The relationship between knee pain characteristics and symptom state acceptability in people with knee osteoarthritis

Predictive models of radiographic progression and pain progression in patients with knee osteoarthritis: data from the FNIH OA biomarkers consortium project

OBJECTIVES

The progression of knee osteoarthritis (OA) can be defined as either radiographic progression or pain progression. This study aimed to construct models to predict radiographic progression and pain progression in patients with knee OA.

METHODS

We retrieved data from the FNIH OA Biomarkers Consortium project, a nested case-control study. A total of 600 subjects with mild to moderate OA (Kellgren-Lawrence grade of 1, 2, or 3) in one target knee were enrolled. The patients were classified as radiographic progressors (n = 297), non-radiographic progressors (n = 303), pain progressors (n = 297), or non-pain progressors (n = 303) according to the change in the minimum joint space width of the medial compartment and the WOMAC pain score during the follow-up period of 24-48 months. Initially, 376 variables concerning demographics, clinical questionnaires, imaging measurements, and biochemical markers were included. We developed predictive models based on multivariate logistic regression analysis and visualized the models with nomograms. We also tested whether adding changes in predictors from baseline to 24 months would improve the predictive efficacy of the models.

RESULTS

The predictive models of radiographic progression and pain progression consisted of 8 and 10 variables, respectively, with area under curve (AUC) values of 0.77 and 0.76, respectively. Incorporating the change in the WOMAC pain score from baseline to 24 months into the pain progression predictive model significantly improved the predictive effectiveness (AUC = 0.86).

CONCLUSIONS

We identified risk factors for imaging progression and pain progression in patients with knee OA over a 2- to 4-year period, and provided effective predictive models, which could help identify patients at high risk of progression.

Study on the treatment of osteoarthritis by acupuncture combined with traditional Chinese medicine based on pathophysiological mechanism: A review

Osteoarthritis (OA) is a major contributor to disability and social costs in the elderly. As the population ages and becomes increasingly obese, the incidence of the disease is higher than in previous decades. In recent years, important progress has been made in the causes and pathogenesis of OA pain. Modern medical treatment modalities mainly include the specific situation of the patient and focus on the core treatment, including self-management and education, exercise, and related weight loss. As an important part of complementary and alternative medicine, TCM has remarkable curative effect, clinical safety, and diversity of treatment methods in the treatment of OA. Traditional Chinese Medicine treatment of OA has attracted worldwide attention. Therefore, this article will study the pathophysiological mechanism of OA based on modern medicine, and explore the treatment of OA by acupuncture combined with Chinese Medicine.

Failure in articular cartilage: Finite element predictions of stress, strain, and pressure under micro-indentation induced fracture

Articular cartilage is found at the distal end of long bones and is responsible for assisting in joint articulation. While articular cartilage has remarkable resistance to failure, once initially damaged, degeneration is nearly irreversible. Thus, understanding damage initiation is important. There are a few proposed mechanisms for articular cartilage failure initiation: (A) a single collagen fibril stress-based regime; (B) a rate-dependent regime captured by brittle failure at slow displacement rates (SDR) and ductile failure at fast displacement rates (FDR); and (C) a rate-dependent regime where failure is governed by pressurization fragmentation at SDR and governed by strain at FDR. The objective of this study was to use finite element (FE) models to provide evidence to support or refute these proposed failure mechanisms. Models were developed of microfracture experiments that investigated osmolarity (hypo-osmolar, normal osmolarity, and hyper-osmolar) and displacement rate (FDR and SDR) effects. Cartilage was modeled with a neo-Hookean ground matrix, strain-dependent permeability, nonlinear fibril reinforcement with viscoelastic fibril terms, and Donnan equilibrium swelling. Total stress, solid matrix stress, Lagrange strain, and fluid pressure were determined under the indenter tip at the moment of microfracture. Results indicated significant rate dependence across multiple outputs, which does not support (A) a single failure regime. Larger solid and fluid pressures at FDR than SDR did not support (C) a rate-dependent regime split by pressurization at SDR and strain at FDR. Consistent solid shear stresses at SDR and consistent third principal solid stresses at FDR support (B) the ductile-brittle failure regime. These findings help to shed light on the underlying mechanisms of articular cartilage failure, which have implications for the development of osteoarthritis.

