Short-Term Recovery Trajectories of Acute Flares in Knee Pain: A UK-Netherlands Multicenter Prospective Cohort Analysis

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.

Triggers for acute flare in adults with, or at risk of, knee osteoarthritis: a web-based case-crossover study in community-dwelling adults

OBJECTIVE

To identify proximate causes ('triggers') of flares in adults with, or at risk of, knee osteoarthritis (OA), estimate their course and consequences, and determine higher risk individuals.

METHODS

In this 13-week web-based case-crossover study adults aged ≥40 years, with or without a recorded diagnosis of knee OA, and no inflammatory arthropathy who self-reported a knee flare completed a questionnaire capturing information on exposure to 21 putative activity-related, psychosocial and environmental triggers (hazard period, ≤72 h prior). Comparisons were made with identical exposure measurements at four 4-weekly scheduled time points (non-flare control period) using conditional logistic regression. Flare was defined as a sudden onset of worsening signs and symptoms, sustained for ≥24 h. Flare characteristics, course and consequence were analysed descriptively. Associations between flare frequency and baseline characteristics were estimated using Poisson regression.

RESULTS

Of 744 recruited participants (mean age [SD] 62.1 [10.2] years; 61% female), 376 reported 568 flares (hazards) and provided 867 valid control period measurements. Thirteen exposures (eight activity-related, five psychosocial/environmental) were positively associated with flare onset within 24 h (strongest odds ratio estimate, knee buckling: 9.06: 95% confidence interval [CI] 5.86, 13.99; weakest, cold/damp weather: 1.45: 95%CI 1.12, 1.87). Median flare duration was 5 days (IQR 3, 8), less common if older (incident rate ratio [IRR] 0.98: 95%CI 0.97, 0.99), more common if female (IRR 1.85: 95%CI 1.43, 2.39).

CONCLUSIONS

Multiple activity-related, psychosocial and environmental exposures are implicated in triggering flares. This evidence can help inform prevention and acute symptom management for patients and clinicians.

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.