Correlates of Pain Intensity in Men and Women With Hip and Knee Osteoarthritis. Results of a National Survey: The French ARTHRIX Study

Phenotypes of osteoarthritis-related knee pain and their transition over time: data from the osteoarthritis initiative

BACKGROUND

Identification of knee osteoarthritis (OA) pain phenotypes, their transition patterns, and risk factors for worse phenotypes, may guide prognosis and targeted treatment; however, few studies have described them. We aimed to investigate different pain phenotypes, their transition patterns, and potential risk factors for worse pain phenotypes.

METHODS

Utilizing data from the Osteoarthritis Initiative (OAI), pain severity was assessed using the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) pain subscale. We identified the activity-related pain phenotypes and estimated the transition probabilities of pain phenotypes from baseline to the 24-month using latent transition analysis. We examined the risk factors at baseline with the 24-month pain phenotypes and the transition of pain phenotypes.

RESULTS

In 4796 participants, we identified four distinct knee pain phenotypes at both baseline and 24-month follow-up: no pain, mild pain during activity (Mild P-A), mild pain during both rest and activity (Mild P-R-A), and moderate pain during both rest and activity (Mod P-R-A). 82.9% knees with no pain at baseline stayed the same at 24-month follow-up, 17.1% progressed to worse pain phenotypes. Among "Mild P-A" at baseline, 32.0% converted to no-pain, 12.8% progressed to "Mild P-R-A", and 53.2% remained. Approximately 46.1% of "Mild P-R-A" and 54.5% of "Mod P-R-A" at baseline experienced remission by 24-month. Female, non-whites, participants with higher depression score, higher body mass index (BMI), higher Kellgren and Lawrence (KL) grade, and knee injury history were more likely to be in the worse pain phenotypes, while participants aged 65 years or older and with higher education were less likely to be in worse pain phenotypes at 24-month follow-up visit. Risk factors for greater transition probability to worse pain phenotypes at 24-month included being female, non-whites, participants with higher depression score, higher BMI, and higher KL grade.

CONCLUSIONS

We identified four distinct knee pain phenotypes. While the pain phenotypes remained stable in the majority of knees over 24 months period, substantial proportion of knees switched to different pain phenotypes. Several socio-demographics as well as radiographic lesions at baseline are associated with worse pain phenotypes at 24-month follow-up visit and transition of pain phenotypes.

Prevalence and Characteristics of Knee Osteoarthritis Among the General Public in Saudi Arabia

Background Knee osteoarthritis (OA) is a chronic and progressive knee joint condition that is influenced by multiple factors. This research aims to examine the prevalence and characteristics of knee OA among the general public in Saudi Arabia. Methodology This cross-sectional online survey was conducted in September 2023 in Saudi Arabia. This research used a previously developed questionnaire to validate the diagnosis of OA, which was performed in accordance with the diagnostic criteria established by the American College of Rheumatology (ACR). The Western Ontario and McMaster Universities Arthritis Index questionnaire (WOMAC) was used to examine the severity and characteristics of knee OA patients. A binary logistic regression analysis was conducted to determine the variables that influence the severity of knee OA and the likelihood of developing OA. Results A total of 1,019 individuals participated in this study. Around one-third of the participants (34.5%) fulfilled the ACR criteria for knee OA diagnosis. Overall, the mean WOMAC score was 34.1 (18.8) out of 96, which represents 35.5% of the maximum obtainable score and demonstrates a low degree of knee OA severity. The mean pain sub-scale score was 7.4 (3.8) out of 20, which represents 37.0% of the maximum obtainable score and demonstrates a low level of pain intensity. The mean stiffness sub-scale score was 2.7 (1.8) out of 8, which represents 33.8% of the maximum obtainable score and demonstrates a low degree of stiffness in joints. The mean physical function sub-scale score was 24.0 (14.0) out of 68, which represents 35.3% of the maximum obtainable score and demonstrates a low level of physical function difficulty. Females, older participants (above 40 years), those with high body mass index (28.8 kg/cm2 and higher), non-smokers, those with comorbidities, those who did not practice daily physical activity, those who had a family history of knee OA, and those who suffered from flat feet, rheumatoid arthritis, gout, lupus, or back or hip pain were more likely to develop knee OA and have severe OA (p < 0.05). Conclusions The findings of this study demonstrated a significant prevalence rate of knee OA and highlighted a discrepancy between the rates obtained by diagnostic criteria and those determined through clinical diagnosis. Several significant factors that contribute to the development of OA encompass lifestyle choices such as food and exercise, familial predisposition, genetic influences, and the presence of comorbidities. To effectively tackle this intricate matter, it is imperative to adopt a patient-centered strategy and prioritize early intervention.

Pain in osteoarthritis from a symptom to a disease

Pain is the most frequent symptom of osteoarthritis (OA), occurring much more commonly than stiffness or disability. Classically, OA-related pain has been considered to be a nociceptive pain condition and an alarm signal correlated to the intensity of joint degradation. However, OA-related pain is a specific disease, with a complex pathophysiology, including neuropathic peripheral and central abnormalities, together with local inflammation involving all joint structures. Clinical findings emphasize that it is not a stable and linear condition, that pain experience is poorly correlated to structural modifications, and that the quality of pain in OA is important to consider, aside from its intensity. OA-related pain is modulated by many factors, including the individual patient's psychological and genetic factors, as well as the theoretical role of meteorological influences. Recent findings have improved our knowledge about the central mechanisms of OA pain, especially in persistent cases. A specific questionnaire on OA pain is currently being developed to assess more precisely the patient's experience and target specific pain mechanisms. In conclusion, OA-related pain should be analyzed specifically aside from OA, taking into account the complexity of OA pain as a disease, distinguishing different OA pain phenotypes, to guide more precisely analgesic treatment and OA global management.

Strategies for increasing gait speed in patients with hip osteoarthritis: their clinical significance and effects on hip loading

Background

Changes in gait speed are required in various situations and can be achieved by changing stride length, cadence, or both. Differences in strategies for increasing gait speed may have different effects on hip joint and physical function. The purpose of this study was to determine the effects of strategies for increasing gait speed on hip pain, physical function, and changes in hip loading during gait in patients with hip osteoarthritis (OA). We hypothesized that patients who increase gait speed mainly by increasing cadence would have lesser hip pain, a higher physical function, and a lower rate of increase in hip moments with increasing gait speed.

Methods

Forty-seven patients with secondary hip OA (age, 48.3 ± 11.0 years) were included. Gait speed, stride length, cadence, and peak and impulse of the hip moments were measured during gait at self-selected normal and fast gait speeds. The patients were classified as types S (with mainly increasing stride length, n = 11 [23.4%]), C (with mainly increasing cadence, n = 23 [48.9%]), and SC (with increasing stride length and cadence, n = 13 [27.7%]) according to whether they used changes in stride length and/or cadence to transition from normal to fast gait. Hip pain, physical function, and hip moment changes during gait were compared between types.

