.

RESULTS

Most participants identified biomedical (84.8%) triggers, endorsing physical/biological factors to explain the flare occurrence. Themes included active movements (35% of participants), static postures (28.1%), overdoing a task (5.3%), biomechanical dysfunction (4.4%), comorbidities (4%), lack of exercise (3.3%), work (1.8%), and medications (1.5%). Nonbiomedical triggers were reported by 15.2% and included psychosocial and contextual factors, including psychological state (6%), weather (5%), sleep (2%), diet (1.2%), and fatigue (1%). These results indicate that individuals consider biomedical factors to be the main triggers of LBP flares, but some acknowledge nonbiomedical triggers.

CONCLUSIONS

Study findings contrast with current pain theories, which suggest that there is a need for a reduced emphasis on biomedical causes of LBP pain, especially when persistent. Recognition of patients' views on causes of LBP flares is crucial to better guide clinical practice and inform further research. The validity of triggers identified by LBP patients requires further investigation.

Impact of flare-ups on the lives of individuals with low back pain: A qualitative investigation

OBJECTIVES

Investigating flare-ups has become relevant to understanding and managing low back pain (LBP), particularly because there has been a shift in the conceptualization of LBP from acute or chronic to fluctuating or episodic. Available research mainly consists of quantitative studies, which are unable to fully explore the perspectives of individuals with LBP. This study aimed to address this gap by exploring the changes in individual's lives when they experience LBP flare-up.

DESIGN AND PARTICIPANTS

A qualitative survey of 130 adult participants with LBP was conducted online, and data analyzed via thematic analysis.

RESULTS

The themes from the analysis were: 1) sense of disablement, 2) changes in mood, 3) use of coping strategies, and 4) lack of understanding from other people. Participants described LBP flare-ups as having a negative impact on many areas of their lives, with a few even expressing suicidal ideations.

CONCLUSIONS

Results suggest the importance of considering that LBP flare-ups impact individuals' lives in a complex manner including psychosocial and functional effects. Clinicians should consider this complexity in their interactions with, and management of, patients with LBP flare-ups. Additional education may be required to better equip clinicians for these numerous aspects.

New and emerging treatments for vaso-occlusive pain in sickle cell disease

Introduction: Acute pain from episodic vaso-occlusion (VOC) spans the lifespan of almost everyone with sickle cell disease (SCD), while additional chronic pain develops in susceptible individuals in early adolescences. Frequent acute pain with chronic pain causes significant physical and psychological morbidity, and frequent health-care utilization. Available pharmacologic therapies reduce acute pain frequency but few evidence-based therapies are available for chronic pain. Areas covered: An extensive PubMed literature search was performed with appropriate search criteria. The pathophysiology of acute pain from VOC in SCD is very complex with many events subsequent to sickle polymer formation. Sensitization of pain pathways and alterations of brain networks contributes to the experience of chronic pain. Numerous therapies targeting putative VOC mechanisms are in clinical trials, and show considerable promise. Alternative analgesic treatments for acute and chronic pain have been examined in small patient cohorts, but formal clinical trials are lacking. Expert opinion: Childhood is likely a critical window for prevention of acute and later chronic pain. New multimodal analgesic therapies are needed, particularly for chronic pain, and should be examined in clinical trials. Given the multifactorial nature of both pain and VOC, simultaneously targeting multiple mechanisms may be the optimal approach for effective preventive therapies.

'Acute flare-ups' in patients with, or at high risk of, knee osteoarthritis: a daily diary study with case-crossover analysis

OBJECTIVE

To determine the natural history of flare-ups in knee osteoarthritis and their relation to physical exposures.

DESIGN

Adults aged ≥45 years with a recent primary care consultation for knee OA/arthralgia completed a daily pen-and-paper diary for up to three months, including questions on average knee pain intensity, pain descriptors, other symptoms, activity interference, and selected physical exposures (prolonged kneeling, squatting, climbing stairs, ladders, and moving/lifting heavy objects). Informed by a systematic review, flare-ups were defined a priori. We calculated the rate of flare-ups in the sample, described their nature and duration, and estimated their association with physical exposures in the prior 48 h.