Pentraxin 3 deficiency ameliorates the severity of osteoarthritis and alleviates inflammation

BACKGROUND

Osteoarthritis is one of the most common degenerative joint disorders, characterized by articular cartilage breakdown, synovitis, osteophytes generation and subchondral bone sclerosis. Pentraxin 3 (PTX3) is a long pentraxin protein, secreted by immune cells, and PTX3 is identified to play a critical role in inflammation and macrophage polarization. However, the underlying mechanism of PTX3 in osteoarthritis under the circumstance of Ptx3-knockout (KO) mice model is still unknown.

METHODS

Murine destabilization of the medial meniscus (DMM) OA model was created in Ptx3-knockout (KO) and wildtype mice, respectively. The degenerative status of cartilage was detected by Safranin O, H&E staining, immunohistochemistry (IHC) and micro-CT. OARSI scoring was employed to assess the proteoglycan of cartilage. Serum inflammatory cytokines were examined by ELISA and systematic macrophage polarization in spleen was analyzed by flow cytometry.

RESULTS

Safranin O and H&E staining confirmed that the joint cartilage was mostly with reduced degeneration in both the senior KO mice and the DMM model generated from the KO mice, compared to the WT group. This is also supported by micro-CT examination and OARSI scoring. Immunohistochemistry illustrated an up-regulation of Aggrecan and Collagen 2 and down-regulation of ADAMTS-5 and MMP13 in KO mice in comparison with the WT mice. ELISA indicated a dramatical decrease in the serum levels of TNF-α and IL-6 in KO mice. Polarization of M2-like macrophages was observed in the KO group.

CONCLUSION

Pentraxin 3 deficiency significantly ameliorated the severity of osteoarthritis by preventing cartilage degeneration and alleviated systematic inflammation by inducing M2 polarization.

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.

Factors associated with clinically relevant pain reduction after a self-management program including education and exercise for people with knee and/or hip osteoarthritis: Data from the BOA register

AIM

To examine the associations between individual- and disease-related factors and the odds of reaching a clinically relevant pain reduction in people with knee and/or hip osteoarthritis (OA) who underwent a first-line self-management program.

MATERIALS AND METHODS

An observational registry-based study including people with knee (n = 18,871) and hip (n = 7,767) OA who participated in a self-management program including education and exercise and had data recorded in the Better Management of patients with Osteoarthritis (BOA) register. We used multivariable logistic regression models to study the association between sex, age, body mass index (BMI), education, comorbidity, pain frequency, walking difficulties, willingness to undergo surgery and the odds of reaching a clinically relevant pain reduction (decrease of >33% on a 0-10 NRS scale) 3 and 12 months after the intervention. All analyses were stratified by joint (knee/hip).

RESULTS

Both in the short- and long-term follow-up, a younger age (18-65 years), a lower BMI (< 25), a higher level of education (university), the absence of comorbidities impacting the ability to walk, less frequent pain and not being willing to undergo surgery were associated with higher odds of reaching a clinically relevant pain reduction in people with knee OA. We found similar results for people with hip OA, but with larger uncertainty in the estimates (wider 95% CI).

CONCLUSION

Our study suggests that early fist line self-management interventions delivered when people have unilateral hip or knee OA with less frequent pain and are unwilling to undergo surgery, may be important for reaching a clinically relevant pain reduction after participation. Providing the most appropriate treatment to the right patient at the right time is a step in reducing the burden of OA for society and the patient.

Pharmacological use of gamma-aminobutyric acid derivatives in osteoarthritis pain management: a systematic review

Background

Pain is the major complication of osteoarthritis (OA) patients and is a decisive symptom for medical intervention. Gamma-aminobutyric acid (GABA) derivatives are optional painkillers but not widely used in pain management of OA patients. We synthesized the efficacy and safety of GABA derivatives for OA pain management.