Results

The physical function was higher in types C (38.0 ± 8.8, P = 0.018) and SC (40.6 ± 8.5, P = 0.015) than in type S (28.2 ± 7.8), even after adjustment for age and minimum joint space width. Hip pain was not significantly different between types. The robustness of these results was confirmed with sensitivity analysis. The rates of increases in peak external hip adduction (P = 0.003) and internal rotation moments (P = 0.009) were lower in type C than in type SC.

Conclusions

Type C tended to suppress the increase in hip moments during fast gait. Types C and SC, which included increased cadence, maintained higher physical function levels than type S. Encouraging the use of cadence-increasing strategy may be useful for reducing hip loading and maintaining physical function in patients with hip OA.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13075-021-02514-x.

Physical activity and health-related quality of life in men and women with hip and/or knee osteoarthritis before and after a supported self-management programme - a prospective observational study

PURPOSE

To study differences between men and women in physical activity (PA) and health-related quality of life (HRQoL) before and after participating in a supported osteoarthritis (OA) self-management programme.

MATERIALS AND METHODS

A prospective observational study using data from a Swedish National Quality Register. Patients recorded between 2008 and 2013 with hip and/or knee OA with data at baseline, at 3 and 12 months follow-up (n = 7628) were included. Outcome measures were patient-reported PA and HRQoL (EQ-5D-3L).

RESULTS

A greater proportion of men (p = 0.002) changed to being physically active ≥150 min/week at 3 months follow-up. The proportion of women being physically active ≥150 min/week was larger than for men at baseline (p = 0.003) and at follow-up at 12 months (p = 0.035). Women reported lower HRQoL than men at baseline (p < 0.001), at follow-up at 3 (p < 0.001) and 12 months (p = 0.010). There were no differences between men and women in change in HRQoL at 3 (p = 0.629) and 12 months (p = 0.577) follow-up.

CONCLUSIONS

This study showed differences between men and women in PA and HRQoL before and after participating in a supported OA self-management programme. These differences should be considered when supporting PA and HRQoL.Implications for rehabilitationMen with hip and/or knee osteoarthritis (OA) might need more support during rehabilitation in order to maintain or even increase physical activity (PA) in the long run.Women with hip and/or knee OA might need more support during rehabilitation in order to maintain or even increase health-related quality of life (HRQoL) in the long run.Booster sessions might be suggested in order to enable both men and women with hip and/or knee OA to sustain improvements in PA and HRQoL after participating in a supported OA self-management programme.

Toward Understanding Movement-evoked Pain (MEP) and its Measurement: A Scoping Review

OBJECTIVE

Individuals with chronic pain conditions often report movement as exacerbating pain. An increasing number of researchers and clinicians have recognized the importance of measuring and distinguishing between movement-evoked pain (MEP) and pain at rest as an outcome. This scoping review maps the literature and describes MEP measurement techniques.

MATERIALS AND METHODS

The scoping review utilized 6 databases to identify original studies that targeted pain or movement-related outcomes. Our search returned 7322 articles that were screened by title and abstract by 2 reviewers. The inclusion criteria focused on the measurement of MEP before, during, and after movement tasks in adults with chronic pain. Studies of children below 18 years of age or with nonhuman animals, case studies, qualitative studies, book chapters, cancer-related pain, non-English language, and abstracts with no full publish text were excluded from the study.

RESULTS

Results from 38 studies revealed great variation in the measurement of MEP, while almost all of the studies did not provide an explicit conceptual or operational definition for MEP. In addition, studies collectively illuminated differences in MEP compared with rest pain, movement provocation methods, and pain intensity as the primary outcome.

DISCUSSION

These results have clinically significant and research implications. To advance the study of MEP, we offer that consistent terminology, standardized measurement (appropriate for pain type/population), and clear methodological processes be provided in research publications. On the basis of the findings, we have put forth a preliminary definition of MEP that may benefit from the continued scholarly dialog.

Molecular Mechanisms of Sex-Related Differences in Arthritis and Associated Pain

Clinical conditions leading to chronic pain show important sex-related differences in the prevalence, severity, and degree of functional disability. Decades of epidemiological and clinical studies have demonstrated that women are more sensitive to pain than men. Arthritis, including rheumatoid arthritis (RA) and osteoarthritis (OA), is much more prevalent in females and accounts for the majority of pain arising from musculoskeletal conditions. It is therefore important to understand the mechanisms governing sex-dependent differences in chronic pain, including arthritis pain. However, research into the mechanisms underlying the sex-related differences in arthritis-induced pain is still in its infancy due to the bias in biomedical research performed largely in male subjects and animals. In this review, we discuss current advances in both clinical and preclinical research regarding sex-related differences in the development or severity of arthritis and associated pain. In addition, sex-related differences in biological and molecular mechanisms underlying the pathogenesis of arthritis pain, elucidated based on clinical and preclinical findings, are reviewed.

The Relationship Between Daily Physical Activity and Pain in Individuals with Knee Osteoarthritis

Objective

Investigate the association between physical activity and pain severity in individuals with knee osteoarthritis.

Design

Cross-sectional; systematic review with meta-analyses.

Methods

Thirty-one participants with knee osteoarthritis underwent assessment of symptoms via self-report questionnaires and quantitative sensory testing. Following testing, physical activity and symptoms were monitored for seven days using accelerometers and logbooks. Cross-correlation analyses were performed on fluctuations in symptoms and physical activity across the week to detect the relative timing of the strongest association between pain and activity. These data were complemented by meta-analyses of studies that examined correlations between pain from knee osteoarthritis and physical activity or fitness.

Results

Pain severity at baseline correlated with moderate to vigorous physical activity (r2 = 0.161–0.212, P &lt; 0.05), whereby participants who were more physically active had less pain. Conversely, the peak of the cross-correlation analyses was most often positive and lagging, which indicated that pain was increased subsequent to periods of increased activity. These superficially discrepant findings were supported by the results of a meta-analysis of 13 studies and 9,363 participants, which identified significant heterogeneity for associations between physical activity and pain (I2 = 91%). Stronger inverse associations were found between fitness and pain.

Conclusions

Associations between physical activity and pain in people with knee osteoarthritis are variable and dynamic. These results reflect the beneficial impact of an active lifestyle and accompanying higher fitness. Yet, the side effect of acute periods of physical activity to transiently exacerbate pain may influence the behavior of some people to avoid activity because of pain.

A novel device to measure static hindlimb weight-bearing forces in pronograde rodents

BACKGROUND

Joint pain is composed of both spontaneous and movement-induced pain. In animal models, static bodyweight distribution is a surrogate for spontaneous joint pain. However, there are no commercially-available instruments that measure static bodyweight distribution in normal, pronograde rodents.