RESULTS

67 participants completed at least one month of diaries, 37 (55%) were female, mean age 62 years (SD 10.6) with a mean body mass index of 24.6 kg/m² (SD 5.1). 30 participants experienced a total of 54 flare-ups (incidence density 1.12 (95%CI 0.80, 1.57) flare-ups/person-days). The median duration of flare-ups was eight days (range: 2-30). During a flare-up participants were more likely to report sharp, throbbing, stabbing, burning pain, swelling, limping, stiffness, being woken by pain, taking more analgesia, and stopping usual activities. Exposure to one or more physical exposure increased the risk of a flare-up in the subsequent 48 h (odds ratio 2.19 (95%CI: 1.22, 4.05)).

CONCLUSIONS

Our study with intensive longitudinal data collection suggests acute flare-ups may be experienced by a substantial number of patients. These episodes often last a week or longer, are disruptive, prompt changes in self-management, and may be triggered by high-loading physical activities.

Developing a Preliminary Definition and Domains of Flare in Knee and Hip Osteoarthritis (OA): Consensus Building of the Flare-in-OA OMERACT Group

Flare in knee and hip osteoarthritis (OA) is more than just an exacerbation of pain. Unstructured, semistructured, and focus group interviews followed by Delphi surveys with patients and health professionals (HP) generated candidate domains of an OA flare. Content analysis of interviews with 29 patients and 16 HP extracted 180 statements, which were grouped into 9 clusters. Delphi consensus with 50 patients (Australia, Canada, and France) and 116 HP (17 countries on 4 continents) identified 5 flare domains: pain, swelling, stiffness, psychological aspects, and effect of symptoms. Elements for a preliminary definition of an OA flare are proposed. Registered at clinicaltrials.govNCT02892058.

Acute Flares of Knee Osteoarthritis (the ACT-FLARE Study): Protocol for a Web-Based Case-Crossover Study in Community-Dwelling Adults

Background

The cardinal feature of osteoarthritis (OA) is pain. Although heterogeneity in pain and function have been demonstrated in the long-term course of OA, the more proximate determinants of acute flare-ups remain less clear. How short-term intermittent or transient exposures trigger acute flare-ups has important implications for effective and sustainable self-management strategies.

Objective

The primary objective of this study is to identify potential triggers of acute flares in knee OA. Secondary objectives are to determine their course and consequences and describe high-risk participant profiles.

Methods

We carried out a Web-based case-crossover study. This study aims to recruit 620 community-dwelling adults aged ≥40 years, resident in England, and who have knee pain, with or without a recorded diagnosis of knee OA, and no preexisting diagnosis of inflammatory arthropathy. Participants will be recruited via 3 routes: (1) general practice registers, (2) offline community advertisement, and (3) online social media advertisement. By using questionnaires comparing periods before participants’ self-reported flare-up episodes (hazard periods) with periods during the study when their knee OA symptoms are stable (control periods), triggers preceding flare-ups will be identified and examined using conditional logistic regression. Time-to-resolution of flare-up will be examined by monitoring people’s daily pain, bothersomeness, and medication usage until the participant reports when their flare-up episode ends. Rates of flare-ups will be examined across different participant and flare characteristics using regression models to identify high-risk participant profiles. A study-specific Patient Advisory Group (PAG) is providing suggestion, input, and ongoing support for all stages of the research process.

Results

Participant recruitment opened in July 2018 and is anticipated to continue for 6 months. The study results will be disseminated through a number of channels, including relevant national or international conferences and peer-reviewed publication in a medical journal, via advocacy or charity organizations, such as Versus Arthritis and across social media. Findings will be fed back to members of our PAG, study participants, and clinicians from participating primary care general practices. The PAG will also take an active role in the overall dissemination strategy.

Conclusions

This study will provide empirical evidence to help patients identify common knee OA flare triggers and provide health care professionals with questions to identify patients at most risk of frequent flare-ups.

