Squatting, sitting on the floor, or cycling: Are life-long daily activities risk factors for clinical knee osteoarthritis? Stage III results of a community-based study

Correlation of knee laxity with alignment and repetitive physical activity in patients with knee osteoarthritis: A cross-sectional study

BACKGROUND

Malalignment, knee laxity, and repetitive physical activity are considered biomechanical risk factors for knee osteoarthritis (KOA), though the correlation among these factors is poorly understood. The purpose of this study was to elucidate the relationship between knee laxity and alignment, and to determine the effects of repetitive physical activity on knee laxity in patients with KOA.

METHODS

The study subjects were 68 patients with radiographic tibiofemoral KOA and 68 control subjects. Each participant underwent clinical evaluation, muscle strength test, radiography, and knee laxity test. Laxity was evaluated before and after repetitive stepping exercise using tri-axial accelerometer.

RESULTS

Mediolateral acceleration correlated (P < 0.01) with two coronal alignments (mechanical axis: hip-knee-ankle angle (HKA); and joint line convergent angle (JLCA)). Pearson correlation coefficient was small (r = 0.23-0.24) before but increased after stepping (r = 0.28-0.33). Increased mediolateral acceleration after stepping correlated with JLCA (r = 0.37, P < 0.001). There were significant differences in coronal alignments, gait speed, mediolateral acceleration, and accelerations in all directions between the control and KOA groups. Anteroposterior acceleration did not correlate with sagittal knee alignment. Multiple logistic regression analysis identified HKA/JLCA, and increased mediolateral acceleration after stepping as significant diagnostic predictors of KOA.

CONCLUSIONS

We found a direct relationship between knee laxity and alignment or repetitive physical activity. Repetitive stepping activity significantly increased mediolateral acceleration in KOA patients, compared with the control. Stepping increased the correlation between mediolateral acceleration and coronal alignment. In knees with large JLCA, repetitive stepping caused much larger mediolateral laxity.

Osteoarthritis Risks and Sports: An Evidence-based Systematic Review

PURPOSE

Regular sports activities are associated with multiple physical and psychological health benefits. However, sports also may lead to injuries and the development of osteoarthritis (OA). This systematic review investigated the association between sports activity, sports type, and the risk of developing OA.

METHODS

A systematic review was performed by assessing studies that have investigated the risk of OA development in sports. Data extracted included general information, study design, number of participants, related body mass index, sports type, and assessment of OA. The methodological quality of the studies was assessed using the Newcastle-Ottawa Scale.

RESULTS

A total of 63 studies were included in this systematic review. The overall Newcastle-Ottawa Scale score was 6.46±1.44 demonstrating a good methodological quality of the articles included in the present study. A total of 628,036 participants were included, with a mean follow-up of 8.0±8.4 years. The mean age of the included athletes was 45.6±15.8, with a mean body mass index of 24.9±2.3 kg/m 2 .

CONCLUSION

Football and soccer players seem to be at higher risk for the development of OA, although the injury status of the joint should be considered when assessing the risk of OA. High equipment weight and increased injury risk also put military personnel at a higher risk of OA, although elite dancing leads to more hip labral tears. Femoroacetabular impingement was also often diagnosed in ice-hockey players and ballet dancers.

The Influence of Athletes' Age in the Onset of Osteoarthritis: A Systematic Review

PURPOSE

Whether sport participation is a risk factor for osteoarthritis (OA) development or progression is controversial. Mechanical overload, injuries, genetics, and acquired disorders concur to the onset of OA, with high variability between sports and participants. This study investigated the association between participation in specific sports and the risk of developing knee and hip OA in athletes at different ages. We hypothesized that young athletes who are exposed to high levels of physical activities have a greater risk of developing OA.

MATERIALS AND METHODS

This systematic review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. PubMed, Google scholar, EMABSE, and Web of Science were accessed in October 2021. No time constrains were used for the search. All the published clinical studies reporting data about relationship between physical activity, OA, and age were included.

RESULTS

The Newcastle-Ottawa Scale resulted in a final score ≥7 for all studies, attesting good quality of the methodological assessment. Data from 27,364 patients were retrieved. The mean age was 48.2±16.7 years. In all, 21.8% were women.

CONCLUSIONS

Our systematic review suggests an association between high levels of physical activities and knee and hip OA in men younger than 50 years. People who practice intense physical activity, such as professional athletes or heavy workers, are more prone to develop early-onset OA.

Intensive Physical Activity Increases the Risk of Knee and Hip Arthroplasty: A Systematic Review

PURPOSE

The present study investigated the type of sport and activity level of athletes before they underwent knee and/or hip arthroplasty for osteoarthritis (OA), and compared them with a control group of subjects who did not undergo knee and hip arthroplasty. We hypothesed athletes exposed to high physical loads during sports had the highest risk of developing OA requiring arthroplasty.

MATERIALS AND METHODS

This systematic review was conducted according to the PRISMA guidelines. All the comparative clinical trials to August 2021 investigating the sport activity level between subjects who underwent arthroplasty versus those who did not undergo arthroplasty for OA were considered.

RESULTS

Data from 5 studies and 3638 patients were collected. The mean age for both groups was 47.61±15.5 years, and the mean body mass index was 24.6±2.1 kg/m2 17.6% were women. The Newcastle-Ottawa scale attested good quality of the methodology of the investigations included in the present study.

CONCLUSION

Intense physical exercise, implying a high cumulative number of hours of exercise which can lead to excessive joint overload, in both sexes is associated with greater likelihood of early knee and hip OA which may lead to prosthetic surgery. Moderate and recreational exposure to sport has minor degenerative effects, and is not associated with early onset OA requiring arthroplasty.

The Survey of Knee Osteoarthritis in the Population over Age 50 Visited in the Health Bus in Kermanshah, Iran

Along with an aging population worldwide, knee osteoarthritis (KOA), which is the main cause of musculoskeletal pain and disability in the elderly and decreases the quality of life, is prevalent, and their impact is widespread. This study aimed to evaluate the knee osteoarthritis status among the population over age 50 in Kermanshah, Iran. The research community consisted of the population who has been visited in the health bus in Kermanshah in 2016-2017, of which 589 were chosen by an available sampling method. A WOMAC questionnaire was used to determine the prevalence of knee osteoarthritis. The prevalence of knee stiffness rate after sitting, lying down, or resting during the day among women and men were 40.7% and 20.5%, respectively. According to the findings, the highest prevalence rate of knee pain was in subjects with a BMI higher than 30 (31.6%) and BMI 25–30 (24.5%). 39.2% of the subjects never experienced knee pain, 16.6% monthly, 13.4% once a week, 20.4% daily, and 10.4% of them had prolonged knee pain experience. The prevalence of gender-based knee pain was 60.5% among women and 38.6% among men. 30.5% of women and 61.4% of men never experienced knee pain.