Methods

We searched Medline, Cochrane CENTRAL, Embase, and ClinicalTrals.gov from inception to 13 October 2021 and included randomized controlled trials (RCTs) comparing the efficacy and safety of GABA derivatives with placebo or standard control in OA pain management. Two independent reviewers extracted data and assessed these studies for risk of bias using Cochrane Collaboration’s tool for RCT.

Results

In total, three eligible RCTs (n = 3) meeting the eligibility criteria were included. Among these RCTs, one focused on hand OA pain management, while two RCTs focused on knee OA. In hand OA, pregabalin reduced numerical rating scale (NRS) score and the Australian/Canadian Osteoarthritis Hand Index (AUSCAN) pain score significantly compared with placebo, and caused 55 AEs. In knee OA, pregabalin reduced visual analogue scale (VAS) score and the Western Ontario and McMaster Universities Arthritis Index (WOMAC) pain score significantly with no recorded adverse event (AE). Meanwhile, in knee OA, gabapentin reduced both VAS score and WOMAC pain score compared with acetaminophen and caused 9 AEs.

Conclusions

GABA derivatives seem to be effective and safe in OA pain management. However, future researches with large sample size are needed to further prove the efficacy of GABA derivatives in OA pain control.

Trial registration: CRD42021240225.

Supplementary Information

The online version contains supplementary material available at 10.1186/s41927-022-00257-z.

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.

Is Chronic Pain Temporal Pattern Associated with Middle-Aged and Older Adults’ Perceptions of their Futures?

A psychological consequence of chronic pain may be an inappropriately limited future time perspective (FTP) for middle-aged and older adults. FTP is defined as one’s perception of time as limited or expansive. Potentially meaningful measures, like pain temporal pattern, are often ignored in the chronic pain literature. The present study uses secondary data to assess the association between pain temporal pattern and FTP, and the moderating effect of pain duration. Among 140 individuals with chronic pain, there was no significant association between pain pattern and FTP. However, both pain-related activity interference and pain duration were associated with FTP where greater interference predicted more limited FTP (b = −0.16, p = .03) and longer pain duration contributed to more expansive FTP (b = 0.001, p = .03). The temporal pattern x pain duration interaction terms were non-significant. We discuss implications, limitations, and future directions of these findings.

A Review of Non-Surgical Pain Management in Osteoarthritis

Osteoarthritis is a prominent cause of disability in older adults, especially with an increasingly obese and aging population. Clinical management of pain secondary to osteoarthritis should focus on education and self-management with exercise and weight management as a priority. Surgical intervention should only be considered once conservative measures have failed. This review provides a clinical update on the pathogenesis, diagnosis, and management of osteoarthritis.

Use of prescription analgesic drugs before and after hip or knee replacement in patients with osteoarthritis

BACKGROUND

Analgesic drugs are recommended to treat pain caused by osteoarthritis, and joint replacement should decrease the need for them. We aimed to determine the user rates of analgesic drugs before and after joint replacement.

METHODS

All patients who underwent a primary hip or knee replacement for osteoarthritis from 2002 to 2013 in a region of 0.5 million people were identified. Patients with revision or other joint replacements during the study period (operation date +/- two years) were excluded, leaving 6238 hip replacements (5657 patients) and 7501 knee replacements (6791 patients) for analyses. Medication data were collected from a nationwide Drug Prescription Register and the prevalence (with its 95% confidence intervals) of acetaminophen, non-steroidal anti-inflammatory drugs (NSAIDs), mild opioids, strong opioids, and medications used for neuropathic pain was calculated in three-month periods two years before and after surgery.