International Registered Report Identifier (IRRID)

DERR1-10.2196/13428

A Definition of "Flare" in Low Back Pain: A Multiphase Process Involving Perspectives of Individuals With Low Back Pain and Expert Consensus

Low back pain (LBP) varies over time. Consumers, clinicians, and researchers use various terms to describe LBP fluctuations, such as episodes, recurrences and flares. Although "flare" is use commonly, there is no consensus on how it is defined. This study aimed to obtain consensus for a LBP flare definition using a mixed-method approach. Step 1 involved the derivation of a preliminary candidate flare definition based on thematic analysis of views of 130 consumers in consultation with an expert consumer writer. In step 2, a workshop was conducted to incorporate perspectives of 19 LBP experts into the preliminary flare definition, which resulted in 2 alternative LBP flare definitions. Step 3 refined the definition using a 2-round Delphi consensus with 50 experts in musculoskeletal conditions. The definition favored by experts was further tested with 16 individuals with LBP in step 4, using the definition in three scenarios. This multiphase study produced a definition of LBP flare that distinguishes it from other LBP fluctuations, represents consumers' views, involves expert consensus, and is understandable by consumers in clinical and research contexts: "A flare-up is a worsening of your condition that lasts from hours to weeks that is difficult to tolerate and generally impacts your usual activities and/or emotions." Perspective: A multiphase process, incorporating consumers' views and expert consensus, produced a definition of LBP flare that distinguishes it from other LBP fluctuations.

Acute flares of knee osteoarthritis in primary care: a feasibility and pilot case-crossover study

Background

Osteoarthritis (OA) is a leading cause of persistent pain and disability. Traditionally viewed as a slowly progressive disease, the impact of symptom variability on prognosis remains unclear. 'Acute-on-chronic' episodes are a well-recognised feature of many long-term conditions but only recently formally described in OA. This study aimed to develop a web-based data collection platform and establish key methodological design parameters, to develop a larger community-based study investigating acute flares of knee OA in England.

Methods

The study is a 9-week feasibility and pilot web-based observational case-crossover study. Adults aged ≥ 40 years registered with two general practices who had consulted their general practitioner for knee pain/OA in the last 2 years were recruited. Participants completed a baseline questionnaire and scheduled (control-period) questionnaires at follow-up weeks 1, 5, and 9. Participants were invited to self-declare via the website on any occasion they experienced a knee pain flare-up lasting ≥ 24 h. Upon notification, an event-driven (case-period) questionnaire comparable to the scheduled questionnaires was completed and daily measurements on the course and consequences were taken until resolution. A sub-study of 10 participants logged daily pain measurements. The analysis estimated key parameters including recruitment (selective non-participation, eligibility, consent), retention, and flare-up capture processes. Questionnaire completeness and website usability were evaluated.

Results

Of 442 patients invited, 14 completed baseline questionnaires. Eligibility rate was 26.9% (95% CI 19.3, 36.2), consent rate 53.6% (35.8, 70.5), and overall recruitment rate 3.2% (1.9, 5.2). Compared to those mailed, baseline responders were more likely to be male and ≥ 65 years, as were those reporting ≥ 1 flare-up. Eleven scheduled questionnaires were completed (mean response 35%). Although seven participants (50%) self-declared 11 flare-ups, only one event-driven questionnaire was completed and three participants contributed daily flare measurement for four flares. Missing data was ≤ 3.7% across completed baseline, scheduled, and event-driven questionnaires. Aspects of website usability require minor refinement.

Conclusions

Recruitment was not feasible with the current strategy. An evaluation of processes has suggested several substantial changes in design that may enhance recruitment, retention, and data quality in a future full-scale study.

Effects of carrageenan induced synovitis on joint damage and pain in a rat model of knee osteoarthritis

OBJECTIVE

Knee osteoarthritis (OA) is associated with ongoing pain and joint damage that can be punctuated by acute flares of pain and inflammation. Synovitis in normal knees might resolve without long-term detriment to joint function. We hypothesised that osteoarthritis is associated with impaired resilience to inflammatory flares.

DESIGN

We induced synovitis by injecting carrageenan into rat knees with or without meniscal transection (MNX)-induced OA, and measured synovitis, weightbearing asymmetry (pain behaviour), and joint damage up to 35 days after OA induction (23 days after carrageenan-injection).

