Racialized Inequities in Knee Arthroplasty Receipt After Osteoarthritis Diagnosis in the US Military Health System

OBJECTIVE

The goal was to evaluate institutional inequities in the US Military Health System in knee arthroplasty receipt within three years of knee osteoarthritis diagnosis when accounting for other treatments received (eg, physical therapy, medications).

METHODS

In this retrospective observational cohort study, medical record data of patients (n = 29,734) who received a primary osteoarthritis diagnosis in the US Military Health System between January 2016 and January 2020 were analyzed. Data included receipt of physical therapy one year before diagnosis and up to three years after diagnosis, prediagnosis opioid and nonopioid prescription receipt, health-related factors associated with levels of racism, and the primary outcome, knee arthroplasty receipt within three years after diagnosis.

RESULTS

In a generalized additive model with time-varying covariates, Asian and Pacific Islander (incidence rate ratio [IRR] 0.58, 95% confidence interval [CI] 0.45-0.74), Black (IRR 0.52, 95%CI 0.46-0.59), and Latine (IRR 0.66, 95%CI 0.52-0.85) patients experienced racialized inequities in knee arthroplasty receipt, relative to white patients (all P < 0.001).

CONCLUSIONS

In the present sample, Asian and Pacific Islander, Black, and Latine patients were significantly less likely to receive a knee arthroplasty, relative to white patients. Taken together, system-level resources are needed to identify and address mechanisms underlying institutional inequities in knee arthroplasty receipt, such as factors related to systemic and structural, institutional, and personally mediated racism.

Evaluation of relationship between DNA methyltransferase 3 β gene and the risk of hip osteoarthritis: A case-control study based on a Han Chinese population

AIM

Osteoarthritis (OA) is a chronic degenerative joint disease. Early studies have indicated that genetic and environmental factors contribute to the risk of OA. However, the etiology of OA remains unknown. Our study aimed to evaluate the association of DNMT3B gene with the risk of hip OA in Han Chinese individuals.

METHODS

A total of 2070 subjects were recruited into the study, including 658 patients with hip OA and 1412 healthy controls. Twelve tag single nucleotide polymorphisms (SNPs) were selected and genotyped in our samples. Genetic associations between DNMT3B gene and the risk of hip OA were examined at both the single marker and haplotype levels. Cis-expression quantitative trait loci signals that achieve genome-wide significance of targeted SNPs from multiple types of human tissues were extracted from the GTEx database.

RESULTS

Significant signals were identified for SNP rs2424905 in 4 genetic models. The T allele was significantly associated with an increased risk of hip OA (odds ratio = 1.53; 95% CI = 1.28-1.83). The T allele was also significantly associated with higher Kellgren-Lawrence grade in the patients with hip OA (χ2  = 32.70, P = 1.37 × 10-6 ). Moreover, SNP rs2424905 was significantly associated with the gene expression level of multiple genes, including DNMT3B, C20orf203, COMMD7, EFCAB8, MAPRE1, and RP5-1085F17.3, from several types of human tissues.

CONCLUSION

Our results indicated that rs2424905 of DNMT3B gene contributed to the risk of hip OA and its clinical severity in a Han Chinese population. These findings suggested that rs2424905 of DNMT3B could be a promising genetic marker to assess susceptibility to hip OA in Han Chinese populations.

The Unequal Effect of Income on Risk of Overweight/Obesity of Whites and Blacks with Knee Osteoarthritis: the Osteoarthritis Initiative

BACKGROUND

Although the protective effect of socioeconomic status (SES) against risk of overweight/obesity is well established, such effects may not be equal across diverse racial and ethnic groups, as suggested by the marginalization-related diminished returns (MDR) theory.

AIMS

Built on the MDR theory, this study explored racial variation in the protective effect of income against overweight/obesity of Whites and Blacks with knee osteoarthritis (OA).

METHODS

This cross-sectional study used baseline data of the OA Initiative, a national study of knee OA in the USA. This analysis included 4664 adults with knee OA, which was composed of 3790 White and 874 Black individuals. Annual income was the independent variable. Overweight/obesity status (body mass index more than 25 kg/m2) was the dependent variable. Race was the moderator. Logistic regressions were used for data analysis.

RESULTS

Overall, higher income was associated with lower odds of being overweight/obese. Race and income showed a statistically significant interaction on overweight/obesity status, indicating smaller protective effect of income for Blacks compared with Whites with knee OA. Race-stratified regression models revealed an inverse association between income and overweight/obesity for White but not Black patients.

CONCLUSIONS

While higher income protects Whites with knee OA against overweight/obesity, this effect is absent for Blacks with knee OA. Clinicians should not assume that the needs of high-income Whites and Blacks with knee OA are similar, as high-income Blacks may have greater unmet needs than high-income Whites. Racially tailored programs may help reduce the health disparities between Whites and Blacks with knee OA. The results are important given that elimination of racial disparities in obesity is a step toward eliminating racial gap in the burden of knee OA. This is particularly important given that overweight/obesity is not only a prognostic factor for OA but also a risk factor for cardiometabolic diseases and premature mortality.

Knee osteoarthritis risk in non-industrial societies undergoing an energy balance transition: evidence from the indigenous Tarahumara of Mexico

Non-industrial societies with low energy balance levels are expected to be less vulnerable than industrial societies to diseases associated with obesity including knee osteoarthritis. However, as non-industrial societies undergo rapid lifestyle changes that promote positive energy balance, individuals whose metabolisms are adapted to energetic scarcity are encountering greater energy abundance, increasing their propensity to accumulate abdominal adipose tissue and thus potentially their sensitivity to obesity-related diseases.

OBJECTIVES

Here, we propose that knee osteoarthritis is one such disease for which susceptibility is amplified by this energy balance transition.

METHODS

Support for our hypothesis comes from comparisons of knee radiographs, knee pain and anthropometry among men aged ≥40 years in two populations: Tarahumara subsistence farmers in Mexico undergoing the energy balance transition and urban Americans from Framingham, Massachusetts.

RESULTS

We show that despite having markedly lower obesity levels than the Americans, the Tarahumara appear predisposed to accrue greater abdominal adiposity (ie, larger abdomens) for a given body weight, and are more vulnerable to radiographic and symptomatic knee osteoarthritis at lower levels of body mass index. Also, proportionate increases in abdomen size in the two groups are associated with greater increases in radiographic knee osteoarthritis risk among the Tarahumara than the Americans, implying that the abdominal adipose tissue of the Tarahumara is a more potent stimulus for knee degeneration.

CONCLUSIONS

Heightened vulnerability to knee osteoarthritis among non-industrial societies experiencing rapid lifestyle changes is a concern that warrants further investigation since such groups represent a large but understudied fraction of the global population.