NEW METHOD

We designed a Static Horizontal Incapacitance Meter (SHIM) to measure bodyweight distribution in pronograde standing rodents. We assessed the device for feasibility, repeatability, and sensitivity to quantify hindlimb bodyweight distribution. Mice and rats with unilateral inflammatory pain induced by subcutaneous injections of capsaicin or Complete Freund's Adjuvant (CFA) into the plantar surface of the left hind paw were used to measure static weight-bearing. The ability to attenuate inflammatory pain-associated weight-bearing asymmetry was tested by administering a non-steroidal anti-inflammatory drug, meloxicam.

RESULTS

The SHIM's ability to detect significant reductions in limb loading on the injected hindlimb in mice and rats was validated using both acute and sub-chronic pain models. Treatment with meloxicam partially reversed CFA-induced effects.

COMPARISON WITH EXISTING METHODS

In contrast with assays that measure kinetic or static weight-bearing forces (e.g., walking, or standing at a 45 ° incline), the SHIM allows evaluation of weight-bearing in rodents that are standing at rest in their normal pronograde position.

CONCLUSIONS

The SHIM successfully detected: (a) asymmetric weight-bearing in acute and sub-chronic pain models; and (b) the analgesic effects of meloxicam. This study provides a novel tool to objectively evaluate limb use dysfunction in rodents.

Younger age is associated with greater pain expression among patients with knee or hip osteoarthritis scheduled for a joint arthroplasty

BACKGROUND

This study describes how patients with knee or hip osteoarthritis (OA), scheduled for arthroplasty, characterize their pain qualitatively and quantitatively and investigates whether differences exist in pain expression between younger and older patients, and between men and women.

METHODS

One hundred eight patients scheduled for a joint arthroplasty completed the Knee Injury and Osteoarthritis Outcome Score (KOOS) or Hip Disability and Osteoarthritis Outcome Score (HOOS) and a health-related quality of life question. Pain was assessed using the visual analogue scale (VAS), KOOS/HOOS and the Pain-o-Meter (POM) consisting of 12 sensory and 11 affective words (POM-Words). Frequency of analgesics use was assessed and preoperative radiographs were graded. ANOVA was used to test differences in pain expression with age (< 65 vs. ≥65 years), sex, and affected joint as independent factors.

RESULTS

Patients < 65 years of age used more affective words (POM) and words with higher affective intensity (median scores 8 (3-39), 5.5 (2-27) respectively), than older patients, despite having less radiographically advanced OA. They also reported more symptoms (KOOS/HOOS) than older patients. However, pain ratings, as measured by VAS and KOOS/HOOS pain, did not differ between younger and older adults. Women reported more frequent analgesics use (45.7 and 26.5% respectively) and rated their pain higher than men (mean POM-VAS = 42 (SD 24) and 31 (SD 19); respectively). No differences existed between sexes for sensory or affective POM-Words, or radiographic grade of OA. With age and sex as independent factors, a significant difference between knee and hip OA remained for sensory POM-words intensity scores.

CONCLUSIONS

Younger adults scheduled for arthroplasty expressed pain using more affective words and words with higher intensity and had less radiographically advanced OA than older adults. However, VAS and KOOS/HOOS pain subscales could not distinguish the difference in pain expression. Thus, the POM may be a valuable tool for assessment of pain.

Clinical characteristics and disability in patients with knee osteoarthritis: real world experience from Bulgaria

Objectives

Although knee osteoarthritis (KOA) is a leading cause of impaired functioning among older adults globally, little is still known about the complex mechanisms of disability accumulation in these patients. The aim of the study was to analyze the clinical parameters of patients with KOA in a Bulgarian population and to determine which of these clinical characteristics define disability to the greatest extent.

Material and methods

Patients aged 40–80 years with symptomatic KOA were included. The assessment tools for pain, clinical disease severity, and disability were the pain visual analogue scale (VAS) and disease-specific questionnaires: Algofunctional Index of Lequesne, Western Ontario and McMaster Universities OA Index (WOMAC), and the Health Assessment Questionnaire-Disability Index (HAQ-DI), respectively. Radiographs of the knees were obtained and graded according to the Kellgren-Lawrence (KL) system.

Results

One hundred and thirty-two patients (81% women) participated in the study. The median values of VAS (mm), WOMAC, Lequesne, and HAQ-DI scores were 52, 37.5, 11, 0.88, respectively. Men had milder disease, resulting in lower VAS, WOMAC, Lequesne, and HAQ-DI scores and less structural damage compared to women (p < 0.05). WOMAC index correlated positively with age of the patients but not with duration of the complaints. Patients with severe and very severe pain did not differ in their HAQ-DI, disease severity and KL grading. WOMAC physical function score and Lequesne index were independent predictors for the HAQ-DI in patients with KOA.

Conclusions

Bulgarian patients with KOA had moderate disability which showed a strong relationship with physical function of WOMAC and disease severity. Multiple layers of causality coexist to determine the knee pain in Bulgarian patients with KOA.

Efficacy of intraarticular corticosteroid hip injections for osteoarthritis and subsequent surgery

OBJECTIVE

Our study aimed to determine the duration of pain relief from intraarticular hip corticosteroid injections and identify patient predictive factors on injection response. We also sought to determine the subsequent rate of hip surgery and whether severity of hip osteoarthritis or injection response correlated with the decision to undergo surgery.

MATERIALS AND METHODS

All intraarticular hip steroid injections performed for osteoarthritis under fluoroscopic guidance at a single institution between January 2010 to December 2012 were retrospectively reviewed. Response was divided into three groups: no relief, immediate (≤ 2 weeks of pain relief), and continued (> 2 weeks of pain relief). Presence of hip surgery for osteoarthritis performed within 2 years following injection was obtained. Correlation between patient characteristics with injection outcome and hip surgery was analyzed.

RESULTS

Of 78 patients, a total of 82 injections were analyzed. For injections, 19.5% (16/82) showed no response, 47.6% (39/82) showed immediate response, and 32.9% (27/82) showed continued response. There was no significant correlation between injection outcome with age, Tönnis grade, BMI, or duration of symptoms. In total, 48.7% had hip surgery within 2 years after initial injection. There was a significant association between Tönnis grade and surgery, with higher Tönnis grades correlating with decision to undergo surgery (p = 0.002).

CONCLUSIONS

Gender, age, BMI, duration of symptoms, and radiographic severity of disease do not predict injection response. Due to high surgical rates and poor response, intraarticular hip steroid injections may be less effective in the long term, and surgical management may be considered earlier.