Xanthohumol suppresses inflammation in chondrocytes and ameliorates osteoarthritis in mice

Osteoarthritis (OA), manifested as degeneration and damage of the articular cartilage is a progressive disease of joints. Previous studies have shown that extracellular matrix degradation and inflammation have quite a significant performance in the occurrence and development of OA. In various maladies, an anti-inflammatory effect has been demonstrated for Xanthohumol (XN); while OA is an inflammation related disease. The current in vivo and in vitro study aimed to investigate the therapeutic effect of XN on OA as well as its working mechanism. The results showed that XN has the capability to hinder the expression of nitric oxide synthase (INOS), IL-1β-promoted inducible nitric oxide (NO), necrosis factor-α of tumor (TNF-α), interleukin-6 (IL-6), and cyclooxygenase-2 (COX-2) in vitro. In addition, XN has been found to down-regulate the expression of matrix metalloproteinase-13 and prothrombin stimulated by IL-1β and up-regulates type II collagen and Aggrecan expression. At the same time, it was discovered that XN activates nuclear factor (Nrf2) in chondrocytes stimulated by IL-1β and inhibits nuclear factor B (NF-кB) signal transduction. The DMM model manifests that XN has an inhibitory impact on the progression of osteoarthritis and thus may be a candidate drug to slow down and delay the development of OA.

The Risk of Knee Osteoarthritis in Professional Soccer Players

BACKGROUND

We address the question whether professional soccer players with and without macroinjury of the knee joint are at an elevated risk for knee osteoarthritis.

METHODS

A systematic review with meta-analyses was conducted. The study protocol was prospectively registered (registration number CRD42019137139). The MEDLINE, EMBASE, and Web of Science databases were searched for relevant publications; in addition, forward searching was performed, and the listed references were considered. All steps of the process were undertaken independently by two reviewers, and any discordances were resolved by consensus. For all publications whose full text was included, the methods used were critically evaluated. The quality of the evidence was judged using the GRADE criteria.

RESULTS

The pooled odds ratio for objectively ascertained osteoarthrosis of the knee was 2.25 (95% confidence interval [1.41-3.61], I² = 71%). When only radiologically ascertained knee osteoarthrosis was considered, the odds ratio was 3.98 [1.34; 11.83], I² = 58%). The pooled risk estimator in studies in which knee joint macroinjury was excluded was 2.81 ([1.25; 6.32], I² = 71%).

CONCLUSION

A marked association was found between soccer playing and knee osteoarthritis in male professional soccer players. For female professional soccer players, the risk of knee osteoarthritis could not be assessed because of the lack of data. Knee injuries seem to play an important role in the development of knee osteoarthritis in professional soccer players.

Stationary cycling exercise for knee osteoarthritis: A systematic review and meta-analysis

OBJECTIVE

To evaluate effects of stationary cycling exercise on pain, function and stiffness in individuals with knee osteoarthritis.

DATA SOURCES

Systematic search conducted in seven databases (PubMed, Embase, Cochrane Library, Web of Science, EBSCO, PEDro, and CNKI) from inception to September 2020.

REVIEW METHODS

Included studies were randomized-controlled trials involving stationary cycling exercise conducted on individuals with knee osteoarthritis. End-trial weighted mean difference (WMD) and 95% confidence interval (CI) were analyzed, and random-effects models were used. Methodological quality and risk bias were assessed by using the Physiotherapy Evidence Database scale and Cochrane Collaboration tool, respectively.

RESULTS

Eleven studies with 724 participants were found, of which the final meta-analysis was performed with eight. Compared to a control (no exercise), stationary cycling exercise resulted in reduced pain (WMD 12.86, 95% CI 6.90-18.81) and improved sport performance (WMD 8.06, 95% CI 0.92-15.20); although most of the meta-analysis results were statistically significant, improvements in stiffness (WMD 11.47, 95% CI 4.69-18.25), function (WMD 8.28, 95% CI 2.44-14.11), symptoms (WMD 4.15, 95% CI -1.87 to 10.18), daily living (WMD 6.43, 95% CI 3.19 to 9.66) and quality of life (WMD 0.99, 95% CI -4.27 to 6.25) for individuals with knee osteoarthritis were not greater than the minimal clinically important difference values for each of these outcome measures.

CONCLUSIONS

Stationary cycling exercise relieves pain and improves sport function in individuals with knee osteoarthritis, but may not be as clinically effective for improving stiffness, daily activity, and quality of life.

Men and Women's Occupational Activities and the Risk of Developing Osteoarthritis of the Knee, Hip, or Hands: A Systematic Review and Recommendations for Future Research

Objective

To systematically review the evidence for an increased risk of osteoarthritis in the hip, knee, hand, wrist, finger, ankle, foot, shoulder, neck, and spine related to diverse occupational activities of men and women and to examine dose‐response information related to the frequency, intensity, and duration of work exposures and the risk of osteoarthritis (OA).

Methods

Established guidelines for systematic reviews in occupational health and safety studies were followed. MEDLINE, Embase, CINAHL, and Cochrane Library were searched from inception to December 2017. Studies were reviewed for relevance, quality was appraised, and data were extracted and synthesized.

Results

Sixty‐nine studies from 23 countries yielded strong and moderate evidence for lifting, cumulative physical loads, full‐body vibration, and kneeling/squatting/bending as increasing the risks of developing OA in men and women. Strong and moderate evidence existed for no increased risk of OA related to sitting, standing, and walking (hip and knee OA), lifting and carrying (knee OA), climbing ladders (knee OA), driving (knee OA), and highly repetitive tasks (hand OA). Variability in dose‐response data resulted in an inability to synthesize these data.

Conclusion

Evidence points to the potential for OA occupational recommendations and practice considerations to be developed for women and men. However, research attention is needed to overcome deficits in the measurement and recall of specific work activities so that recommendations and practice considerations can provide the specificity needed to be adopted in workplaces.