Geographical and ethnic differences of osteoarthritis-associated hip and knee replacement surgeries in New Zealand: a population-based cross-sectional study

OBJECTIVES

To (1) explore the regional and ethnic differences in rates of publicly funded osteoarthritis-associated hip and knee replacement surgeries and (2) investigate the mortality after surgery.

DESIGN

Population-based, retrospective, cross-sectional study.

SETTING

General population in New Zealand.

PARTICIPANTS

Patients with osteoarthritis who underwent publicly funded primary hip and knee replacement surgeries in 2005-2017. Patients aged 14-99 years were included.

PRIMARY AND SECONDARY OUTCOME MEASURES

Age-standardised rate, standardised mortality ratio (SMR) and 30 days, 90 days and 1 year mortality.

RESULTS

We identified 53 439 primary hip replacements and 50 072 primary knee replacements with a diagnosis of osteoarthritis. The number and age-standardised rates of hip and knee replacements increased over time. Māori had the highest age-standardised rate of hip replacements, followed by European/others and Pacific, and Asian had the lowest rate. Pacific had the highest age-standardised rate of knee replacements, followed by Māori and European/others, and Asian had the lowest rate. The Northern Health Network had the lowest rate of hip surgeries, and the Southern Health Network had the lowest rate of knee surgeries. The SMRs of patients undergoing hip and knee replacements were lower than the general population: 0.92 (95% CI 0.89 to 0.95) for hip and 0.79 (95% CI 0.76 to 0.82) for knee. The SMRs were decreasing over time. The patterns of 30 days, 90 days and 1 year mortality were similar to the SMR.

CONCLUSIONS

The numbers of publicly funded osteoarthritis-associated primary hip and knee replacements are steadily increasing. Māori people had the highest age-standardised rate of hip replacements and Pacific people had the highest rate of knee replacements. The Northern Health Network had the lowest rate of hip surgeries, and the Southern Health Network had the lowest rate of knee surgeries. Compared with the general population, patients who had hip and knee replacements have a better life expectancy.

Movement-evoked pain, physical function, and perceived stress: An observational study of ethnic/racial differences in aging non-Hispanic Blacks and non-Hispanic Whites with knee osteoarthritis

BACKGROUND

Knee osteoarthritis (OA) is a pervasive musculoskeletal condition, often exacerbated by movement-evoked pain (MEP). Despite established research demonstrating significant racial differences in OA pain, few studies have investigated ethnic/racial group differences in MEP and lower extremity function and their association with psychosocial factors, such as perceived stress. Therefore, the primary aims were: (1) to identify ethnic/racial group differences in persons with or at risk for knee OA pain based on MEP, physical performance, and perceived stress measures, and (2) to determine if perceived stress explains the relationship between MEP and function in non-Hispanic Blacks (NHBs) and non-Hispanic Whites (NHWs).

METHODS

A total of 162 NHB and NHW community-dwelling older adults (50-78 years of age) were included in this analysis from the Understanding Pain and Limitations in Osteoarthritic Disease (UPLOAD) cross-sectional cohort study. Demographic, anthropometric, pain and functional parameters were assessed using a battery of validated instruments. Descriptive statistics, parametric, and multivariate analyses were conducted to determine ethnic/racial differences in perceived stress, MEP, and function.

RESULTS

Our results support the hypothesis that among persons with knee OA pain, NHBs have significantly greater MEP and lower functional level, despite similar levels of perceived stress. However, perceived stress was more strongly related to MEP in NHB compared to NHWs. Differences in function were limited to walking speed, where NHWs demonstrated faster gait speed.

CONCLUSIONS

Our cross-sectional study demonstrated important ethnic/racial differences in MEP and function. Also, perceived stress had a stronger effect on MEP in NHBs, suggesting that perceived stress may more strongly influence pain with physical movement among NHB adults. MEP may be a clinically important pain outcome to measure in persons with OA, and these data warrant future research on the impact of stress on pain and functional outcomes in older adults, particularly in NHBs.

Translation, cross-cultural adaptation and validation of the traditional Chinese intermittent and constant osteoarthritis pain (ICOAP) questionnaire for knee osteoarthritis

OBJECTIVES

To translate and culturally adapt the Intermittent and Constant Osteoarthritis and Pain (ICOAP) measure to a traditional Chinese version, and to study its psychometric properties in patients with knee osteoarthritis (KOA).

METHOD

The ICOAP was translated and cross-culturally adapted into traditional Chinese according to the recommended international guidelines. A total of 110 participants with KOA in Hong Kong were invited to complete the traditional Chinese ICOAP (tChICOAP), the Chinese Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) pain subscale and the Chinese Short form of Health Survey (SF-12v2). Psychometric evaluations included content validity, construct validity, internal consistency and test and retest reliability.

RESULTS

All participants completed the tChICOAP questionnaire without missing items. The content validity index of all items ranged from 80% to 100%. The tChICOAP total pain and subscale scores had excellent internal consistency with Cronbach's alpha value (0.902-0.948) and good corrected item-total subscale correlations. It had high test and retest reliability (intra-class correlations 0.924-0.960). The tChICOAP constant, intermittent and total pain scores correlate strongly with the WOMAC pain subscale (r=0.671, 0.678 and 0.707, respectively, p<0.001). The tChICOAP intermittent and total scores correlate strongly with SF-12v2 physical component score (r=-0.590 and -0.558, respectively, p<0.001).

CONCLUSIONS

The tChICOAP is a reliable and valid instrument to measure the pain experience of Chinese patients with KOA.

Crossbow needle therapy of the Miao ethnic minority group for knee osteoarthritis: study protocol for a randomized controlled trial

BACKGROUND

Knee osteoarthritis (KOA) is commonly seen and has a high occurrence in the middle-aged and elderly. It is characterized by the degeneration and secondary bone hyperplasia of the articular cartilage; the pathologic changes are irreversible. Therefore, treatment of KOA is mainly focused on relieving pain, reducing inflammation, improving or restoring joint function, delaying disease progression, and increasing quality of life. Crossbow needle therapy of the Miao ethnic minority group is intended for KOA treatment and has been widely used. Studies of small sample size have seen significant improvement on pain relief, stiffness, and joint function.

METHODS/DESIGN

The trial is a randomized, multicenter, parallel, non-inferiority study. Three hundred and six patients will be randomly assigned to a crossbow needle group (n = 153) and an acupuncture group (n = 153). Patients in each group will receive treatment every other day, three times a week, 20 times in total. Follow-up will be conducted 15 days and 30 days after treatment. The primary outcome will be the Western Ontario and McMaster Osteoarthritis Index (WOMAC) score at baseline, the end of treatment, first follow-up, and second follow-up. The secondary outcomes will include Lysholm knee score, Japanese Orthopedic Association (JOA) knee score, visual analogue scale (VAS), and the MOS 36-item short-form health survey (SF-36).

DISCUSSION

The results of the trial will compare the efficacy on KOA between crossbow needle group and acupuncture group and will be expected to make a systematic and objective evaluation of crossbow needle therapy.