High preoperative serum leptin level is an independent risk factor for deep vein thrombosis after total knee arthroplasty in osteoarthritis patients: A prospective and cross-sectional study

It suggests that a high leptin level may increase the risk of venous thromboembolism (VTE) in animal studies. However, clinical studies in this field are still largely unexplored. Our objective was to evaluate the relationship between the preoperative serum leptin levels and postoperative VTE incidence in osteoarthritis (OA) patients who underwent total knee arthroplasty (TKA) at our institute.We conducted a prospective and cross-sectional study in these OA patients from March 2014 to March 2016. Preoperative leptin levels were analyzed by Luminex assays. VTE was assessed preoperatively and on postoperative day 5 and 7. The potential risk factors for VTE were also documented.We enrolled 203 OA patients. No PE was detected and DVT was diagnosed in 34 patients postoperatively. There were significant differences between the median leptin levels in DVT group and non-DVT group [25.13 ng/mL (interquartile range, 14.51-44.31) vs 18.71 ng/mL (8.26-28.99), P = .007]. The relative risk of DVT significantly increased with natural logarithm (ln) leptin (per SD increase) (OR 2.37, 95% confidence interval (95% CI), 1.29-4.33, P = .005). Multivariate analyses adjusted for potential confounders showed ln leptin (per SD increase) was significantly associated with the relative risk of DVT (OR 2.17, 95% CI, 1.01-4.64, P = .046). When patients were subdivided into tertiles according to their leptin values, the OR for DVT increased with increasing tertiles of serum leptin (OR 1.03, 95% CI, 1.01-1.06, P for trend = .023).In the present study, our results indicate that a high preoperative leptin level may be an independent risk factor for postoperative DVT.

Magnetic resonance imaging (MRI)-defined cartilage degeneration and joint pain are associated with poor physical function in knee osteoarthritis - the Oulu Knee Osteoarthritis study

OBJECTIVE

The main aim was to investigate the associations between Magnetic Resonance Imaging (MRI)-defined structural pathologies of the knee and physical function.

DESIGN

A cohort study with frequency matching on age and sex with eighty symptomatic subjects with knee pain and suspicion or diagnosis of knee osteoarthritis (OA) and 57 asymptomatic subjects was conducted. The subjects underwent knee MRI, and the severity of structural changes was graded by MRI Osteoarthritis Knee Score (MOAKS) in separate knee locations. WOMAC function subscores were recorded and physical function tests (20-m and 5-min walk, stair ascending and descending, timed up & go and repeated sit-to-stand tests) performed. The association between MRI-defined structural pathologies and physical function tests and WOMAC function subscores were evaluated by linear regression analysis with adjustment for demographic factors, other MRI-features and pain with using effect size (ES) as a measure of the magnitude of an association.

RESULTS

Cartilage degeneration showed significant association with poor physical performance in TUG-, stair ascending and descending-, 20-m- and 5-min walk-tests (ESs in the subjects with cartilage degeneration anywhere between 0.134 [95%CI 0.037-0.238] and 0.224 [0.013-0.335]) and with increased WOMAC function subscore (ES in the subjects with cartilage degeneration anywhere 0.088 [0.012-0.103]). Also, lateral meniscus maceration and extrusion were associated with poor performance in stair ascending test (ESs 0.067 [0.008-0.163] and 0.077 [0.012-0.177]).

CONCLUSIONS

After adjustments cartilage degeneration was associated with both decreased self-reported physical function and poor performance in the physical function tests. Furthermore, subjects with lateral meniscus maceration and extrusions showed significantly worse performance in stair ascending tests.

Pain in osteoarthritis. Implications for optimal management

Pain is an ubiquitous symptom in osteoarticular diseases, occurring much more commonly than stiffness or disability. OA of the knee, hand, or hip affects around 20% of adults in various populations and is dramatically increasing in many countries, mostly related to age and obesity, leading to an increased number of people having OA pain, and creating a huge burden related to disability and health care costs. OA-related pain, has been classically considered to be a nociceptive pain condition. Clinicians have considered pain to be an alarm signal, correlated to the intensity of joint degradation. In OA, most authors have focused their studies on joint architecture and local degradation, considering pain as only a symptom, a consequence of joint damage. However, OA-related pain is a specific disease, with a complex pathophysiology, including neuropathic peripheral and central abnormalities, together with local inflammation involving all joint structures. Clinical findings emphasize that it is not a stable and linear condition, that pain experience is independent of structural modifications, and that the quality of pain in OA is important to consider, aside from its intensity. OA-related pain is modulated by many factors, including the individual patient's psychological and genetic factors, as well as the theoretical role of meteorological influences. Recent neuroimaging findings have improved our knowledge about central mechanisms of OA pain, especially in persistent cases.

Synovial fluid pro-inflammatory profile differs according to the characteristics of knee pain

OBJECTIVE

The role of inflammation and pain in osteoarthritis (OA) is not fully understood. We evaluated the association between pro-inflammatory biomarkers and pain.

METHODS

We used baseline data and samples from a randomized controlled trial of colchicine for symptomatic knee OA. Severity of pain of the more symptomatic knee was assessed by National Health and Nutrition Examination Survey-I (NHANES-I) criterion and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) pain index. Pains on movement and at rest were self-reported on an 11-point Likert scale. Severity of radiographic tibiofemoral OA was assessed by Kellgren and Lawrence (KL) grade. Concentrations of synovial fluid (sf) IL-1β, IL-6, IL-8, TNFα, C-terminal telopeptides of Type I collagen (CTXI) and C-telopeptide of Type II collagen (CTXII), as well as urinary (u) CTXII were measured.

RESULTS

Of the 109 patients enrolled in the study, 70 patients (70% women) with synovial fluid obtained by direct aspiration were included for analysis. The mean ± SD age and body mass index (BMI) of the patients were 57.6 ± 8.3 years and 28.8 ± 5.2 kg/m². After adjustment for age, sex, and BMI, sf IL-6 and IL-8 were statistically significantly associated with 11-point pain on movement, but not with pain at rest. No significant associations were observed with WOMAC pain scores. sf IL-1β (analyzed as detectable/non-detectable) was inversely associated with pain. In contrast, after adjustment, Sf TNFα was associated with WOMAC total pain and both pain on movement and at rest. sf/u CTXII was associated with radiographic severity, but not with knee pain.

CONCLUSIONS

This study provides indication that OA pain mechanisms may differ according to the characteristics of the pain.

Multimodal analgesia in moderate-to-severe pain: a role for a new fixed combination of dexketoprofen and tramadol

BACKGROUND

Untreated and under-treated pain represent one of the most pervasive health problems, which is worsening as the population ages and accrues risk for pain. Multiple treatment options are available, most of which have one mechanism of action, and cannot be prescribed at unlimited doses due to the ceiling of efficacy and/or safety concerns. Another limitation of single-agent analgesia is that, in general, pain is due to multiple causes. Combining drugs from different classes, with different and complementary mechanism(s) of action, provides a better opportunity for effective analgesia at reduced doses of individual agents. Therefore, there is a potential reduction of adverse events, often dose-related. Analgesic combinations are recommended by several organizations and are used in clinical practice. Provided the two agents are combined in a fixed-dose ratio, the resulting medication may offer advantages over extemporaneous combinations.