Development and evaluation of RAMP II - a practitioner's tool for assessing musculoskeletal disorder risk factors in industrial manual handling

RAMP II is an observation-based tool developed for assessing a wide range of musculoskeletal disorder risk factors related to industrial manual handling. RAMP II, which is part of the RAMP tool, is based on research studies and expert judgments. The assessment relies mainly on direct or video observations of the work being assessed, but additionally on measured push/pull forces and weights of handled objects, and on perceived workload and discomfort. Over 80 practitioners participated in the development of the tool. According to the evaluations, 73% of the assessment items evaluated had acceptable reliability, and the majority of the potential end-users reported that RAMP II is usable for assessing risks and as a decision base. It is concluded that this study provides support that RAMP II is usable for risk assessment of musculoskeletal disorder risk factors in industrial manual handling. Practitioner summary: RAMP II is an observation-based assessment tool for screening and assessing major musculoskeletal exposures in industrial manual handling jobs. Over 80 practitioners participated in the development of the tool. This study provides support that RAMP II is usable for risk assessment of musculoskeletal disorder risk factors in industrial manual handling. Abbreviations: CTS: carpal tunnel syndrome; HARM: the Hand Arm Risk Assessment method; IMP: intramuscular pressure; κ_w: linearly weighted kappa; LBD: lower back disorders; LBP: lower back pain; MAWL: maximum acceptable weight of lift; MHO: manual handling operations; MSD: musculoskeletal disorder; MNSD: neck-shoulder disorder; NSP: neck-shoulder pain; OCRA: the Occupational Repetitive Action methods; OHS: occupational health and safety; PABAK: prevalence and bias adjusted kappa; p₀: proportion of agreement; RAMP: Risk Assessment and Management tool for manual handling Proactively; ROM: range of motion; RPL: risk and priority level; RSI: the Revised Strain Index; RULA: the Rapid Upper Limb Assessment; SWEA: Swedish Work Environment Authority; UEMSDs: upper-extremity work-related musculoskeletal disorders; WMSD: work-related musculoskeletal disorder; WRMSD: work-related musculoskeletal disorder; workday_8h: eight hours workday.

Risk factors for development of lower limb osteoarthritis in physically demanding occupations: A narrative umbrella review

Objectives

Osteoarthritis (OA) is a common disorder which affects the joints. As relationships between occupational factors and lower limb OA have been widely studied in systematic reviews, the aim of this umbrella review was to synthesize their key findings in the risk factors for development of lower limb OA.

Methods

A systematic search was conducted using the databases PUBMED, Cumulative Index of Nursing and Allied Health Literature, and Elton B Stevens Company to identify reviews examining associations between lower limb OA and occupational tasks. These reviews were rated for their methodological quality before key data were extracted and synthesized.

Results

Sixteen reviews were found, seven pertained to the knee, four to the hip, two to a variety of joints, and three to both the hip and knee. One was deemed to be of high methodological quality, one of critically low methodological quality, and the others of moderate methodological quality. The reviews found moderate to good evidence for heavy occupational lifting to be associated with an increased risk of OA at the knee and the hip. Kneeling, squatting, and climbing, previous injuries to joints, being overweight and obese were also predictive of lower limb OA.

Conclusion

Occupations which involve heavy physical workloads increase the risk of developing lower limb OA. Heavy lifting, squatting, knee bending, kneeling, and climbing may all increase the risk of developing OA in both the knees and hips. Efforts to reduce exposure to these tasks, reducing joint injuries, optimizing bodyweight may reduce the risks of lower limb OA for occupations which are physically demanding.

Inhibiting the PI3K/AKT/NF-κB signal pathway with nobiletin for attenuating the development of osteoarthritis: in vitro and in vivo studies

Osteoarthritis (OA), an age-related degenerative disease, is characterized by progressive degradation of the articular cartilage. There is increasing evidence that nobiletin (NOB) exerts special biological functions in a variety of diseases. However, whether it protects against OA remains unknown. In this study, we investigated the anti-inflammatory and chondroprotective effects of NOB on IL-1β-induced human OA chondrocytes and in the surgical DMM mice OA models. In vitro, NOB treatment completely suppressed the overproduction of pro-inflammatory mediators, including PGE2, NO, COX-2, iNOS, TNF-α and IL-6 in IL-1β-induced human OA chondrocytes. Moreover, NOB exerted a potent inhibitory effect on the expression of MMP-13 and ADAMTS-5 as well as the degradation of aggrecan and collagen-II, which leads to the degradation of the extracellular matrix. Furthermore, NOB dramatically suppressed the IL-1β-stimulated phosphorylation of PI3K/Akt and activation of NF-κB in human OA chondrocytes. In addition, treatment with NOB not only prevented the destruction of cartilage and the thickening of subchondral bone but also relieved synovitis in mice OA models. In conclusion, our study suggests that NOB holds novel therapeutic potential for the treatment of OA.

Reconsidering osteoarthritis as a skeletal indicator of age at death

OBJECTIVES

Osteoarthritis (OA) generally increases with age, but it is a complex, multifactorial disease. This study investigated whether obesity, physical activity, and antemortem trauma preclude the use of OA for skeletal age estimation.

MATERIALS AND METHODS

The temporomandibular joint (TMJ) and all appendicular joints were scored for skeletal indicators of OA in 408 modern European-Americans (Bass Collection, TN). Binomial generalized linear models (GLMs) assessed the contributions of self-reported demographic data to OA, including: age; body mass index (BMI); and metabolic values for physical activities. Repeated resampling tested whether observed mean OA scores for joints with trauma consistently exceeded mean scores for unaffected joints. Single-variable GLM probit models were generated for OA presence/absence data in relevant joints.

RESULTS

Age was the only statistically significant predictor of OA in most multivariable GLMs. Occupation and age were both significant predictors of male hand OA; BMI was the only significant predictor of female ankle OA. Trauma significantly affected OA in most joints. Age cut-offs calculated from the single-variable probit models (representing ages of transition to "OA present") ranged from 29.7 to 77.3 years (90%) and 32.7 to 96.6 years (95%), but were problematic for the male TMJ.

DISCUSSION

Ankle OA should not be used to age females; TMJ OA should not be used to age males. For other joints, using OA to inform age estimates appears valid (in absence of antemortem trauma). While skeletal evidence of OA is not a primary age indicator, its presence can refine age ranges and provide essential age data in fragmentary cases.