TRIAL REGISTRATION

ChiCTR, ChiCTR-INR-16008032 . Registered on 12 March 2016.

Comparison of patellar tracking according to different angles of external rotation of femoral component in varus knee of Asians

PURPOSE

Racial difference in the femoral geometry may exist. Asian femurs may be more externally rotated. If anatomical differences in distal femur had existed between Caucasians and Asians, the group with 5° external rotation of the femoral component should have shown better results than the group with 3° external rotation of the femoral component have.

METHODS

598 patients underwent total knee arthroplasty in our institution, among whom 83 patients (115 knees) who had postoperative computed tomography (CT) were studied retrospectively. Sixty-two knees were set in 5° of external rotation of femoral component relative to the posterior condylar axis (group A) while the others (53 knees) were set in 3° (group B). The femoral component rotation (FCR) was measured and compared using CT. The patellar tilting (PT) and the lateral patellar displacement (LPD) were measured to evaluate the patellar tracking using Merchant view. And postoperative clinical scores were compared.

RESULTS

The mean FCRs showed no significant difference between two groups ( p > 0.05). The mean PT and LPD showed no statistically significant difference either ( p > 0.05). There were no statistical differences in clinical scores.

CONCLUSION

The difference in the patellar tracking between the two groups could not be demonstrated. There were no statistical differences in clinical scores either. We concluded there is no need to adhere to 5° external rotation.

Radiographic Knee Osteoarthritis and Knee Pain: Cross-sectional study from Five Different Racial/Ethnic Populations

The weak correlation between pain and structural changes in knee osteoarthritis is widely reported. In a previous within-person, knee-matched case-control study among Caucasians, the severity of radiographic osteoarthritis (ROA) was strongly associated with both the presence of frequent knee pain and pain severity. We studied the association between ROA and knee pain in five racial/ethnic populations by using the same method. Subjects were selected from China; Japan; Korea and the United States. Among subjects with knees discordant for either frequent knee pain or pain severity, we examined the relationship between ROA and the presence of frequent knee pain using conditional logistic regression, and between ROA and pain severity using a stratified proportional odds model with an amalgamating conditional likelihood. In total, 252 urban Chinese, 221 rural Chinese, 297 Japanese, 122 Korean, 1,735 Caucasian, and 394 African-American patients were included. There was a strong dose-response relationship between the severity of ROA and the prevalence of frequent knee pain in all five racial/ethnic populations. Even mild ROA was significantly associated with frequent knee pain. In addition, ROA was also strongly associated with the severity of knee pain. These results show that structural pathology is associated with knee pain in different ethnic populations.

Depression and Pain in Asian and White Americans With Knee Osteoarthritis

Few studies have examined the underlying psychosocial mechanisms of pain in Asian Americans. Using the biopsychosocial model, we sought to determine whether variations in depression contribute to racial group differences in symptomatic knee osteoarthritis pain between Asian Americans and non-Hispanic white Americans. The sample consisted of 100 participants, including 50 Asian Americans (28 Korean Americans, 9 Chinese Americans, 7 Japanese Americans, 5 Filipino Americans, and 1 Indian American) and 50 age- and sex-matched non-Hispanic white Americans with symptomatic knee osteoarthritis pain. The Centers for Epidemiologic Studies Depression Scale was used to assess symptoms of depression, and the Western Ontario and McMaster Universities Osteoarthritis Index and the Graded Chronic Pain Scale were used to measure clinical pain. In addition, quantitative sensory testing was used to measure experimental sensitivity to heat- and mechanically-induced pain. The results indicated that higher levels of depression in Asian Americans may contribute to greater clinical pain and experimental pain sensitivity. These findings add to the growing literature regarding ethnic and racial differences in pain and its associated psychological conditions, and additional research is warranted to strengthen these findings.

PERSPECTIVE

This article shows the contribution of depression to clinical pain and experimental pain sensitivity in Asian Americans with knee osteoarthritis. Our results suggest that Asian Americans have higher levels of depressive symptoms and that depression plays a relevant role in greater clinical pain and experimental pain sensitivity in Asian Americans.

Polymorphisms in the Growth Differentiation Factor 5 (GDF 5) Gene in Knee Osteoarthritis

OBJECTIVE

To identify the frequency of the rs143383 SNPin the GDF5 gene, which is located in the 5'-untranslated region of Turkish population with knee osteoarthritis (OA).

STUDY DESIGN

Acase-control study.

PLACE AND DURATION OF STUDY

Orthopedics and Traumatology Department, Bozok University Medical Faculty, Yozgat, Turkey, from 2012 to 2014.

METHODOLOGY

Patients diagnosed with OA(n=94) and patients who did not have joint complaints (n=279) were enrolled in this study. Patients diagnosed with osteoarthritis according to the 1986 American College of Rheumatology osteoarthritis criteria and Kellgren and Lawrence scores were investigated, based on age, gender, and X-ray findings. Blood samples were taken for the identification of GDF5 (rs143383) SNPs by PCR/RFLP, according to a standard protocol.

RESULTS

This study included 373 patients. The OAgroup (25.2%; n=94) was characterized by specific genotypes: TT (39.4%; n=37); heterozygotes (TC; 45.7%; n=43); and homozygotes (CC; 14.9%; n=14). The control group (74.8%; n=279) was comprised of TT(26.5%; n=74), TC (54.8%; n=153), and CC (18.6%; n=52) genotypes. An analysis of rs143383 SNP of the GDF5 gene polymorphism revealed that the rs143383 TTgenotype had a higher risk for OA(crude OR=1.798, 95% CI=1.010-2.941, p=0.021).

CONCLUSION

This study demonstrated that there is a correlation of +104T/C polymorphism in the 5'-UTR of GDF5 with knee OAin a Turkish population.

Correlation of serum cartilage oligomeric matrix protein (COMP) and interleukin-16 (IL-16) levels with disease severity in primary knee osteoarthritis: A pilot study in a Malaysian population

Objective

The aim of this study was to investigate the correlations between serum cartilage oligomeric matrix protein (COMP), interleukin-16 (IL-16) and different grades of knee osteoarthritis (KOA) in Malaysian subjects.

Methods

Ninety subjects were recruited comprising 30 with Kellgren-Lawrence (K-L) grade 2 KOA, 27 with K-L grade 3 KOA, 7 with grade 4 KOA, and 30 healthy controls. All subjects completed the Western Ontario and McMaster Universities Arthritis Index (WOMAC) questionnaire. Serum COMP and IL-16 levels were measured using ELISA and their values log transformed to ensure a normal distribution.

Results

There was no significant differences in levels of log serum COMP and IL-16 between healthy controls and KOA patients. There were no significant differences in the log serum COMP and IL-16 levels within the different K-L grades in the KOA patients. In KOA patients, log serum IL-16 levels significantly correlated with the WOMAC score (p = 0.001) and its subscales, pain (p = 0.005), stiffness (p = 0.019) and physical function (p<0.0001). Serum IL-16 levels were significantly higher in Malaysian Indians compared to Malays and Chinese (p = 0.024).