RESULTS

Carrageenan injection induced weightbearing asymmetry for 1 week, transient increase in knee diameter for 2 days, and a sustained increase in synovial macrophages, endothelial cell proliferation and vascular density compared with naive vehicle-injected controls. MNX surgery induced weightbearing asymmetry and histological evidence of OA. Carrageenan-injection in MNX-operated knees was followed for 2 days by increased weightbearing asymmetry compared either to MNX+vehicle or to sham+carrageenan groups. OA structural damage and synovitis at day 35 were greater in MNX+carrageenan compared to MNX+vehicle and sham+carrageenan groups. Carrageenan injection did not induce OA in Sham-operated knees.

CONCLUSION

Intra-articular injection of the pro-inflammatory compound carrageenan in OA and sham-operated control knees induced a short term increase in joint pain. Even though pain flares resolved in both groups and damage was not induced in sham-operated knees, carrageen injection exacerbated long-term joint damage in OA knees. OA knees display less resilience to inflammatory episodes. Preventing inflammatory flares may be particularly important in preventing symptoms and long term joint damage in OA.

Defining acute flares in knee osteoarthritis: a systematic review

OBJECTIVE

To identify and critically synthesise definitions of acute flares in knee osteoarthritis (OA) reported in the medical literature.

DESIGN

Systematic review and narrative synthesis. We searched Medline, EMBASE, Web of science and six other electronic databases (inception to July 2017) for original articles and conference abstracts reporting a definition of acute flare (or synonym) in humans with knee OA. There were no restrictions by language or study design (apart from iatrogenic-induced flare-ups, eg, injection-induced). Data extraction comprised: definition, pain scale used, flare duration or withdrawal period, associated symptoms, definition rationale, terminology (eg, exacerbation or flare), baseline OA severity, age, gender, sample size and study design.

RESULTS

Sixty-nine articles were included (46 flare design trials, 17 observational studies, 6 other designs; sample sizes: 15-6085). Domains used to define flares included: worsening of signs and symptoms (61 studies, 27 different measurement tools), specifically increased pain intensity; minimum pain threshold at baseline (44 studies); minimum duration (7 studies, range 8-48 hours); speed of onset (2 studies, defined as 'sudden' or 'quick'); requirement for increased medication (2 studies). No definitions included activity interference.

CONCLUSIONS

The concept of OA flare appears in the medical literature but most often in the context of flare design trials (pain increases observed after stopping usual treatment). Key domains, used to define acute events in other chronic conditions, appear relevant to OA flare and could provide the basis for consensus on a single, agreed definition of 'naturally occurring' OA flares for research and clinical application.

PROSPERO REGISTRATION NUMBER

CRD42014010169.

What constitutes back pain flare? A cross sectional survey of individuals with low back pain

BACKGROUND AND PURPOSE

Low back pain (LBP) is a lifelong problem for many. In acute episodes, or as a persistent condition, LBP is fluctuating in nature, with pain and other features of the condition varying in intensity and duration over time. Symptom flares (also known as flare ups) contribute to this variation and can have a great impact on the lives of those who have LBP. An important goal of treatments for, and research on, LBP is arguably to decrease symptom flare in both frequency and severity. However, this goal is problematic with little research, and no consensus, on how to define LBP flare. In particular, patients' understandings of LBP flare have received limited attention in the literature. To appropriately address this issue, we sought to understand how flares are conceptualized by individuals with LBP.

METHODS

We used an inductive, predominantly qualitative methodology, conducting an online survey with 130 individuals who self-reported experiencing LBP. The survey investigated participants' views on LBP flare including its meaning, features and symptoms, and whether 'flare' and 'pain increase' were synonymous. Qualitative analysis of responses involved thematic and content analysis with descriptive statistics used for the quantitative component.

RESULTS

Our data analysis found that participants identified many aspects of a flare to be important. Qualitative analyses highlighted a number of themes including that LBP flare was conceptualized as: (1) an increase in pain and other uncomfortable sensations such as paraesthesia or muscle tension, (2) an increase in the area, quality and/or duration of symptoms, (3) a reduction in physical, cognitive and/or social functioning, and (4) negative psychological and/or emotional factors. Flare was also discussed as a change that was difficult to settle. When participants considered whether 'flare' and 'pain increase' were synonymous, responses were evenly divided between 'no' (47%) and 'yes' (46%) with remaining participants 'unsure'.