RESULTS

Between two years and three months preoperatively, the proportion of patients who redeemed at least one type of analgesic drug increased from 28% (95% CI, 27-30%) to 48% (47-50%) on hip replacement patients and from 33% (32-34%) to 41% (40-42%) on knee replacement patients. Postoperatively, the proportions decreased to 23% (22-24%) on hip and to 30% (29-31%) on knee patients. Hip replacement patients used more NSAIDs (34% (32-35%) hip vs 26% (25-27%) knee, p < 0.001), acetaminophen (14% (13-15%) vs 12% (11-13%), p < 0.001), and mild opioids (14% (13-15%) vs 9% (8-9%), p < 0.001) than knee patients preoperatively, but postoperatively hip patients used less NSAIDs (12% (11-13%) vs 16% (15-16%), p < 0.001), acetaminophen (9% (8-10%) vs 11% (11-12%), p < 0.001), and mild opioids (5% (5-6%) vs 8% (7-8%), p < 0.001).

CONCLUSION

Use of analgesic drugs increases prior to joint replacement, and is reduced following surgery. However, a considerable proportion of patients continue to use analgesics in two-year follow-up.

Osteoarthritis

Osteoarthritis is a leading cause of disability and source of societal cost in older adults. With an ageing and increasingly obese population, this syndrome is becoming even more prevalent than in previous decades. In recent years, we have gained important insights into the cause and pathogenesis of pain in osteoarthritis. The diagnosis of osteoarthritis is clinically based despite the widespread overuse of imaging methods. Management should be tailored to the presenting individual and focus on core treatments, including self-management and education, exercise, and weight loss as relevant. Surgery should be reserved for those that have not responded appropriately to less invasive methods. Prevention and disease modification are areas being targeted by various research endeavours, which have indicated great potential thus far. This narrative Seminar provides an update on the pathogenesis, diagnosis, management, and future research on osteoarthritis for a clinical audience.

Relationship of knee pain to time in moderate and light physical activities: Data from Osteoarthritis Initiative

INTRODUCTION

While OA literature indicates greater pain is related to less time being physically active, it is not known if time curtailment occurs primarily for moderate intensity activities or for light activities or in both. We examine the cross-sectional association of knee pain with physical activity using data from 1874 Osteoarthritis Initiative participants.

METHODS

Knee pain characteristics of constant and intermittent pain were each scored by the Intermittent and Constant Osteoarthritis Pain instrument and categorized into four pain levels (no pain, intermittent pain below and above median level, and constant pain). The relationships between knee pain levels and objectively measured physical activity (average weekly moderate or light intensity minutes) were assessed by quantile regression adjusted for socio-demographics and health factors.

RESULTS

Knee pain levels had a strong negative relationship with moderate intensity physical activities (p-value for trend =0.029). Compared to the no pain group, persons with more severe knee pain, particularly those reporting higher intermittent or constant pain spent less time in moderate activity. In contrast, there was no notable trend related to pain with time spent in light intensity activity. These patterns remained when restricted to persons with clinical evidence (symptoms and/or radiographic) of knee OA and among persons not using medications for knee symptoms.

CONCLUSION

Greater knee pain levels were strongly related to less moderate intensity activity time, but not time spent in light intensity physical activity. This relationship suggests that light activity may be a more acceptable way to increase physical activity than moderate activity for people with symptomatic knee pain.

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.

Effects of Treadmill Exercise on Advanced Osteoarthritis Pain in Rats

OBJECTIVE

Exercise is commonly recommended for patients with osteoarthritis (OA) pain. However, whether exercise is beneficial in ameliorating ongoing pain that is persistent, resistant to nonsteroidal antiinflammatory drugs (NSAIDs), and associated with advanced OA is unknown.

METHODS

Rats treated with intraarticular (IA) monosodium iodoacetate (MIA) or saline underwent treadmill exercise or remained sedentary starting 10 days postinjection. Tactile sensory thresholds and weight bearing were assessed, followed by radiography at weekly intervals. After 4 weeks of exercise, ongoing pain was assessed using conditioned place preference (CPP) to IA or rostral ventromedial medulla (RVM)-administered lidocaine. The possible role of endogenous opioids in exercise-induced pain relief was examined by systemic administration of naloxone. Knee joints were collected for micro-computed tomography (micro-CT) analysis to examine pathologic changes to subchondral bone and metaphysis of the tibia.