Conclusions

In this multi-ethnic Malaysian population, there was no difference in serum COMP and IL-16 levels between healthy controls and patients with KOA, nor was there any difference in serum COMP or IL-16 levels across the various K-L grades of KOA. However, there were significant inter-racial differences in serum IL-16 levels.

Differences in Clinical Pain and Experimental Pain Sensitivity Between Asian Americans and Whites With Knee Osteoarthritis

OBJECTIVE

Ethnicity has been associated with clinical and experimental pain responses. Whereas ethnic disparities in pain in other minority groups compared with whites are well described, pain in Asian Americans remains poorly understood. The purpose of this study was to characterize differences in clinical pain intensity and experimental pain sensitivity among older Asian American and non-Hispanic white (NHW) participants with knee osteoarthritis (OA).

METHODS

Data were collected from 50 Asian Americans ages 45 to 85 (28 Korean, 9 Chinese, 7 Japanese, 5 Filipino, and 1 Indian) and compared with 50 age-matched and sex-matched NHW individuals with symptomatic knee OA pain. The Western Ontario and McMaster Universities Osteoarthritis Index and Graded Chronic Pain Scale were used to assess the intensity of clinical knee pain. In addition, quantitative sensory testing was used to measure experimental sensitivity to heat-induced and mechanically induced pain.

RESULTS

Asian American participants had significantly higher levels of clinical pain intensity than NHW participants with knee OA. In addition, Asian American participants had significantly higher experimental pain sensitivity than NHW participants with knee OA.

DISCUSSION

These findings add to the growing literature regarding ethnic and racial differences in clinical pain intensity and experimental pain sensitivity. Asian Americans in particular may be at risk for clinical pain and heightened experimental pain sensitivity. Further investigation is needed to identify the mechanisms underlying ethnic group differences in pain between Asian Americans and NHWs, and to ensure that ethnic group disparities in pain are ameliorated.

Effect of a Decision Aid on Access to Total Knee Replacement for Black Patients With Osteoarthritis of the Knee: A Randomized Clinical Trial

Importance

Black patients with advanced osteoarthritis (OA) of the knee are significantly less likely than white patients to undergo surgery. No strategies have been proved to improve access to surgery for black patients with end-stage OA of the knee.

Objective

To assess whether a decision aid improves access to total knee replacement (TKR) surgery for black patients with OA of the knee.

Design, Setting, and Participants

In a randomized clinical trial, 336 eligible participants who self-identified as black and 50 years or older with chronic and frequent knee pain, a Western Ontario McMaster Universities Osteoarthritis Index score of at least 39, and radiographic evidence of OA of the knee were recruited from December 1, 2010, to May 31, 2014, at 3 medical centers. Exclusion criteria were history of major joint replacement, terminal illness, inflammatory arthritis, prosthetic leg, cognitive impairment, lack of a telephone, or contraindications to elective replacement surgery. Data were analyzed on a per-protocol and intention-to-treat (ITT) basis.

Exposure

Access to a decision aid for OA of the knee, a 40-minute video that describes the risks and benefits of TKR surgery.

Main Outcomes and Measures

Receipt of TKR surgery within 12 months and/or a recommendation for TKR surgery from an orthopedic surgeon within 6 months after the intervention.

Results

Among 336 patients (101 men [30.1%]; 235 women [69.9%]; mean [SD] age, 59.1 [7.2] years) randomized to the intervention or control group, 13 of 168 controls (7.7%) and 25 of 168 intervention patients (14.9%) underwent TKR within 12 months (P = .04). These changes represent a 70% increase in the TKR rate, which increased by 86% (11 of 154 [7.1%] vs 23 of 150 [15.3%]; P = .02) in the per-protocol sample. Twenty-six controls (15.5%) and 34 intervention patients (20.2%) in the ITT analysis received a recommendation for surgery within 6 months (P = .25). The difference in the surgery recommendation rate between the controls (24 of 154 [15.6%]) and the intervention group (31 of 150 [20.7%]) in the per-protocol analysis also was not statistically significant (P = .25). Adjustment for study site yielded similar results: for receipt of TKR at 12 months, adjusted ORs were 2.10 (95% CI, 1.04-4.27) for the ITT analysis and 2.39 (95% CI, 1.12-5.10) for the per-protocol analysis; for recommendation of TKR at 6 months, 1.39 (95% CI, 0.79-2.44) and 1.41 (95% CI, 0.78-2.55).

Conclusions and Relevance

A decision aid increased rates of TKR among black patients. However, rates of recommendation for surgery did not differ significantly. A patient-centered counseling and educational intervention may help to address racial variations in the use of TKR for the management of end-stage OA of the knee.

Trial Registration

clinicaltrials.gov Identifer: NCT01851785.

IL1R1 gene polymorphisms are associated with knee osteoarthritis risk in the Chinese Han population

IL1R1, encoding interleukin 1 receptor type 1, is located in the IL-1 gene cluster and is involved in the pathogenesis of hand, hip, and knee osteoarthritis (OA) in different ethnicities. However, the link between IL1R1 polymorphisms and OA risk in the Chinese Han population is unknown. We studied the association between five IL1R1 polymorphisms (rs10490571, rs12712127, rs956730, rs3917225, and rs3917318) and OA risk by analyzing the genotypes of 298 knee OA patients and 297 controls using Sequenom MassARRAY technology. Logistic regression analysis after adjusting for gender and age revealed significant differences in the allele frequencies of IL1R1 rs956730 and IL1R1 rs3917225 between patients and controls. In addition, IL1R1 rs3917225 was associated with increased risk of knee OA with or without adjustment by age and gender in the dominant model (adjusted OR= 1.47, 95%CI: 1.04-2.07, P = 0.030), the recessive model (adjusted OR= 1.75, 95%CI: 1.08-2.85, P= 0.023), and the additive model (adjusted OR= 1.40, 95%CI: 1.09-1.79, P = 0.007). This study is the first to report that IL1R1 polymorphisms are associated with knee OA susceptibility in the Northwestern Chinese Han population.

Number of Persons With Symptomatic Knee Osteoarthritis in the US: Impact of Race and Ethnicity, Age, Sex, and Obesity

OBJECTIVE

The prevalence of symptomatic knee osteoarthritis (OA) has been increasing over the past several decades in the US, concurrent with an aging population and the growing obesity epidemic. We quantify the impact of these factors on the number of persons with symptomatic knee OA in the early decades of the 21st century.

METHODS

We calculated the prevalence of clinically diagnosed symptomatic knee OA from the National Health Interview Survey 2007-2008 and derived the proportion with advanced disease (defined as Kellgren/Lawrence grade 3 or 4) using the Osteoarthritis Policy Model, a validated simulation model of knee OA. Incorporating contemporary obesity rates and population estimates, we calculated the number of persons living with symptomatic knee OA.