Risk factors of knee osteoarthritis: A case-control study

Background and Objective

Knee osteoarthritis is one of the most common rheumatologic problems. To investigate risk factors related to the knee osteoarthritis a case-control study was performed using cases diagnosed in the Community Oriented Program for Control of Rheumatic Diseases (COPCORD) study, stage I.

Methods

Using data from the 2012 COPCORD study, stage-I that was conducted in Sanandaj, northwestern of Iran, we runned a case-control study in 2014-2015. Cases were 700 knee osteoarthritis using American College of Rheumatology (ACR) criteria, frequency matched with 700 healthy controls that were randomly selected from the general population.

Results

In multivariate analysis, statistical significant relation was observed between knee OA and some studied factors such as body mass index (P <0.001), lodging (living in highland vs. plain) (P <0.001), type of used toilet (regular vs. toilet) (P <0.001), history of using high-heeled shoes (>3 cm) (P = 0.005), history of knee Injury (P = 0.04), history of lower limb fracture (P = 0.02), Number of pregnancies (P <0.001) and history of pain and swelling (lasting for one months) (P = 0.04).

Conclusions

Living in highland area, using regular toilet, having knee injury and lower limb fracture in the past were most significant associated factors with occurrence of knee osteoarthritis.

Photo-crosslinked HAMA hydrogel with cordycepin encapsulated chitosan microspheres for osteoarthritis treatment

Autophagy is a protective mechanism in normal cartilage. The present study aimed to investigate the synergistic therapeutic effect of promotion of chondrocyte autophagy via exposure to cordycepin encapsulated by chitosan microspheres (CM-cordycepin) and photo-crosslinked hyaluronic acid methacrylate (HAMA) hydrogel, with the goal of evaluating CM-cordycepin as a treatment for patients with osteoarthritis. First, we developed and evaluated the characteristics of HAMA hydrogels and chitosan microspheres. Next, we measured the effect of cordycepin on cartilage matrix degradation induced by IL1-β in chondrocytes and an ex vivo model. Cordycepin protects cartilage from degradation partly by activation of autophagy. Moreover, we surgically induced osteoarthritis in mice, which were injected intra-articularly with CM-cordycepin and HAMA. The combination of CM-cordycepin and HAMA hydrogel retarded the progression of surgically induced OA. Cordycepin ameliorated cartilage matrix degradation at least partially by inducing autophagy in vivo. Our results demonstrate that the combination of cordycepin encapsulated by CMs and photo-crosslinked HAMA hydrogel could be a promising strategy for treating patients with osteoarthritis.

The amelioration of cartilage degeneration by photo-crosslinked GelHA hydrogel and crizotinib encapsulated chitosan microspheres

The present study aimed to investigate the synergistic therapeutic effect of decreasing cartilage angiogenesis via exposure to crizotinib encapsulated by chitosan microspheres and photo-crosslinked hydrogel, with the goal of evaluating crizotinib as a treatment for osteoarthritis. First, we developed and evaluated the characteristics of hydrogels and chitosan microspheres. Next, we measured the effect of crizotinib on the cartilage degeneration induced by interleukin-1β in chondrocytes. Crizotinib ameliorated the pathological changes induced by interleukin-1β via its anti-angiogenesis function. In addition, we surgically induced osteoarthritis in mice, which were then injected intra-articularly with crizotinib-loaded biomaterials. Cartilage matrix degradation, expression of vascular endothelial growth factor and extracellular signal-regulated kinases 1/2 were evaluated after surgery. Treatment with the combination of crizotinib-loaded biomaterials retarded the progression of surgically induced osteoarthritis. Crizotinib ameliorated cartilage matrix degradation by promoting anti-angiogenesis and impeding extracellular signal-regulated kinases 1/2 signaling pathway. Our results demonstrate that the combination of photo-crosslinked hydrogel and crizotinib-loaded chitosan microspheres might represent a promising strategy for osteoarthritis treatment.

The Association of Recreational and Competitive Running With Hip and Knee Osteoarthritis: A Systematic Review and Meta-analysis

Study Design Systematic review and meta-analysis. Background Running is a healthy and popular activity worldwide, but data regarding its association with osteoarthritis (OA) are conflicting. Objectives To evaluate the association of hip and knee OA with running and to explore the influence of running intensity on this association. Methods PubMed, Embase, and Cochrane Library databases were used to identify studies investigating the occurrence of OA of the hip and/or knee among runners. A meta-analysis of studies comparing this occurrence between runners and controls (sedentary, nonrunning individuals) was conducted. Runners were regarded as "competitive" if they were reported as professional/elite athletes or participated in international competitions. Recreational runners were individuals running in a nonprofessional (amateur) context. The prevalence rate and odds ratio (with 95% confidence interval [CI]) for OA between runners (at competitive and recreational levels) and controls were calculated. Subgroup analyses were conducted for OA location (hip or knee), sex, and years of exposure to running (less or more than 15 years). Results Twenty-five studies (n = 125810 individuals) were included and 17 (n = 114829 individuals) were meta-analyzed. The overall prevalence of hip and knee OA was 13.3% (95% CI: 11.6%, 15.2%) in competitive runners, 3.5% (95% CI: 3.4%, 3.6%) in recreational runners, and 10.2% (95% CI: 9.9%, 10.6%) in controls. The odds ratio for hip and/or knee OA in competitive runners was higher than that in recreational runners (1.34; 95% CI: 0.97, 1.86 and 0.86; 95% CI: 0.69, 1.07, respectively; controls as reference group; for difference, P<.001). Exposure to running of less than 15 years was associated with a lower association with hip and/or knee OA compared with controls (OR = 0.6; 95% CI: 0.49, 0.73). Conclusion Recreational runners had a lower occurrence of OA compared with competitive runners and controls. These results indicated that a more sedentary lifestyle or long exposure to high-volume and/or high-intensity running are both associated with hip and/or knee OA. However, it was not possible to determine whether these associations were causative or confounded by other risk factors, such as previous injury. Level of Evidence Etiology/harm, level 2a. J Orthop Sports Phys Ther 2017;47(6):373-390. doi:10.2519/jospt.2017.7137.