CONCLUSIONS

The key finding was that many people with LBP do not consider their condition to be flared simply on the basis of a pain increase. In general, other features were required to also change. Results highlighted that a narrow focus on pain is unlikely to differentiate minor pain events from a flare. These findings are important as they contrast with most commonly used definitions of a flare that focus predominantly on pain increase.

IMPLICATIONS

Our findings have implications for understanding the trajectory of LBP over time. Understandings derived from perspectives of individuals with LBP highlight that defining flare in LBP is complex. In order to provide person-centred care, individual context and experiences should be taken into account. Therefore, understandings of LBP flare require consideration of factors beyond simply an increase in pain. A comprehensive, person-centred understanding of flare that includes a number of features beyond simply an increase in pain intensity is likely to be useful to better identify flares in research settings, assisting endeavours to understand and reduce LBP. Similarly, in clinical settings a nuanced conceptualisation of flare is likely to help health professionals communicate understandings of flare when working with individuals to manage their LBP.

Defining Flare in Osteoarthritis of the Hip and Knee: A Systematic Literature Review — OMERACT Virtual Special Interest Group

Objective.

Beyond the exacerbation of pain in describing a flare in osteoarthritis (OA), patients and health professionals add other elements that deserve to be fully elucidated, such as effusion, swelling, and mobility limitation. To define and conceptualize the construct flare in OA, the objective was to identify the key variables, or symptoms, that worsen, and to clarify how these variables are described in the literature by patients and clinicians.

Methods.

A systematic review of the literature was conducted in Medline and PsychINFO. In brief, the search terms used were “osteoarthritis,” “knee,” “hip,” and “flare.” Specific characteristics of included studies were identified, including the type of study design, type of flare assessed, how the flare developed, and what definition of flare was used, including whether the definition was based on qualitative or quantitative analysis.

Results.

Pain was the major factor in the definition of flare within these studies. Four components of flare were identified: pain, other factors, composite criteria, and global assessment. While the majority of studies reported flare as an increase in pain using standardized outcome measures, only 1 study reported the antecedents and consequences of a pain flare using qualitative methods.

Conclusion.

The use of flare as an outcome or inclusion criterion in rheumatology trials is a common occurrence; however, this review highlights the wide variation in the definitions of OA flare currently in use and the emphasis on the measurement of pain. This variation in definition does not allow for direct comparison between trials and limits interpretation of evidence.

Osteoarthritis year in review 2015: clinical

The purpose of this review is to highlight clinical research in osteoarthritis (OA). A literature search was conducted using PubMed (http://www.ncbi.nlm.nih.gov/pubmed/) with the search terms "osteoarthritis [All Fields] AND treatment [All Fields]" and the following limits activated: humans, English language, all adult 19+ years, published between April 1, 2014 and April 1, 2015. A second literature search was then conducted with the search terms "osteoarthritis [All Fields] AND epidemiology [All Fields]", with the same limits. Reports of surgical outcome, case series, surgical technique, tissue sample or culture studies, trial protocols, and pilot studies were excluded. Of 1523, 150 were considered relevant. Among epidemiologic and observational clinical studies, themes included physical activity, early knee OA, and confidence/instability/falls. Symptom outcomes of pharmacologic treatments were reported for methotrexate, adalimumab, anti-nerve growth factor monoclonal antibodies, strontium ranelate, bisphosphonates, glucosamine, and chondroitin sulfate, and structural outcomes of pharmacologic treatments for strontium ranelate, recombinant human fibroblast growth factor 18, and glucosamine and chondroitin sulfate. Symptom outcomes of non-pharmacologic interventions were reported for: neuromuscular exercise, quadriceps strengthening, weight reduction and maintenance, TENS, therapeutic ultrasound, stepped care strategies, cognitive behavior therapy for sleep disturbance, acupuncture, gait modification, booster physical therapy, a web-based therapeutic exercise resource center for knee OA; hip physical therapy for hip OA; and joint protection and hand exercises for hand OA. Structure outcomes of non-pharmacologic interventions were reported for patellofemoral bracing.