RESULTS

We estimate that approximately 14 million persons had symptomatic knee OA, with advanced OA comprising more than half of those cases. This includes more than 3 million persons of racial/ethnic minorities (African American, Hispanic, and other). Adults younger than 45 years of age represented nearly 2 million cases of symptomatic knee OA and individuals between 45 and 65 years of age comprised 6 million more cases.

CONCLUSION

More than half of all persons with symptomatic knee OA are younger than 65 years of age. As many of these younger persons will live for 3 decades or more, there is substantially more time for greater disability to occur, and policymakers should anticipate health care utilization for knee OA to increase in the upcoming decades. These data emphasize the need for the deployment of innovative prevention and treatment strategies for knee OA, especially among younger persons.

Does a Patient-centered Educational Intervention Affect African-American Access to Knee Replacement? A Randomized Trial

BACKGROUND

A TKA is the most effective and cost-effective surgical option for moderate to severe osteoarthritis (OA) of the knee. Yet, black patients are less willing to undergo knee replacement surgery than white patients. Decision aids help people understand treatment options and consider the personal importance of possible benefits and harms of treatments, including TKA.

QUESTIONS/PURPOSES

We asked: (1) Does a patient-centered intervention consisting of a decision aid for knee OA and motivational interviewing improve the proportion of referrals of blacks with knee OA to orthopaedic surgery? (2) Does the intervention increase patients' willingness to undergo TKA?

METHODS

Adults who self-identified as black who were at least 50 years old with moderate to severe knee OA were enrolled from urban primary care clinics in a two-group randomized, controlled trial. A total of 1253 patients were screened for eligibility, and 760 were excluded for not meeting inclusion criteria, declining to participate, or other reasons. Four hundred ninety-three patients were randomized and completed the intervention; three had missing referral data at followup. The mean age of the patients was 61 years, and 51% were women. The majority had an annual household income less than USD 15,000. Participants in the treatment group were shown a decision-aid video and had a brief session with a trained counselor in motivational interviewing. Participants in the control group received an educational booklet about OA that did not mention joint replacement. The two groups had comparable demographic and socioeconomic characteristics. The primary outcome was referral to orthopaedic surgery 12 months after treatment exposure. Receipt of referral was defined as the receipt of a recommendation or prescription from a primary care provider for orthopaedic evaluation. The secondary outcome was change in patient willingness to undergo TKA based on patient self-report.

RESULTS

The odds of receiving a referral to orthopaedic surgery did not differ between the two study groups (36%, 90 of 253 of the control group; 32%, 76 of 240 of the treatment group; odds ratio [OR], 0.81; 95% CI, 0.56-1.18; p = 0.277). At 2 weeks followup, there was no difference between the treatment and the control groups in terms of increased willingness to consider TKA relative to baseline (34%, 67 of 200 patients in the treatment group; 33%, 68 of 208 patients in the control group; OR, 1.06; p = 0.779). At 12 months followup, the percent increase in willingness to undergo TKA still did not differ between patients in the treatment and control groups (29%, 49 of 174 in the treatment group; 27%, 51 of 191 in the control group; OR, 1.10; p = 0.679).

CONCLUSION

A combination decision aid and motivational interviewing strategy was no better than an educational pamphlet in improving patients' preferences toward joint replacement surgery for knee OA. The type of intervention treatment also did not affect access to surgical evaluation. Other tools that target patient knowledge, beliefs, and attitudes regarding surgical treatments for OA may be further developed and tested in the future.

LEVEL OF EVIDENCE

Level I, therapeutic study.

Predicting Satisfaction for Unicompartmental Knee Arthroplasty Patients in an Asian Population

BACKGROUND

Despite renewed interest in unicompartmental knee arthroplasty (UKA), there is a paucity of published literature with regard to patient satisfaction after UKA within Asian populations. The purpose of this study is to identify characteristics and factors which may contribute to patient dissatisfaction after UKA in a multiracial Asian population.

METHODS

Seven hundred twenty-four UKAs were performed between January 2007 and April 2013. Preoperative and postoperative variables were prospectively captured, such as standardized knee scores, knee range of motion, and patient satisfaction scores. These variables were then analyzed with a multiple logistic regression model to determine statistically significant factors contributing to patients' satisfaction.

RESULTS

Minimum duration of follow-up was 2 years, with an overall patient satisfaction rate of 92.2%. There was improvement in mean knee range of motion and across various standardized knee scores. Preoperative variables associated with patient dissatisfaction included a poorer preoperative Mental Component Summary, better preoperative knee extension, and better preoperative Oxford Knee Scores. Significant postoperative variables included better Oxford Knee Score at 6 months and Mental Component Summary at 2 years.

CONCLUSION

Despite the impressive patient satisfaction rate of UKA in this Asian population, these findings suggest that there is a targeted group of patients with select preoperative factors who would benefit from preoperative counseling.

Racial Differences in Serum Adipokine and Insulin Levels in a Matched Osteoarthritis Sample: A Pilot Study

BACKGROUND

In an attempt to correlate biomarkers with disease, serum-based biomarkers often are compared between individuals with osteoarthritis (OA) and control subjects. However, variable results have been reported. Some studies have suggested an association between certain adipokines and insulin and OA. We know that there are racial differences in OA prevalence and incidence, and from general population-based studies, those of Asian race consistently demonstrate a unique adipokine/insulin serum concentration profile as compared to Caucasians. Whether similar racial differences exist within OA samples is unknown and may have implications for selecting appropriate controls in comparative studies.

METHODS

Serum levels of adipokines, leptin, and adiponectin, along with insulin, were determined by ELISA in patients scheduled for total hip or knee replacement surgery for OA. Fifteen Asian patients were matched 1 : 1 on age (±2 years), gender, body mass index (±1.5 kg/m(2)), and surgical joint with Caucasian patients. Differences in serum concentrations were tested using paired t-tests.

RESULTS

Serum leptin and insulin levels were significantly higher in Asians compared to Caucasians (p < 0.05). While serum adiponectin levels were lower among Asians, the difference did not reach statistical significance (p = 0.12).

CONCLUSION

Findings from this work suggest that when studying serum biomarker concentrations in OA versus controls, race may be an important factor to consider. Our findings warrant confirmation in larger studies.