Sanguinarine protects against osteoarthritis by suppressing the expression of catabolic proteases

Inflammatory cytokines play critical roles in the pathogenesis of osteoarthritis. Recent studies have demonstrated that natural active substances can serve as alternative therapeutic agents for the prevention and treatment of osteoarthritis. Sanguinarine, an alkaloid isolated from the roots of Sanguinaria canadensis, is known to have anti-inflammatory properties. The aim of the present study was to investigate the therapeutic effect of Sanguinarine against osteoarthritis. Sanguinarine inhibited interleukin-1β-induced expression of matrix metalloproteinase 1, 3, and 13, and A disintegrin and metalloproteinase with thrombospondin motifs-5 in chondrocytes, which involved the nuclear factor-κB and c-Jun N-terminal kinase signalling pathways. Furthermore, the study of interleukin-1β-induced cartilage matrix degradation in an anterior cruciate ligament transection-induced osteoarthritis model revealed that Sanguinarine ameliorated osteoarthritis by inhibiting the expression of matrix metalloproteinase 1, 3, and 13, and A disintegrin and metalloproteinase with thrombospondin motifs-5. In conclusion, we demonstrated for the first time that Sanguinarine suppressed the expression of matrix metalloproteinase 1, 3, and 13, and A disintegrin and metalloproteinase with thrombospondin motifs-5 in vitro, ex vivo, and in vivo, indicating its potential usefulness in treating osteoarthritis.

Self-regulation in older Thai women with self-reported knee osteoarthritis: A path analysis

This study aimed at testing factors influencing coping behavior and health status among older women with knee osteoarthritis. A total of 274 participants completed questionnaires. Model testing revealed that self-efficacy was the most powerful predictor of coping behavior. Illness representation had a significant direct and indirect effect on health status and was a better predictor of health status than were the other variables. Understanding the complex relationships among study variables should help to tailor future interventions to better address the symptoms of osteoarthritis and to promote optimal health in older Thai women who report knee osteoarthritis.

Epidemiology of rheumatic diseases in Iran from analysis of four COPCORD studies

AIM

To calculate the epidemiology of Rheumatic Diseases in Iran.

MATERIALS AND METHODS

The data of Tehran, Zahedan, Sanandaj (urban) and Tuyserkan (rural) stage Community Oriented Program for the Control of Rheumatic Diseases (COPCORD) studies were gathered. The data were adjusted to the population number of the studied areas to represent Iran.

RESULTS

The population of Iran is 75 149 669 (71.5% urban areas, males 50.4%) and of the mentioned area were respectively 10 000 000, 580 071, 311 444 and 109 262. The interviewed subjects were 10 291, 1565, 2100 and 5830. Male/female ratio was 0.9/1, 0.8/1, 08/1 and 0.8/1. Musculoskeletal complaints during the past 7 days (people aged ≥ 15 years) were detected in 44.7% of subjects. They were: shoulder 15.6%, wrist 10.4%, hands and fingers 10.2%, hip 8.3%, knee 27.4%, ankle 12.3%, toes 6.2%, cervical spine 14.2% and dorsolumbar spine 23.7%. Osteoarthritis (OA) was detected in 16.9%: knee 15.5%, hands 2.9% and hip 0.32%. Low back pain was found in 15.7%, sciatica in 0.94%, and soft tissue rheumatism in 4.6% (shoulder tenosynovitis 2.5%, frozen shoulder 0.56%, tennis elbow 1.2%, golf elbow 0.48%, de Quervain tenosynovitis 0.24%, trigger finger 0.2%, carpal tunnel syndrome 1.3%). Rheumatoid arthritis was detected in 0.37%, seronegative spondyloarthropathy in 0.24%, ankylosing spondylitis in 0.12%, systemic lupus erythematosus in 0.06%, Behcet's disease in 0.08%, fibromyalgia in 0.79% and gout in 0.13%.

CONCLUSION

Compared to other COPCORD reports (17 countries), Iran gets the following rank: musculoskeletal complaints second, low back pain fourth, osteoarthritis second, knee osteoarthritis third, soft tissue rheumatism sixth, rheumatoid arthritis tenth, seronegative spondyloarthropathies fifth, gout eleventh and fibromyalgia fifth.

Mesenchymal stem cell therapy for knee osteoarthritis: 5 years follow-up of three patients

AIM

Osteoarthritis is a degenerative joint disease characterized by the destruction of joint cartilage. Mesenchymal stem cells (MSCs) are found in low numbers in normal cartilage, mainly in the superficial layer, acting as repairing agents. In OA, MSCs are seen in larger numbers, but act chaotic and are unable to repair the cartilage. The synovial membrane becomes inflamed and interacts with the cartilage. Transplanted MSC have the ability to normalize them, redirecting them to their normal function. In a preliminary study, we showed that MSC could improve knee OA in four patients at 6 months. This report shows their long-term follow-up at 5 years.

METHODS

One patient was lost to follow-up at 2 years and three were followed for 5 years. They were aged 55, 57, 65 and 54 years, and had moderate to severe knee osteoarthritis. The worse knee of each patient was injected with 8-9 × 10(6) MSC.

RESULTS

As previously reported, all parameters improved in transplant knees at 6 months (walking time, stair climbing, gelling pain, patella crepitus, flection contracture and the visual analogue score on pain). Then, they started gradually to deteriorate, but at 5 years they were still better than at baseline. PGA (Patient Global Assessment) improved from baseline to 5 years. The better knee at baseline (no MSC), continued its progression toward aggravation and at 5 years became the worse knee.

CONCLUSION

Transplant knees were all in a rather advanced stage of OA. Earlier transplantation may give better results in long-term follow-up. This is what future studies have to demonstrate.

Effects of toe-in angles on knee biomechanics in cycling of patients with medial knee osteoarthritis

BACKGROUND

Cycling is commonly prescribed for knee osteoarthritis, but previous literature on biomechanics during cycling and the effects of acute intervention on osteoarthritis patients does not exist. Due to their altered knee kinematics, osteoarthritis patients may be at greater risk of osteoarthritis progression or other knee injuries during cycling. This study investigated the effects of reduced foot progression (toe-in) angles on knee joint biomechanics in subjects with medial compartment knee osteoarthritis.

METHODS

Thirteen osteoarthritis and 11 healthy subjects participated in this study. A motion analysis system and custom instrumented pedal was used to collect 5 pedal cycles of kinematic and kinetic data in 1 neutral and 2 toe-in conditions (5° and 10°) at 60 RPM and 80W.

FINDINGS

For peak knee adduction angle, there was a 61% (2.7°) and a 73% (3.2°) decrease in the 5° and 10° toe-in conditions compared to neutral in the osteoarthritis group and a 77% (1.7°) and 109% (2.4°) decrease in the healthy group for the 5° and 10° conditions, respectively. This finding was not accompanied by a decrease in pain or peak knee abduction moment. A simple linear regression showed a positive correlation between Kelgren-Lawrence score and both peak knee adduction angle and abduction moment.