CONCLUSIONS

Dexketoprofen/tramadol (25 mg/75 mg) is a new oral fixed-dose combination offering a comprehensive multimodal approach to moderate-to-severe acute pain that encompasses central analgesic action, peripheral analgesic effect and anti-inflammatory activity, together with a good tolerability profile. The analgesic efficacy of dexketoprofen/tramadol combination is complemented by a favorable pharmacokinetic and pharmacodynamic profile, characterized by rapid onset and long duration of action. This has been well documented in both somatic- and visceral-pain human models. This review discusses the available clinical evidence and the future possible applications of dexketoprofen/tramadol fixed-dose combination that may play an important role in the management of moderate-to-severe acute pain.

Rest Pain and Movement-Evoked Pain as Unique Constructs in Hip and Knee Replacements

Objective

There is limited information about the extent to which the association between preoperative and chronic postoperative pain is mediated via pain‐on‐movement or pain‐at‐rest. We explored these associations in patients undergoing total hip replacement (THR) and total knee replacement (TKR).

Methods

A total of 322 and 316 patients receiving THR and TKR, respectively, were recruited into a single‐center UK cohort (Arthroplasty Pain Experience) study. Preoperative, acute postoperative, and 12‐month pain severity was measured using self‐reported pain instruments. The association between preoperative/acute pain and chronic postoperative pain was investigated using structural equation modeling (SEM).

Results

Patients with high levels of preoperative pain were more likely to report chronic pain after THR (β = 0.195, P = 0.02) and TKR (β = 0.749, P < 0.0001). Acute postoperative pain‐on‐movement was not associated with chronic pain after TKR or THR after adjusting for preoperative pain; however, acute pain‐at‐rest was associated with chronic pain after THR (β = 0.20, P < 0.0002) but not TKR after adjusting for preoperative pain. Analysis of pain‐at‐rest and pain‐on‐movement highlighted differences between THR and TKR patients. Chronic pain‐at‐rest after THR was weakly associated with pain‐at‐rest during the preoperative (β = 0.11, P = 0.068) and acute postoperative period (β = 0.21, P < 0.0001). In contrast, chronic pain‐on‐movement after TKR was strongly associated with the severity of pain‐on‐movement during the preoperative period (β = 0.51, P = 0.001).

Conclusion

SEM illustrated the different patterns of association between measures of pain over time in patients undergoing THR and TKR for osteoarthritis. These findings highlight the importance of future work that explores the mechanisms underlying pain‐on‐movement and pain‐at‐rest.

Pain among older adults from a gender perspective: findings from the Swedish National Study on Aging and Care (SNAC-Blekinge)

BACKGROUND AND AIMS

Pain is common in the elderly population and its prevalence varies according to the studied disease, clinical setting, sex and age. This study examines pain in an aging population from a gender perspective.

METHODS

The Swedish National study on Aging and Care (SNAC) is conducted at four research centres. Participants were recruited from the baseline sample (n=1402) at one of the research centres, SNAC-Blekinge. Individuals aged 60 years and older were included and non-participation was documented. Research personnel conducted the medical examination on two occasions.

RESULTS

The prevalence of pain was 769/1402 (54.8%), distributed as 496/817 (64.5%) women and 273/585 (35.5%) men,p<0.01. Women reported more pain located in the vertebral column,p<0.01. The most common pain location was the legs and feet. About 84% reported pain intensity as 4 or higher on the visual analogue scale (VAS). Pain intensity declines with age among men,p<0.01. The most frequent treatment was painkillers. A total of 128/263 (48.7%) of the men received no pain treatment compared with 177/478 (37.0%) of the women,p<0.01. In a multivariate logistic regression model, women yielded the highest OR [OR 1.94 (C.I. 1.51-2.49)] for pain.

CONCLUSIONS

Pain is common among older adults and there are significant differences between the sexes. Almost 55% of participants reported pain, predominantly women. In the majority of cases the intensity was rated as moderate or severe (VAS >4) and women rated higher than men p<002. Almost half of the men (48.7%) did not receive any treatment compared to 37% of the women, p<001.

Longitudinal (4 year) change of thigh muscle and adipose tissue distribution in chronically painful vs painless knees--data from the Osteoarthritis Initiative

OBJECTIVE

To evaluate 4-year longitudinal change in thigh muscle and adipose tissue content in chronically painful vs painless knees.

METHODS

Knees from Osteoarthritis Initiative (OAI) participants with non-acceptable symptom status (numerical rating scale (NRS) ≥4) and frequent pain (≥6 months at baseline, year 2 and year 4 follow-up) were studied. These were matched with painless controls (bilateral NRS pain intensity ≤1 and ≤infrequent pain at all 3 timepoints). 4-year longitudinal changes in thigh muscle anatomical cross-sectional areas (CSAs), isometric muscle strength, and in subcutaneous (SCF) and intermuscular fat (IMF) CSAs were obtained from magnetic resonance images (MRI) and were compared between groups (paired t-tests).

RESULTS

43 participants fulfilled the inclusion criteria of chronic pain, had complete thigh muscle MRI acquisitions and strength measurements, and a matched control. Quadriceps CSAs, but not extensor strength, showed a significant longitudinal decrease in chronically painful knees (-3.9%; 95% confidence interval [95 CI] -6.3%, -1.5%) and in painless controls (-2.4%; 95% CI -4.1%, -0.7%); the difference in change was not statistically significant (P = 0.33). There was a significant 4-year gain in SCF in painful knees (8.1%; 95% CI 3.1%, 13%) but not in controls (0.0%; 95% CI -4.4%, +4.4%) with the difference in change being significant (P = 0.03). The gain in IMF (∼5.2%) was similar between painful and painless knees.

CONCLUSION

This is the first paper to show a significant impact of (chronic) knee pain on longitudinal change in local subcutaneous adipose tissue. The effect of pain on subcutaneous fat appeared stronger than that on intermuscular adipose tissue and on muscle status.

Osteoarthritis pain

Osteoarthritis (OA) represents one of the most frequently occurring painful conditions. Pain is the major OA symptom, involving both peripheral and central neurological mechanisms. OA pain is initiated from free axonal endings located in the synovium, periosteum bone, and tendons, but not in the cartilage. The nociceptive message involves not only neuromediators and regulating factors such as neuronal growth factor (NGF) but also central modifications of pain pathways. OA pain is a mixed phenomenon where nociceptive and neuropathic mechanisms are involved in both the local and central levels. OA pain perception is influenced by multiple environmental, psychological, or constitutional factors, and OA pain intensity is not correlated with joint degradation. OA pain may present with different clinical features: constant and intermittent pain, with or without a neuropathic component, and with or without central sensitization. Finally, OA pain should be considered as a complex and not unique pain condition, where precise clinical assessment may drive specific therapeutic approaches.