The impact of arthritis on the physical function of a rural Maya-Yucateco community and factors associated with its prevalence: a cross sectional, community-based study

This study aims to evaluate the impact of arthritis on the physical function of people living in a Maya-Yucateco rural community and to assess the association of known modifiable risk factors with the prevalence of overall arthritis and its main types (osteoarthritis and rheumatoid arthritis). Using a cross-sectional, community-based census design, data collected from the adult population (≥18 years) of the Municipality of Chankom, Yucatán, México, were analyzed (n = 1523). Participants’ physical function was assessed using a culturized version of the health assessment questionnaire disability index. Social, physical, and behavioral factors linked to overall arthritis, osteoarthritis, and rheumatoid arthritis, were assessed through the “Community-Oriented-Program-for-the-Control-of-Rheumatic-Diseases [COPCORD]” questionnaire. A physiatrist and a rheumatologist confirmed all osteoarthritis and rheumatoid arthritis cases using the American College of Rheumatology criteria. Arthritis was confirmed in 169 cases (22 %, 95 % confidence interval (CI) 19–25) of those assessed for musculoskeletal symptoms (n = 779): osteoarthritis = 144, rheumatoid arthritis = 17, and non-specific arthritis = 8. Arthritis was associated with a higher prevalence of disability after controlling for age, gender, and number of comorbidities (odds ratio = 4.0, 95 % CI 3.0–6.0). Higher level of wealth was associated with lower arthritis prevalence (odds ratio = 0.9, 95% CI 0.8–0.9). Higher body mass index was associated with higher hip and/or knee osteoarthritis prevalence (odds ratio = 1.1, 95 % CI 1.03–1.1). Arthritis is highly associated with disability in the Mayan people living in Chankom. The prevalence of arthritis in Chankom is associated with social factors, such as people’s level of wealth, while the prevalence of low-extremity osteoarthritis is associated with people’s body mass index.

Etoricoxib in the treatment of Korean patients with osteoarthritis in a double-blind, randomized controlled trial

OBJECTIVE

We evaluated the COX-2 inhibitors, etoricoxib and celecoxib, in Korean patients with osteoarthritis (OA).

METHODS

This study included patients (≥ 40 years of age) with a clinical and radiographic diagnosis of knee OA. Patients were randomized to etoricoxib 30 mg (qd) or celecoxib 200 mg (qd) in a 12 week randomized, controlled, double-blind study. Prior NSAID users were to demonstrate a worsening of symptoms upon withdrawal of medication. Efficacy endpoints included the time-weighted average change from baseline in the WOMAC VA 3.0 Pain Subscale (100 mm Visual Analog Scale [VAS]; primary endpoint), the WOMAC VA 3.0 Physical Function Subscale (100 mm VAS), and Patient Global Assessment of Disease Status (PGAD) (100 mm VAS). The primary hypothesis was that etoricoxib 30 mg is non-inferior to celecoxib 200 mg as assessed by the primary endpoint (the non-inferiority margin was set at 10 mm VAS). Adverse events (AEs), laboratory parameters, and vital signs were monitored.

RESULTS

There were 239 patients (89.5% female; mean age: 63.3 years) randomized to etoricoxib 30 mg (n = 120) and celecoxib 200 mg (n = 119). The differences (etoricoxib vs celecoxib) in least square (LS) mean change (95% CI) for WOMAC Pain, WOMAC Physical Function, and PGAD were -1.63 mm (-5.37, 2.10), -1.32 mm (-4.88, 2.23), and -1.09 mm (-5.48, 3.30), respectively. Drug-related clinical AEs occurred in 6.7% (etoricoxib) and 2.5% (celecoxib) of patients. This study was limited because it was not designed or powered to adequately capture and evaluate rare AEs associated with NSAID treatment.

CONCLUSIONS

Etoricoxib 30 mg administered once daily in Korean patients with knee OA demonstrated non-inferior clinical efficacy to celecoxib 200 mg over 12 weeks of treatment as assessed by all primary and secondary outcomes. Etoricoxib 30 mg qd and celecoxib 200 mg qd were generally safe and well tolerated.

CLINICAL TRIAL REGISTRATION

NCT01554163.

Racial disparities in knee and hip total joint arthroplasty: an 18-year analysis of national Medicare data

OBJECTIVE

To examine whether racial disparities in usage and outcomes of total knee and total hip arthroplasty (TKA and THA) have declined over time.

METHODS

We used data from the US Medicare Program (MedPAR data) for years 1991-2008 to identify four separate cohorts of patients (primary TKA, revision TKA, primary THA, revision THA). For each cohort, we calculated standardised arthroplasty usage rates for Caucasian and African-American Medicare beneficiaries for each calendar year, and examined changes in disparities over time. We examined unadjusted and adjusted outcomes (30-day readmission rate, discharge disposition etc.) for Caucasians and African-Americans, and whether disparities decreased over time.

RESULTS

In 1991, the use of primary TKA was 36% lower for African-Americans compared with Caucasians (20.6 per 10,000 for African-Americans; 32.1 per 10,000 for Caucasians; p<0.0001); in 2008, usage of primary TKA was 40% lower for African-Americans (41.5 per 10,000 for African-Americans; 68.8 per 10,000 for Caucasians; p<0.0001) with similar findings for the other cohorts. Black-White disparities in 30-day hospital readmission increased significantly from 1991-2008 among three patient cohorts. For example in 1991 30-day readmission rates for African-Americans receiving primary TKA were 6% higher than for Caucasians; by 2008 readmission rates for African-Americans were 24% higher (p<0.05 for change in disparity). Similarly, black-white disparities in the proportion of patients discharged to home after surgery increased across the study period for all cohorts (p<0.05).

CONCLUSIONS

In an 18-year analysis of US Medicare data, we found little evidence of declines in racial disparities for joint arthroplasty usage or outcomes.

Tibia vara affects the aspect ratio of tibial resected surface in female Japanese patients undergoing TKA

BACKGROUND

Tibia vara seen in Japanese patients reportedly influences the tibial component alignment when performing TKA. However, it is unclear whether tibia vara affects the component position and size selection.

QUESTIONS/PURPOSES

We therefore determined (1) the amount of medial tibial bow, (2) whether the tibia vara influences the aspect ratio of the tibial resected surface in aligning the tibial component with the tibial shaft axis, and (3) whether currently available tibial components fit the shapes of resected proximal tibias in terms of aspect ratio.

METHODS

We measured the tibia vara angle (TVA), proximal varus angle (PVA), and the mediolateral and middle AP dimensions of the resected surface using three-dimensional preoperative planning software in 90 knees of 74 female patients with varus osteoarthritis. We determined the correlations of the aspect ratio with TVA or PVA and compared the aspect ratios to those of five prosthesis designs.

RESULTS

The mean TVA and PVA were 0.6° and 2.0°, respectively. The aspect ratio negatively correlated with both TVA and PVA (r = -0.53 and -0.55, respectively). The mean aspect ratio of the resected surface was 1.48 but gradually decreased with increasing AP dimension, whereas four of the five prostheses had a constant aspect ratio.

CONCLUSIONS

The aspect ratio of resected tibial surface was inversely correlated to the degree of tibia vara, and currently available prosthesis designs do not fit well to the resected surface in terms of aspect ratio.

CLINICAL RELEVANCE

The design of a tibial component with a smaller aspect ratio could be developed to obtain better bone coverage in Japanese patients.