RESULTS

Treadmill exercise for 4 weeks reversed MIA-induced tactile hypersensitivity and weight asymmetry. Both IA and RVM lidocaine D35, administered post-MIA, induced CPP in sedentary but not exercised MIA-treated rats, indicating that exercise blocks MIA-induced ongoing pain. Naloxone reestablished weight asymmetry in MIA-treated rats undergoing exercise and induced conditioned place aversion, indicating that exercise-induced pain relief is dependent on endogenous opioids. Exercise did not alter radiographic evidence of OA. However, micro-CT analysis indicated that exercise did not block lateral subchondral bone loss or trabecular bone loss in the metaphysis, but did block MIA-induced medial bone loss.

CONCLUSION

These findings support the conclusion that exercise induces pain relief in advanced, NSAID-resistant OA, likely through increased endogenous opioid signaling. In addition, treadmill exercise blocked MIA-induced bone loss in this model, indicating a potential bone-stabilizing effect of exercise on the OA joint.

Transcultural adaptation and validation of the Chinese version of the intermittent and constant osteoarthritis pain (ICOAP) measure in patients with knee osteoarthritis

OBJECTIVE

This study aimed to translate and adapt the intermittent and constant osteoarthritis pain (ICOAP) measure into the Chinese language (ICOAP-C), and to study its psychometric properties in patients with knee osteoarthritis (OA).

DESIGN

The ICOAP was translated and cognitively pretested following internationally recommended guidelines. The reliability, including the internal consistency and the test-retest reliability, was then evaluated in 108 outpatients with knee OA. The validity was assessed by comparing the ICOAP-C with the Western Ontario and McMaster Universities Osteoarthritis Index Pain Subscale (WOMAC-PS), the Knee Injury and Osteoarthritis Outcome Score Pain Short-Form (KOOS-PS), and pain on a visual analogue scale (VAS). Seventy-four patients undergoing total knee arthroplasty (TKA) participated in the evaluation of the responsiveness of the ICOAP-C over a 6-month period.

RESULTS

All participants completed the questionnaires, and no floor or ceiling effects were found. All ICOAP-C scales exhibited satisfactory internal consistency. The intraclass correlation coefficients (ICCs) were excellent, i.e., 0.932 for "total pain", 0.908 for "intermittent pain" and 0.892 for "constant pain". Regarding the convergent validity, the ICOAP-C scores exhibited strong correlations with the WOMAC-PS and moderate correlations with the KOOS-PS and the VAS. The responsiveness of the ICOAP-C at 6 months after TKA was good [standardized response mean (SRM) range: 0.94-1.20; effect size (ES) range: 1.41-1.71].

CONCLUSIONS

The ICOAP-C exhibited good reliability, validity, and responsiveness. This scale is a reliable instrument for evaluating the pain experiences of patients with knee OA and is useful for outcome measurement in clinical research.

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

OBJECTIVE

Although pain in knee osteoarthritis (OA) commonly affects activity engagement, the daily pain experience has not been fully characterized. Specifically, the nature and impact of pain flares is not well understood. This study characterized pain flares as defined by participants with knee OA. Pain flare occurrence and experience were measured over 7 days.

METHODS

This was a multiple methods study; qualitative methods were dominant. Data were collected during the baseline portion of a randomized controlled trial. Participants met criteria for knee OA and had moderate to severe pain. They completed questionnaires and a 7-day home monitoring period that captured momentary symptom reports simultaneously with physical activity via accelerometry (n = 45). Participants also provided individual definitions of pain flare that were used throughout the home monitoring period to indicate whether a pain flare occurred.