INTERPRETATION

For individuals who cycle with increased knee adduction angles, decreasing the foot progression angle may be beneficial for reducing the risk of overuse knee injuries during cycling by resulting in a frontal plane knee alignment closer to a neutral position.

Current perspectives in mesenchymal stem cell therapies for osteoarthritis

Osteoarthritis (OA) is a degenerative joint disease most commonly occurring in the ageing population. It is a slow progressive condition resulting in the destruction of hyaline cartilage followed by pain and reduced activity. Conventional treatments have little effects on the progression of the condition often leaving surgery as the last option. In the last 10 years tissue engineering utilising mesenchymal stem cells has been emerging as an alternative method for treating OA. Mesenchymal stem cells (MSCs) are multipotent progenitor cells found in various tissues, most commonly bone marrow and adipose tissue. MSCs are capable of differentiating into osteocytes, adipocytes, and chondrocytes. Autologous MSCs can be easily harvested and applied in treatment, but allogenic cells can also be employed. The early uses of MSCs focused on the implantations of cell rich matrixes during open surgeries, resulting in the formation of hyaline-like durable cartilage. More recently, the focus has completely shifted towards direct intra-articular injections where a great number of cells are suspended and injected into affected joints. In this review the history and early uses of MSCs in cartilage regeneration are reviewed and different approaches in current trends are explained and evaluated.

Exercise and osteoarthritis: cause and effects

Osteoarthritis (OA) is a common chronic joint condition predominantly affecting the knee, hip, and hand joints. Exercise plays a role in the development and treatment of OA but most of the literature in this area relates to knee OA. While studies indicate that exercise and physical activity have a generally positive effect on healthy cartilage metrics, depending upon the type of the activity and its intensity, the risk of OA development does appear to be moderately increased with sporting participation. In particular, joint injury associated with sports participation may be largely responsible for this increased risk of OA with sport. Various repetitive occupational tasks are also linked to greater likelihood of OA development. There are a number of physical impairments associated with OA including pain, muscle weakness and altered muscle function, reduced proprioception and postural control, joint instability, restricted range of motion, and lower aerobic fitness. These can result directly from the OA pathological process and/or indirectly as a result of factors such as pain, effusion, and reduced activity levels. These impairments and their underlying physiology are often targeted by exercise interventions and evidence generally shows that many of these can be modified by specific exercise. There is currently little clinical trial evidence to show that exercise can alter mechanical load and structural disease progression in those with established OA, although a number of impairments, that are amenable to change with exercise, appears to be associated with increased mechanical load and/or disease progression in longitudinal studies.

WHO-ILAR COPCORD study (stage 1, urban study) in Sanandaj, Iran

This study aims to conduct an urban Community Oriented Program for Control Of Rheumatic Diseases (COPCORD) study in Sanandaj (Kurdistan, Iran). Sanandaj with a population of 311,446 (2006 census), Caucasian of Kurdish subgroup, was selected as the field. Sanandaj was divided into 100 clusters and subjects were randomly selected from them (50 subjects from each cluster). The COPCORD study started on July 2011 and ended on June 2012. Of the households, 1,631 was visited and 5,830 persons were interviewed. The male to female ratio was 0.8-1 (44.5% males, 55.5% females). Musculoskeletal complaints during the past 7 days were detected in 42.8% of the interviewed subjects (36.3% males, 48.1% females). The distribution was 16.7% shoulder, 10% wrist, 9.7% hands and fingers, 7.7% hip, 26.3% knee, 9.9% ankle, 6.4% toes, 9.5% cervical spine, and 21.5% dorsal and lumbar spine. Degenerative joint diseases were detected in 19.4% of the subjects: 1.8% neck, 18.9% knee, 3.9% hands, and 0.51% hip. Low back pain was detected in 16.5%, sciatica in 1.2%, cervical nerve root pain in 0.24%, and soft tissue rheumatism in 5.5%. Inflammatory disorders were 0.51% rheumatoid arthritis, 0.22% seronegative spondyloarthropathy, 0.10% ankylosing spondylitis, 0.05% systemic lupus erythematosus, and 0.10% Behcet's disease . Fibromyalgia was detected in 0.62% and gout in 0.12% of the studied population. Disability was reported by 28.3%. It was present at the study time in 21.4%. Comparing the four COPCORD studies of Iran, the figures (numbers) obtained by COPCORD Sanandaj are much the same as the COPCORD study in Tehran. Joint complaints were seen less frequently than in the COPCORD urban study of Zahedan and rural study of Tuyserkan. Osteoarthritis was higher than in Tehran, but the same as the two others. Soft tissue rheumatism was rather the same. Rheumatoid arthritis was higher than Tehran and Tuyserkan, but lower than Zahedan.

The clinical pattern of knee osteoarthritis in Jordan: a hospital based study

BACKGROUND

Different clinical profiles of knee osteoarthritis (KOA) have been reported in the literature. The aim of this investigation was to describe the clinical patterns of KOA in an ethnically distinct and homogenous population that has not been widely reported. Patients with KOA were seen in outpatient rehabilitation and orthopedic clinic of Jordan University Hospital (JUH), to determine any possible association between age, BMI, radiographic severity, and pain severity.

METHODS

Patients diagnosed with KOA attending an outpatient rehabilitation clinic at JUH were studied to describe their clinical characteristics. They were included based on criteria developed by the American College of Rheumatology. Detailed histories, clinical examinations and X-rays, and anthropometric data were obtained. Data analysis focused on descriptive statistics and correlations among demographic and clinical characteristics.

RESULTS

The study included 214 patients with a mean age of 55.3 years (range = 30-84 years). The mean BMI was 29.5± 5.6. We found a significant moderate positive correlation between age and radiographic severity of KOA (0.435; p <. 001) and pain severity (0.383; p. <. 001). There was also a significant weak positive correlation between BMI, radiographic severity of KOA (0.242, p <. 05), and pain severity (0.266, p. <. 01).

CONCLUSIONS

We concluded that in this hospital-based cohort study in Jordan, the clinical pattern of KOA is comparable to Western cultures. However, the combination of BMI and mechanical loading during everyday activities that include different religious and cultural habits and may help explain the high level of radiographic severity in our sample.

Loading of the knee joint during ergometer cycling: telemetric in vivo data

STUDY DESIGN

Within-subject, repeated-measures design.