Contralateral knee effect on self-reported knee-specific function and global functional assessment: data from the Osteoarthritis Initiative

OBJECTIVE

To analyze the effect of contralateral knee pain on sensitivity of patient-reported outcomes and objectively measured functional performance tests in subjects with knee osteoarthritis (OA).

METHODS

Subjects with discordant knee pain status (i.e., 1 knee being painful [≥4 on a numeric pain rating scale (NPRS)], with the contralateral knee being pain free [NPRS 0]) were selected from the Osteoarthritis Initiative and matched to subjects with bilaterally pain-free and painful knees by age, sex, body mass index, and radiographic knee OA. The Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) physical function score, the global Physical Activity Scale for the Elderly (PASE), and objective functional performance tests were cross-sectionally compared in a matched case-control design.

RESULTS

A total of 378 subjects with discordant knee pain status were matched to 359 controls with bilaterally pain-free knees and to 323 controls with bilaterally painful knees. WOMAC scores in pain-free knees of discordant knee pain cases significantly differed compared to scores of bilaterally pain-free knees (P = 0.003). Likewise, scores in painful knees of discordant knee pain cases significantly differed compared to scores of bilaterally painful knees (P < 0.001). PASE levels between these groups were not significantly different (P > 0.68). Functional performance tests differed in subjects with discordant knee pain compared to subjects with bilaterally pain-free knees and when compared to subjects with bilaterally painful knees, with the chair stand test showing the strongest effect size (standardized response mean 0.28 and 0.33, respectively).

CONCLUSION

The WOMAC physical function score, although knee specific, is impacted by the contralateral knee pain status. The repeated chair stand test appears to be the most sensitive assessment in differentiation between groups with different status of knee pain.

Long-term persistence of knee pain and occupational exposure in two large prospective cohorts of workers

Background

The persistence of knee pain (KP) and its relationship with occupational factors were investigated in two prospective cohorts of French workers: retirees of the Gazel cohort and workers in the Cosali cohort.

Methods

KP was defined according to the Nordic questionnaire (>1 day in the last year), and the information was extracted from two questionnaires in 2006 and 2012 for the Gazel cohort, and in 2002–2005 and 2007–2010 for the Cosali cohort. The personal and occupational factors and the severity of KP were measured at baseline. Of the 4590 members of the Gazel cohort with KP at baseline, 4140(90.2%) were followed up, as were 637(63.1%) members of the Cosali cohort. Logistic models were used to evaluate associations (ORs) between occupational exposure and the persistence of KP separately by sex, adjusted on indicators of severity of KP.

Results

KP was no longer present at follow-up for 38.3% of Gazel men and 46.0% of Cosali men (33.4% of Gazel women and 50.6% of Cosali women). The persistence of KP in men was associated with carrying or handling heavy loads on univariate analyses and with kneeling on multivariate analyses, with ORs of 1.3(1.0-1.6) (Gazel) and 1.6(1.0-2.6) (Cosali). Climbing stairs was not significantly associated with the persistence of knee pain among men. The persistence of KP in women was not significantly associated with such occupational exposure.

Conclusions

This study highlights the role of occupational factors in the persistence of KP for men, in particular kneeling and handling/carrying loads.

Electronic supplementary material

The online version of this article (doi:10.1186/1471-2474-15-411) contains supplementary material, which is available to authorized users.

The avoidance model in knee and hip osteoarthritis: a systematic review of the evidence

The avoidance model in patients with knee and hip osteoarthritis (OA) hypothesizes that pain and psychological distress lead to avoidance of activities, and thereby to muscle weakness and activity limitations. This paper systematically reviews the scientific evidence for the validity of this avoidance model. A qualitative data synthesis was used to identify levels of evidence. Sixty studies were included. In knee OA, strong evidence was found that avoidance of activities is associated with activity limitations via muscle weakness (mediation by muscle weakness), strong evidence was found for an association between muscle weakness and activity limitations, and weak evidence was found that pain and psychological distress are associated with muscle weakness via avoidance of activities (mediation by avoidance). In hip OA, weak evidence was found for mediation by muscle weakness; and strong evidence was found for an association between muscle weakness and activity limitations. More research is needed on the consecutive associations between pain or psychological distress, avoidance of activities and muscle weakness, and to confirm causal relationships.

"Let's talk about OA pain": a qualitative analysis of the perceptions of people suffering from OA. Towards the development of a specific pain OA-Related questionnaire, the Osteoarthritis Symptom Inventory Scale (OASIS)

INTRODUCTION

Pain is the primary outcome measurement in osteoarthritis, and its assessment is mostly based on its intensity. The management of this difficult chronic condition could be improved by using pain descriptors to improve analyses of painful sensations. This should help to define subgroups of patients based on pain phenotype, for more adapted treatment. This study draws upon patients' descriptions of their pain, to identify and understand their perception of osteoarthritis pain and to categorize pain dimensions.

METHODS

This qualitative study was conducted with representative types of patients suffering from osteoarthritis. Two focus groups were conducted with a sample of 14 participants, with either recent or chronic OA, at one or multiple sites. Focus groups were semi-structured and used open-ended questions addressing personal experiences to explore the experiences of patients with OA pain and the meanings they attributed to these pains.

RESULTS

TWO MAIN POINTS EMERGED FROM CONTENT ANALYSES: -A major difficulty in getting patients to describe their osteoarthritis pain: perception that nobody wants to hear about it; necessity to preserve one's self and social image; notion of self-imposed stoicism; and perception of osteoarthritis as a complex, changing, illogical disease associated with aging. -Osteoarthritis pains were numerous and differed in intensity, duration, depth, type of occurrence, impact and rhythm, but also in painful sensations and associated symptoms. Based on analyses of the verbatim interviews, seven dimensions of OA pain emerged: pain sensory description, OA-related symptoms, pain variability profile, pain-triggering factors, pain and physical activity, mood and image, general physical symptoms.

SUMMARY

In osteoarthritis, pain analysis should not be restricted to intensity. Our qualitative study identified pain descriptors and defined seven dimensions of osteoarthritis pain. Based on these dimensions, we aim to develop a specific questionnaire on osteoarthritis pain quality for osteoarthritis pain phenotyping: the OsteoArthritis Symptom Inventory Scale (OASIS).

Unilateral vs bilateral symptomatic knee osteoarthritis: associations between pain intensity and function

OBJECTIVE

The objective of this study was to determine if associations between pain distribution (unilateral vs bilateral) and measures of function (self-report vs performance-based) were influenced by knee pain intensity of the painful knee(s) in persons with moderate to severe symptomatic knee OA.