RESULTS

Pain flares were described most often by quality (often sharp), followed by timing (seconds, minutes) and by antecedents and consequences. When asked if their definition of a flare agreed with a supplied definition, 49% of the sample reported only "somewhat," "a little," or "not at all." Using individual definitions, 78% experienced at least 1 daily pain flare over the home monitoring period; 24% had a flare on more than 50% of the monitored days.

CONCLUSION

Pain flares were common, fleeting, and often experienced in the context of activity engagement. Participants' views on what constitutes a pain flare differ from commonly accepted definitions. Pain flares are an understudied aspect of the knee OA pain experience and require further characterization.

Pain sensitisation and the risk of poor outcome following physiotherapy for patients with moderate to severe knee osteoarthritis: protocol for a prospective cohort study

INTRODUCTION

Pain is the dominant symptom of knee osteoarthritis (OA), and recent evidence suggests factors outside of local joint pathology, such as pain sensitisation, can contribute significantly to the pain experience. It is unknown how pain sensitisation influences outcomes from commonly employed interventions such as physiotherapy. The aims of this study are, first, to provide a comprehensive description of the somatosensory characteristics of people with pain associated with knee OA. Second, we will investigate if indicators of pain sensitisation in patients with knee osteoarthritis are predictive of non-response to physiotherapy.

METHODS AND ANALYSIS

This is a multicentre prospective cohort study with 140 participants. Eligible patients with moderate to severe symptomatic knee osteoarthritis will be identified at outpatient orthopaedic and rheumatology clinics. A baseline assessment will provide a comprehensive description of the somatosensory characteristics of each participant by means of clinical examination, quantitative sensory testing, and validated questionnaires measuring pain and functional capacity. Participants will then undergo physiotherapy treatment. The primary outcome will be non-response to physiotherapy on completion of the physiotherapy treatment programme as defined by the Osteoarthritis Research Society International treatment responder criteria. A principal component analysis will identify measures related to pain sensitisation to include in the predictive model. Regression analyses will explore the relationship between responder status and pain sensitisation while accounting for confounders.

ETHICS AND DISSEMINATION

This study has been approved by St James' Hospital/AMNCH Research Ethics Committee and by the St Vincent's Healthcare Group Ethics and Medical Research Committee. The results will be presented at international conferences and published in a peer review journal.

TRIAL REGISTRATION NUMBER

NCT02310945.

Intermittent and constant pain and physical function or performance in men and women with knee osteoarthritis: data from the osteoarthritis initiative

Severe constant and intermittent knee pain are associated with "unacceptable" symptoms in older adults with osteoarthritis (OA) [22]. We hypothesized that constant and intermittent pain would be independently related to physical function, with intermittent knee pain being a better predictor of future declines in physical function in early symptomatic knee OA. This study included men (n = 189) and women (n = 133) with radiographic, unilateral knee OA, observed using data from the Osteoarthritis Initiative (OAI). Pain types were measured using the Intermittent and Constant Osteoarthritis Pain (ICOAP) scale. Physical function was measured using the Western Ontario and McMaster Universities Arthritis Index (WOMAC-PF) and Knee Injury and Osteoarthritis Outcome Score (KOOS-FSR) and physical performance tests. High baseline intermittent (B = 0.277; p = 0.001) and constant (B = 0.252; p = 0.001) knee pain were related to poor WOMAC-PF. Increased constant (B = 0.484; p = 0.001) and intermittent (B = 0.104; p = 0.040) pain were related to 2-year decreased WOMAC-PF. High baseline intermittent knee pain predicted poor KOOS-FSR at year 2 (B = -0.357; p = 0.016). Increased constant pain was related to decreased chair stand test performance over 2 years in women (B = 0.077; p = 0.001). High baseline intermittent pain was related to poor performance on repeated chair stands (B = 0.035; p = 0.021), while baseline constant pain was related to poor 400-m walk performance in women (B = 0.636; p = 0.047). Intermittent and constant knee pain were independent factors in self-perceived physical function and were important predictors of future limitations in physical function. Identifying intermittent and constant pain in early symptomatic OA may allow patients to adopt strategies to prevent worsening pain and future declines in physical function.