OBJECTIVES

To measure tibiofemoral contact forces during cycling in vivo and to quantify the influences of power, pedaling cadence, and seat height on tibiofemoral contact forces.

BACKGROUND

Cycling is usually classified as a low-demand activity for the knee joint and is therefore recommended for persons with osteoarthritis and rehabilitation programs following knee surgery. However, there are limited data regarding actual joint loading.

METHODS

Instrumented knee implants with telemetric data transmission were used to measure the tibiofemoral contact forces. Data were obtained in 9 subjects, during ergometer cycling and walking, 15 ± 7 months after total knee arthroplasty. Tibiofemoral forces during cycling at power levels between 25 and 120 W, cadences of 40 and 60 rpm, and 2 seat heights were investigated.

RESULTS

Within the examined power range, tibiofemoral forces during cycling were smaller than those during walking. At the moderate condition of 60 W and 40 rpm, peak resultant forces of 119% of body weight were measured during the pedal downstroke. Shear forces ranged from 5% to 7% of body weight. Forces increased linearly with cycling power. Higher cadences led to smaller forces. A lower seat height did not increase the resultant force but caused higher posterior shear forces.

CONCLUSION

Due to the relatively small tibiofemoral forces, cycling with moderate power levels is suited for individuals with osteoarthritis and rehabilitation programs following knee surgery, such as cartilage repair or total knee replacement. The lowest forces can be expected while cycling at a low power level, a high cadence, and a high seat height.

Occupational activities and osteoarthritis of the knee

BACKGROUND

The prevalence of knee osteoarthritis (OA) is rising and the search for interventions to mitigate risk is intensifying. This review considers the contribution of occupational activities to disease occurrence and the lessons for prevention.

SOURCES

Systematic search in Embase and Medline covering the period 1996 to November 2011.

AREAS OF AGREEMENT

Reasonably good evidence exists that physical work activities (especially kneeling, squatting, lifting and climbing) can cause and/or aggravate knee OA. These exposures should be reduced where possible. Obese workers with such exposures are at additional risk of knee OA and should therefore particularly be encouraged to lose weight. AREAS OF UNCERTAINTY/RESEARCH NEED: Workplace interventions and policies to prevent knee OA have seldom been evaluated. Moreover, their implementation can be problematic. However, the need for research to optimize the design of work in relation to knee OA is pressing, given population trends towards extended working life.

The effect of adding whole-body vibration to squat training on the functional performance and self-report of disease status in elderly patients with knee osteoarthritis: a randomized, controlled clinical study

OBJECTIVES

The study objectives were to evaluate the effects of adding whole-body vibration to squat training on functional performance and self-report of disease in elderly individuals with knee osteoarthritis (OA).

DESIGN

This was a prospective, randomized trial in which selected variables were evaluated at three periods: 3 weeks prior to the training, immediately prior, and after the end of the training.

SUBJECTS

Twenty-three (23) elderly subjects were evaluated using four functional performance tests: Berg Balance Scale (BBS), Timed Get Up and Go Test (TGUG), Chair Stand Test (CST), and 6-Minute Walk Test (6MWT), and a self-report of the status of disease (WOMAC).

INTERVENTIONS

The intervention lasted for 12 weeks, 3 times per week. The participants were randomized into two groups: (1) squat training with whole-body vibration, and (2) squat training without vibration.

RESULTS

Although there was no statistical difference in functional performance and self-report of disease status between the groups, performance in all the functional tests and in all the domains of WOMAC improved in the vibration group compared to their initial status. In the exercise group, performance improved only two tests (BBS and 6MWT), and there was a reduction in self-reported pain (WOMAC) compared to their initial status.

CONCLUSIONS

Although the addition of whole-body vibration to squat training failed to result in a significant improvement in functional performance and self-reported status of knee osteoarthritis in the elderly, the intragroup results suggest that whole-body vibration may represent a feasible and effective way of improving the functionality and self-perception of disease status in older adults with knee OA.

Physical activity is associated with magnetic resonance imaging-based knee cartilage T2 measurements in asymptomatic subjects with and those without osteoarthritis risk factors

OBJECTIVE

To evaluate the association of exercise and knee-bending activities with magnetic resonance imaging (MRI)-based knee cartilage T2 relaxation times and morphologic abnormalities in asymptomatic subjects from the Osteoarthritis Initiative, with or without osteoarthritis (OA) risk factors.

METHODS

We studied 128 subjects with knee OA risk factors and 33 normal control subjects ages 45-55 years, with a body mass index of 18-27 kg/m(2) and no knee pain. Subjects were categorized according to exercise level, using the leisure activity component of the Physical Activity Scale for the Elderly, and by self-reported frequent knee-bending activities. Two radiologists graded the cartilage of the right knee on MR images, using the Whole-Organ MRI Score (WORMS). Cartilage was segmented, and compartment-specific T2 values were calculated. Differences between the exercise groups and knee-bending groups were determined using multiple linear and logistic regression models.

RESULTS

Among subjects with risk factors for knee OA, light exercisers had lower T2 values compared with sedentary and moderate/strenuous exercisers. When the sexes were analyzed separately, female moderate/strenuous exercisers had higher T2 values compared with sedentary individuals and light exercisers. Subjects without risk factors displayed no significant differences in T2 values according to exercise level. However, frequent knee-bending activities were associated with higher T2 values in both subjects with OA risk factors and those without OA risk factors and with more severe cartilage lesions in the group with risk factors.

CONCLUSION

In subjects at risk of knee OA, light exercise was associated with low T2 values, whereas moderate/strenuous exercise in women was associated with high T2 values. Higher T2 values and WORMS grades were also observed in frequent knee-benders, suggesting greater cartilage degeneration in these individuals.

Osteoarthritis of the knees in the COPCORD world

This paper examines and summarizes data on knee osteoarthritis (AO) in Community Oriented Program For Control Of Rheumatic Disorders (COPCORD) publications. A literature search was made through PubMed, Google, Proceedings of Asia-Pacific League of Associations for Rheumatology (APLAR) congresses, and Abstracts from APLAR congresses. Data were compiled to examine the prevalence of knee OA and knee pain, sex ratio, urban/rural differences and other risk factors. Data on knee pain and OA were available in a total of 36 COPCORD publications. The pooled prevalence of knee OA was 7.9% in adults above the age of 15 years. It was more common in women. Overweight, squatting and cycling appeared to be modifiable risk factors for knee OA. OA of the knee is the commonest rheumatic disease in studied communities. Further research is needed for identification of its modifiable risk factors and development of strategies for reduction of the community burden of this malady.