Development and validation of a new evaluation system for patients with a floor-based lifestyle: the Korean knee score

BACKGROUND

Patients' perspectives on functioning and health have been increasingly recognized as a crucial aspect of health care, leading to the use of patient-reported instruments for outcome assessment. However, available instruments for total knee arthroplasty do not reflect the floor-based lifestyle with high knee flexion of eastern Asia.

QUESTIONS/PURPOSES

We therefore (1) describe a novel patient-generated knee evaluation instrument, the Korean knee score (KKS), to reflect floor-based lifestyles with high knee flexion that included questions regarding health-related quality of life; (2) determined the reliability of the questionnaire; and (3) performed limited validation studies.

METHODS

The KKS was developed by a committee of 10 experts from 10 institutes nationwide. The development procedure comprised a development phase for generation of the questionnaire and a testing phase for assessment of measurement properties: reliability, validity, and responsiveness. A total of 634 patients participated in this test survey.

RESULTS

The KKS exhibited an intraclass correlation coefficient of 0.931 and internal consistency (Cronbach's α = 0.973). The absence of a ceiling or floor effect suggested content validity. The correlation coefficient with Knee Society score (knee score, function score) and Oxford knee score was 0.599, 0.690, and 0.871, respectively, suggesting construct validity. Correlation with concurrent measures of physical function from the SF-36 ranged from 0.549 to 0.719 and those of mental function from 0.407 to 0.428. Responsiveness was evident with a standardized response mean of 0.74.

CONCLUSIONS

The KKS is a reliable and responsive instrument for assessing osteoarthritis. The limited validation studies suggest it is an appropriate evaluation instrument for patients with osteoarthritis and a floor-based lifestyle.

The incidence of infrapatellar plicae in the elderly Welsh population

There are several studies reporting the incidence of suprapatellar, medial, and lateral plicae, but there is very limited information regarding the incidence of the infrapatellar plica. The purpose of our study was to record the incidence of infrapatellar plicae in the elderly Welsh population suffering from knee osteoarthritis. A prospective study was performed and 90 knees with severe osteoarthritis of the knee joint (Kellgren-Lawrence type III and IV) were investigated during total knee arthroplasty surgery. Documentation was performed at every total knee replacement surgery for the length of the study. Knee replacement was performed by one senior surgeon. Infrapatellar plica was investigated by a medial parapatellar approach and was classified into five types according to Kim's classification. The overall incidence of infrapatellar plicae was 37.7%. The most common type of plicae was the separate type (23.3%). There was no significant difference found between male and female patients. The fenestra type was the least common (2.22%). The incidence of infrapatellar plicae in the elderly Welsh population suffering from knee osteoarthritis was significantly lower when compared to a study that recorded the incidence of infrapatellar plica in young patients. Possibly, the degenerative changes of the knee joint can cause the resorption of the infrapatellar plica, thus decreasing its incidence in the elderly population.

Functional disabilities and satisfaction after total knee arthroplasty in female Asian patients

This study was conducted to investigate functional disabilities and patient satisfaction in Korean patients after total knee arthroplasty (TKA). Of 372 female patients who had undergone TKA with a follow-up longer than 12 months, 261 patients (70.2%) completed a questionnaire designed to evaluate functional disabilities, perceived importance, and patient satisfaction. The top 5 severe functional disabilities were difficulties in kneeling, squatting, sitting with legs crossed, sexual activity, and recreational activities. The top 5 in order of perceived importance were difficulties in walking, using a bathtub, working, recreation activities, and climbing stairs. Severities of functional disabilities were not found to be correlated with perceived importance. The 23 patients (8.8%) dissatisfied with their replaced knees had more severe functional disabilities than the patients satisfied for most activities. The dissatisfied patients tended to perceive functional disabilities in high-flexion activities to be more important than the satisfied.

Association of the calcitonin gene (CA) polymorphism with osteoarthritis of the knee in a Mexican mestizo population

Osteoarthritis (OA) is the most common form of destructive joint disease that is characterized by the degeneration of the articular cartilage, synovial membrane, joint capsule, and subchondral bone. The knee is a joint commonly affected for OA. Calcitonin (CT) has been suggested to have chondroprotective effects; therefore, could play a role in the pathogenesis of OA of the knee. Genetic variations in or adjacent to the CT gene may be associated with primary OA development. We conducted a case-control association study in which we examined the correlation between a dinucleotide (cytosine-adenine, CA) repeat polymorphism at the CT locus and OA of the knee in 88 patients with OA and in 111 control subjects from the Mexican mestizo population. Allele A and genotype AG frequencies were significantly higher in patients with OA than in control subjects (56.3 vs. 43.2%; p<0.001 and 40.9 vs. 26.1%; p=0.027, respectively), and were associated with the presence of OA of the knee (odds ratio [OR], 2.62; 95% confidence interval [95% CI], 1.30-5.27, and OR, 1.93; 95% CI, 1.04-3.58, respectively) using a logistic regression model adjusted for gender, age and Body mass index (BMI). The GG genotype was associated with a lower risk of OA development of the knee; thus, it may constitute a protective factor against this disease (OR, 0.40; 95% CI, 0.16-0.98). In summary, we conclude that the dinucleotide CA polymorphism in the CT gene may become a useful marker for genetic studies of OA of the knee in Mexican population.

Racial differences in osteoarthritis pain and function: potential explanatory factors

OBJECTIVE

This study examined factors underlying racial differences in pain and function among patients with hip and/or knee osteoarthritis (OA).

METHODS

Participants were n=491 African Americans and Caucasians enrolled in a clinical trial of telephone-based OA self-management. Arthritis Impact Measurement Scales-2 (AIMS2) pain and function subscales were obtained at baseline. Potential explanatory variables included arthritis self-efficacy, AIMS2 affect subscale, problem- and emotion-focused pain coping, demographic characteristics, body mass index, self-reported health, joint(s) with OA, symptom duration, pain medication use, current exercise, and AIMS2 pain subscale (in models of function). Variables associated with both race and pain or function, and which reduced the association of race with pain or function by >or=10%, were included in final multivariable models.

RESULTS

In simple linear regression models, African Americans had worse scores than Caucasians on AIMS2 pain (B=0.65, P=0.001) and function (B=0.59, P<0.001) subscales. In multivariable models race was no longer associated with pain (B=0.03, P=0.874) or function (B=0.07, P=0.509), indicating these associations were accounted for by other covariates. Variables associated with worse AIMS2 pain and function were: worse AIMS2 affect scores, greater emotion-focused coping, lower arthritis self-efficacy, and fair or poor self-reported health. AIMS2 pain scores were also significantly associated with AIMS2 function.

CONCLUSION

Factors explaining racial differences in pain and function were largely psychological, including arthritis self-efficacy, affect, and use of emotion-focused coping. Self-management and psychological interventions can influence these factors, and greater dissemination among African Americans may be a key step toward reducing racial disparities in pain and function.