METHODS

Data from persons in the Osteoarthritis Initiative (OAI) dataset (n = 852) with symptomatic knee OA were studied. Key dependent variables were the WOMAC physical function, Knee Injury and Osteoarthritis Outcome Score (KOOS) quality of life, the repeated chair stand test and the 20-m walk test. In addition to covariates, the independent variables were the presence of unilateral or bilateral OA involvement (either Kellgren and Lawrence grade 3 or 4 or a grade <3) and pain category (mild, moderate or severe).

RESULTS

WOMAC physical function scores consistently showed the strongest association with pain intensity for persons with unilateral vs bilateral knee pain. For example, in persons with unilateral severe knee pain, WOMAC scores averaged 19.9 (S.D. = 12.0) points while persons with bilateral knee pain with at least one knee rated as severe had WOMAC scores ranging from 25.3 to 28.9, depending on pain severity of the contralateral knee. These differences were statistically significant (P < 0.001) as was the test for trend (P = 0.001). Self-report measures generally showed larger effect sizes than performance-based measures.

CONCLUSION

Knee pain intensity influences self-report and performance-based tests differently depending on whether knee pain is unilateral or bilateral. WOMAC scores are most strongly associated with pain intensity in persons with unilateral vs bilateral pain while walking tests are least influenced by pain intensity.

Obesity and increased burden of hip and knee joint disease in Australia: results from a national survey

BACKGROUND

Research involving more representative samples is needed to extend our understanding of the broader impact of obesity in hip or knee joint disease (arthritis and OA) beyond clinical settings. Although population-based research has been conducted in the United States, how these findings translate to other countries is unclear. Using a national approach, this study explored associations between obesity and the burden of hip and knee joint disease in Australia (in terms of prevalence, pain, stiffness, function, Health-Related Quality of Life (HRQoL) and disease severity).

METHODS

A random sample of 5000 Australians (≥ 39 years) from the federal electoral roll was invited to complete a mailed questionnaire to identify doctor-diagnosed hip arthritis, hip OA, knee arthritis and knee OA and evaluate the burden of these conditions. Validated questionnaires included the WOMAC Index, Assessment of Quality of Life instrument and Multi-Attribute Prioritisation Tool. Body Mass Index (BMI) was classified into underweight/normal weight (≤ 24.99 kg/m2), overweight (25-29.99) or obese (≥ 30). Multiple logistic regression was used to estimate odds of arthritis and OA, with demographic and socioeconomic variables included in the models. Associations between BMI and other variables were investigated using analysis of covariance, with adjustment for age and sex.

RESULTS

Data were available from 1,157 participants (23%). Overweight participants had increased odds of knee arthritis (adjusted OR (AOR) 1.87, 95%CI 1.14-3.07) and knee OA (AOR 2.11, 95%CI 1.07-4.15). Obesity was associated with higher prevalence of hip arthritis (AOR 2.18, 95%CI 1.17-4.06), knee arthritis (AOR 5.47, 95%CI 3.35-8.95) and knee OA (AOR 7.35, 95%CI 3.85-14.02). Of those with arthritis or OA, obese individuals reported more pain (for hip arthritis, hip OA and knee OA), greater stiffness (for hip arthritis, knee arthritis and knee OA), worse function (all diagnoses), lower HRQoL (for hip arthritis and hip OA) and greater disease severity (all diagnoses).

CONCLUSIONS

This national study has demonstrated that the odds of arthritis and OA was up to 7 times higher for obese individuals, compared with those classified as underweight/normal weight. Concurrent obesity and joint disease had a marked impact on several key aspects of wellbeing, highlighting the need for public health interventions.

Gender-specific correlates of complementary and alternative medicine use for knee osteoarthritis

BACKGROUND

Knee osteoarthritis (OA) increases healthcare use and cost. Women have higher pain and lower quality of life measures compared to men even after accounting for differences in age, body mass index (BMI), and radiographic OA severity. Our objective was to describe gender-specific correlates of complementary and alternative medicine (CAM) use among persons with radiographically confirmed knee OA.

METHODS

Using data from the Osteoarthritis Initiative, 2,679 women and men with radiographic tibiofemoral OA in at least one knee were identified. Treatment approaches were classified as current CAM therapy (alternative medical systems, mind-body interventions, manipulation and body-based methods, energy therapies, and three types of biologically based therapies) or conventional medication use (over-the-counter or prescription). Gender-specific multivariable logistic regression models identified sociodemographic and clinical/functional correlates of CAM use.

RESULTS

CAM use, either alone (23.9% women, 21.9% men) or with conventional medications (27.3% women, 19.0% men), was common. Glucosamine use (27.2% women, 28.2% men) and chondroitin sulfate use (24.8% women; 25.7% men) did not differ by gender. Compared to men, women were more likely to report use of mind-body interventions (14.1% vs. 5.7%), topical agents (16.1% vs. 9.5%), and concurrent CAM strategies (18.0% vs. 9.9%). Higher quality of life measures and physical function indices in women were inversely associated with any therapy, and higher pain scores were positively associated with conventional medication use. History of hip replacement was a strong correlate of conventional medication use in women but not in men.

CONCLUSIONS

Women were more likely than men to use CAM alone or concomitantly with conventional medications.

The impact of digit-related radiographic osteoarthritis of the hand on grip-strength and upper extremity disability

BACKGROUND

Interpreting the impact of hand osteoarthritis (OA) on hand function is complicated owing to the multiple digits and joints in the hand.

QUESTIONS/PURPOSE

We determined the impact of digit-related radiographic OA on hand function in patients 65 years or older.

METHODS

We evaluated hand radiographs in 196 men and 182 women older than 65 years without shoulder or elbow pain who participated in the Korean Longitudinal Study on Health and Aging. Using the Kellgren and Lawrence criteria, we graded the 15 joints in each hand from 0 to 4 for OA, and evaluated hand function by measuring DASH scores and grip and pinch strength of dominant hands. We performed multiple linear regression analyses to evaluate associations between hand functions and the sum of Kellgren and Lawrence grade of each digit.

RESULTS

The sums of Kellgren and Lawrence grades for thumbs and middle fingers were independently associated with grip strength, and the sums of the Kellgren and Lawrence grades for thumbs and index fingers were independently associated with pinch strength after controlling for age and sex. DASH scores were independently associated with OA of the thumb, or index or middle finger, but not with OA of the ring or small finger.

CONCLUSIONS

This study revealed cumulative effects of joint involvement and Kellgren and Lawrence grades of thumb and middle finger OA on grip strength, and thumb and index finger OA on pinch strength. Furthermore, OA of either of three radial digits was associated with more severe upper extremity disabilities.

LEVEL OF EVIDENCE

Level IV, diagnostic study. See Guidelines for Authors for a complete description of levels of evidence.