Occupational risk factors for osteoarthritis of the knee: a meta-analysis

INTRODUCTION

Systematic reviews agree that knee osteoarthritis (OA) is related to occupational activities, but have not quantified the overall risks.

METHODS

Systematic review of observational studies of knee OA and occupation. Job titles, elite sport, heavy work, kneeling, and other activities were included. Relative risk estimate and 95% confidence interval (CI) compared to sedentary work were retrieved or calculated for meta-analysis. Publication bias was examined with Egger tests and heterogeneity was determined with I(2) values and Q tests. Subgroup analysis was performed to examine causes of heterogeneity. A random effects model was performed to combine the data.

RESULTS

Studies of knee OA (n=51), persistent knee pain (n=12) and knee OA progression (n=3) were retrieved. Occupational risks for knee OA were examined in a total of 526,343 subjects in 8 cohort/prospective/longitudinal studies, 25 cross-sectional studies and 18 case control studies. The overall odds ratio (OR) was 1.61 (95% CI 1.45-1.78) with significant heterogeneity (I(2)=83.6%). Study designs showed a positive association between knee OA and occupational activities; cohort (OR 1.38, 95% CI 1.10-1.74), cross-sectional (OR 1.57, 95% CI 1.37-1.81) and case control (OR 1.80, 95% CI 1.48-2.19). Overall there was evidence of publication bias (P<0.0001) which was apparent in the cross-sectional and case control studies (P<0.0001 and P=0.0247 respectively).

CONCLUSIONS

Some occupational activities increase the risk of knee OA, although the influences of publication bias and heterogeneity are important limitations of this study. Prospective studies would greatly improve the evidence base.

Mesenchymal stem cell therapy for knee osteoarthritis. Preliminary report of four patients

BACKGROUND

Osteoarthritis (OA) is a cartilage degenerative process, involving the immune system, producing local inflammatory reactions, with production of pro-inflammatory cytokines and metalloproteinases. No treatment is still available to improve or reverse the process. Stem cell therapy opened new horizons for treatment of many incurable diseases. Mesenchymal stem cells (MSCs) due to their multi-lineage potential, immunosuppressive activities, limited immunogenicity and relative ease of growth in culture, have attracted attentions for clinical use.

AIM

The aim of this study was to examine whether MSC transplantation could reverse the OA process in the knee joint. The project was approved by the Tehran University of Medical Sciences Research Committee and Ethical Committee.

PATIENTS AND METHODS

Four patients with knee osteoarthritis were selected for the study. They were aged 55, 57, 65 and 54 years, and had moderate to severe knee OA. After their signed written consent, 30 mL of bone marrow were taken and cultured for MSC growth. After having enough MSCs in culture (4-5 weeks) and taking in consideration all safety measures, cells were injected in one knee of each patient.

RESULTS

The walking time for the pain to appear improved for three patients and remained unchanged for one. The number of stairs they could climb and the pain on visual analog scale improved for all of them. On physical examination, the improvement was mainly for crepitus. It was minor for the improvement of the range of motion.

CONCLUSION

Results were encouraging, but not excellent. Improvement of the technique may improve the results.

Effect of neuromuscular electrical muscle stimulation on energy expenditure in healthy adults

Weight loss/weight control is a major concern in prevention of cardiovascular disease and the realm of health promotion. The primary aim of this study was to investigate the effect of neuromuscular electrical stimulation (NMES) at different intensities on energy expenditure (oxygen and calories) in healthy adults. The secondary aim was to develop a generalized linear regression (GEE) model to predict the increase of energy expenditure facilitated by NMES and identify factors (NMES stimulation intensity level, age, body mass index, weight, body fat percentage, waist/hip ratio, and gender) associated with this NMES-induced increase of energy expenditure. Forty sedentary healthy adults (18 males and 22 females) participated. NMES was given at the following stimulation intensities for 10 minutes each: sensory level (E1), motor threshold (E2), and maximal intensity comfortably tolerated (E3). Cardiopulmonary gas exchange was evaluated during rest, NMES, and recovery stage. The results revealed that NMES at E2 and E3 significantly increased energy expenditure and the energy expenditure at recovery stage was still significantly higher than baseline. The GEE model demonstrated that a linear dose-response relationship existed between the stimulation intensity and the increase of energy expenditure. No subject’s demographic or anthropometric characteristics tested were significantly associated with the increase of energy expenditure. This study suggested NMES may be used to serve as an additional intervention for weight loss programs. Future studies to develop electrical stimulators or stimulation electrodes to maximize the comfort of NMES are recommended.

Development of a questionnaire for identification of the risk factors for osteoarthritis of the knees in developing countries. A pilot study in Iran and Bangladesh. An ILAR-COPCORD phase III study

BACKGROUND

Knee osteoarthritis (OA) is one of the most prevalent rheumatic disorders in the Asia-Pacific region. Identification of modifiable risk factors is important for development of strategies for primary and secondary prevention of knee OA.

OBJECTIVE

Developing a core questionnaire for identification of risk factors of knee OA at the community level.

METHODS

Steps performed: (1) item generation from literature, existing knee OA questionnaires and patient focus group discussions; (2) development of a preliminary APLAR-COPCORD English questionnaire; (3) translation into target language, back translation and development of a pre-final target language version; (4) adaptation of the pre-final target language version through tests of comprehensibility, content validity, test-retest reliability; and (5) finalization of the English questionnaire. Investigators in Bangladesh, Iran, China, Philippines and Indonesia participated in steps 1 and 2. Subsequent steps were carried out by Bangladeshi and Iranian investigators.

RESULTS

Fifty-three items were generated. Fourteen were obtainable from physical examination and placed in an examination sheet. Two radiological items were not included. A preliminary English questionnaire comprising the remaining 37 items was constructed and translated into Bengali and Persian. The preliminary Bengali and Persian versions were adapted as a result of tests of comprehensibility, content validity and test-retest reliability. The English questionnaire was adapted through repeated exchange of ideas and experiences among participating investigators. A 35-item English core questionnaire was finally developed.

CONCLUSION

The questionnaires may be used to identify risk factors of knee OA in Asia-Pacific communities after validation and further adaptation. From these data strategies for primary and secondary prevention of knee OA can be developed.