Biomechanical influence of cartilage homeostasis in health and disease

There is an urgent demand for long term solutions to improve osteoarthritis treatments in the ageing population. There are drugs that control the pain but none that stop the progression of the disease in a safe and efficient way. Increased intervention efforts, augmented by early diagnosis and integrated biophysical therapies are therefore needed. Unfortunately, progress has been hampered due to the wide variety of experimental models which examine the effect of mechanical stimuli and inflammatory mediators on signal transduction pathways. Our understanding of the early mechanopathophysiology is poor, particularly the way in which mechanical stimuli influences cell function and regulates matrix synthesis. This makes it difficult to identify reliable targets and design new therapies. In addition, the effect of mechanical loading on matrix turnover is dependent on the nature of the mechanical stimulus. Accumulating evidence suggests that moderate mechanical loading helps to maintain cartilage integrity with a low turnover of matrix constituents. In contrast, nonphysiological mechanical signals are associated with increased cartilage damage and degenerative changes. This review will discuss the pathways regulated by compressive loading regimes and inflammatory signals in animal and in vitro 3D models. Identification of the chondroprotective pathways will reveal novel targets for osteoarthritis treatments.

Pharmacologic treatment of knee osteoarthritis in athletic women

There is a greater incidence of anterior cruciate ligament tears due to noncontact sports injuries in women compared with men. Anterior cruciate ligament tears are associated with accelerated development of knee osteoarthritis (OA), which is also more prevalent in women than in men. This article considers therapeutic modalities that are best suited for athletic women with knee OA. Clinical data on the safety and efficacy of pharmacotherapies for knee OA, including acetaminophen, oral nonsteroidal anti-inflammatory drugs (NSAIDs), and topical NSAIDs, are discussed, with attention paid to special considerations for women who participate in athletic activity. Adverse events associated with the use of acetaminophen and oral NSAIDs place potential limits on the dose and duration of therapy and may be of greater concern in female athletes than in other patient groups. Topical NSAIDs, which effect relief through the same mechanism of action as oral NSAIDs, produce dramatically lower systemic NSAID exposure compared with oral NSAIDs and are associated with a lower incidence of systemic adverse events. These findings, along with additional future studies, may have particular relevance to the choice of the most effective treatment options for athletic women with OA of the knee.

Pain, disability, and depression in osteoarthritis: effects of race and sex

OBJECTIVES

A cross-sectional study examined how race and sex affect associations among osteoarthritis (OA) pain, disability, and depression in 363 older adults with diagnosed knee OA.

METHOD

African American (Black; N = 94) and non-Hispanic White (White; N = 269) men and women self-reported pain, disability, depressive symptoms, arthritis history, general health, and demographic information.

RESULTS

Women experienced greater pain and marginally greater disability than men; African Americans reported greater disability and marginally greater pain than non-Hispanic Whites. These effects varied with education, health, and arthritis history. In ordinary least squares regression analyses, race and pain independently predicted depression. Significant interactions of race, sex, and disability were driven by a lack of relationship between depression and disability among African American men.

DISCUSSION

Race and sex influence affective response to OA pain and disability in complex ways, with African American men showing paradoxical effects. Further research is needed to elucidate mechanisms of this moderation effect.

Strength training alone, exercise therapy alone, and exercise therapy with passive manual mobilisation each reduce pain and disability in people with knee osteoarthritis: a systematic review

QUESTION

What are the effects of strength training alone, exercise therapy alone, and exercise with additional passive manual mobilisation on pain and function in people with knee osteoarthritis compared to control? What are the effects of these interventions relative to each other?

DESIGN

A meta-analysis of randomised controlled trials.

PARTICIPANTS

Adults with osteoarthritis of the knee. INTERVENTION TYPES: Strength training alone, exercise therapy alone (combination of strength training with active range of motion exercises and aerobic activity), or exercise with additional passive manual mobilisation, versus any non-exercise control. Comparisons between the three interventions were also sought.

OUTCOME MEASURES

The primary outcome measures were pain and physical function.

RESULTS

12 trials compared one of the interventions against control. The effect size on pain was 0.38 (95% CI 0.23 to 0.54) for strength training, 0.34 (95% CI 0.19 to 0.49) for exercise, and 0.69 (95% CI 0.42 to 0.96) for exercise plus manual mobilisation. Each intervention also improved physical function significantly. No randomised comparisons of the three interventions were identified. However, meta-regression indicated that exercise plus manual mobilisations improved pain significantly more than exercise alone (p = 0.03). The remaining comparisons between the three interventions for pain and physical function were not significant.

CONCLUSION

Exercise therapy plus manual mobilisation showed a moderate effect size on pain compared to the small effect sizes for strength training or exercise therapy alone. To achieve better pain relief in patients with knee osteoarthritis physiotherapists or manual therapists might consider adding manual mobilisation to optimise supervised active exercise programs.

Knee pain prevalence and associated factors in a Brazilian population study

OBJECTIVES

To estimate the association among knee pain and central obesity.

METHODS

A cross-sectional study was carried out in Salvador, Brazil, with a sample of 2,297 individuals ≥20 years of age. A standardized questionnaire was applied at home to collect data about pain, sociodemographic characteristics and abdominal circumference measurement. Unadjusted (bivariate analysis) and adjusted odds ratio (OR) and 95%CI were estimated by using backward stepwise logistic regression.

RESULTS

The prevalence of knee pain was found in 11.2% of the studied sample. Unadjusted OR associations (P<0.1) were found for male (OR 2.70, CI [confidence interval] 2.01-3.63), older age (OR 2.98, CI 1.89-4.42), and obesity (OR 1.62, CI 1.22-2.15). Adjusted ORs (P<0.05) were found for obesity-married individuals (OR 4.69, CI 1.09-20.11), separated (OR 11.03, CI 2.09-58.20) or widowed (OR 7.17, CI 1.40-36.61), and male (OR 2.35, CI 1.25-4.41). The OR of nonobese men was 2.66, CI 1.74-4.06, but being married seems to protect them of knee pain (OR 0.66, CI 0.45-0.96).

CONCLUSION

In this study, we found a knee pain prevalence of 11.2% and positive association with the male gender, married, separated or widowed, and a protective association for knee pain in nonobese married male. Aging, obesity, and excessive alcohol consumption were independent correlates of knee pain in the studied population sample.

Is level of pain acceptance differentially related to social cognitions and behavior? The case of active women with arthritis

Pain from arthritis is a barrier to physical activity (PA), yet some people still manage to be active. This study examined whether women with greater or weaker arthritis pain acceptance were distinguished by social cognitions (self-regulatory efficacy to overcome barriers; outcome expectations of PA) and whether PA differences existed. Women with arthritis (N = 118) completed two surveys. After controlling for pain, a hierarchical discriminant function analysis discriminated pain acceptance groups in terms of the social cognitions. Greater pain acceptance participants were also significantly more active. Findings contribute new insight on the combination of a disease-related factor (pain acceptance) and social cognitions important for adherence.