Racial differences in gait mechanics associated with knee osteoarthritis

BACKGROUND AND AIMS

This study examines racial differences in gait mechanics in persons with knee osteoarthritis and the influence of anthropometrics, educational level, radiographic disease severity (rOA), and self-report measures of pain and disability on racial differences in gait.

METHODS

One hundred seventy five (64 black and 111 white) adults with radiographic knee OA were tested. 3-D kinematic and kinetic data were collected while subjects walked at two self-selected speeds (normal and fast). Anthropometric data, radiographic level of OA, and self-report measures of pain and disability were also collected. Gait patterns were compared across groups and within groups.

RESULTS

Black and white subjects did not differ significantly in radiographic OA. However, blacks walked significantly more slowly when asked to walk fast. At the normal speed, blacks had a smaller knee range of motion and loading rate than whites. Blacks also took longer to reach their peak maximum ground reaction force than whites. Within black subjects variations in gait mechanics were primarily explained by BMI, rOA, selfreported psychological disability, and pain self-efficacy. In white subjects, variations in gait mechanics were primarily explained by weight, age, velocity, psychological disability, and self-efficacy.

CONCLUSIONS

Blacks in this study had a pattern of gait mechanics generally associated with high levels of osteoarthritis, though they did not differ significantly in rOA from whites. The variability in gait patterns exhibited by blacks was most strongly related to variance in walking speed, anthropometrics, and perceived physical ability. Taken together, these results suggest that race is an important factor that must be considered in the treatment and study of osteoarthritis.

Failure of serum transforming growth factor-beta (TGF-beta1) as a biomarker of radiographic osteoarthritis at the knee and hip: a cross-sectional analysis in the Johnston County Osteoarthritis Project

PURPOSE

To assess associations between serum transforming growth factor-beta (TGF-beta1) and radiographic knee and hip osteoarthritis (rOA) in African American (AA) and White men and women.

METHODS

Baseline data from 330 participants in the Johnston County Osteoarthritis Project were used in the analysis. Radiographs were scored with the Kellgren-Lawrence scale and rOA defined as grade> or =2. Individual radiographic features (IRFs) were rated 0-3. TGF-beta1 was measured using a sandwich enzyme-linked immunosorbent assay (ELISA). General linear models were used to estimate associations between lnTGF-beta1 and rOA presence, laterality or severity, and IRF presence and severity, adjusting for age, gender, race and body mass index. Interactions by race and gender were considered significant at P<0.1.

RESULTS

Mean lnTGF-beta1 levels were higher among AAs compared to Whites, and among women compared to men (P<0.009). Mean lnTGF-beta1 levels were higher in those with knee osteophytes (OST), but this association was not significant after adjustment. There were no other significant differences in mean lnTGF-beta1 levels by presence, laterality, or severity of knee or hip rOA or IRFs. No race or gender interactions were identified, although a borderline significant association between lnTGF-beta1 and knee OST was seen among AAs (P<0.06).

CONCLUSIONS

Although serum TGF-beta1 varied by race and gender and several rOA variables, there were no independent significant associations with presence, laterality, or severity of knee or hip rOA by K-L grade or IRFs, suggesting that serum TGF-beta1 is unlikely to be useful as a stand-alone biomarker in OA studies. A possible association between TGF-beta1 and OST in AAs cannot be excluded.

Centers for Disease Control and Prevention (CDC). Racial disparities in total knee replacement among Medicare enrollees--United States, 2000-2006

An estimated 45% of U.S. adults might be at risk for developing symptomatic knee osteoarthritis during their lifetimes, with whites and blacks at equal risk for this common disabling condition. Total knee replacement (TKR) is an effective method of reducing pain and improving physical function among those with disabling knee osteoarthritis; however, whites have been more likely to undergo the procedure than blacks. As a result, a Healthy People 2010 objective calls for eliminating racial disparities in the rate of TKR among persons aged >/=65 years. To monitor progress toward achieving this objective, CDC analyzed national and state TKR rates for Medicare enrollees for the period 2000-2006, stratified by sex, age group, and black or white race. From 2000 to 2006, the TKR rate overall in the United States increased 58%, from 5.5 to 8.7 per 1,000 population, with similar increases among whites (61%) and blacks (56%). However, the TKR rate for blacks was 37% lower than the rate for whites in 2000 (3.6 versus 5.7 per 1,000 population) and 39% lower in 2006 (5.6 versus 9.2 per 1,000 population). Health-care providers and public health agencies might help reduce this disparity by widely distributing TKR information that is tailored to the education and literacy levels and culture of patients with symptomatic knee osteoarthritis. Health-care providers should conduct, as routine practice, thorough discussions regarding knee pain symptoms and loss of physical function with older patients of all races who might be candidates for TKR.

Ethnic differences in the relationship between obesity and joint pain and function in a joint arthroplasty population

OBJECTIVE

We investigated the influence of obesity on joint pain and function in Asians as compared to Caucasians with degenerative hip and knee arthritis.

METHODS

We surveyed 1983 patients (1876 Caucasians and 107 Asians) undergoing primary hip or knee replacement surgery. Relevant covariates including demographic data, body mass index (BMI), sex, comorbidities, education, and ethnicity were recorded. Pain and joint functional status were assessed at baseline and at 1-year followup with the Western Ontario and McMaster University Osteoarthritis Index (WOMAC) pain and function scores.

RESULTS

Asian patients presented for surgery at a significantly younger age and lower mean BMI, and reported greater pain and dysfunction than Caucasian patients. Multivariate linear regression modeling showed that for every level of BMI, Asian patients reported greater levels of joint pain and dysfunction. At a BMI of 30 kg/m2, this translated to a 16.6% higher WOMAC score (p < 0.001).

CONCLUSION

Among patients with endstage osteoarthritis, at every level of BMI, joint pain and dysfunction are greater in Asians than in Caucasians. This difference is likely mediated through both mechanical and inflammatory effects.

A study on indirect and intangible costs for patients with knee osteoarthritis in Singapore

OBJECTIVES

To estimate indirect costs through human capital approach and intangible costs through willingness-to-pay (WTP), and identify factors potentially affecting these costs in multiethnic Asian patients with knee osteoarthritis (OA).

METHODS

Data were collected through face-to-face interviews among knee OA patients. Human capital approach was used to estimate indirect costs by multiplying: 1) days of absence from work because of OA, with average earnings per capita per day for working patients; or 2) productivity loss with the market price of housekeeping for retirees/homemakers. A closed-ended iterative bidding contingent valuation method was used to elicit willingness-to-pay for a hypothetical cure of OA as a proxy for intangible costs. Mann-Whitney U or Kruskal-Wallis H-tests were performed in univariate analyzes, and linear regression in multivariate analyses.

RESULTS

Indirect costs per year and intangible costs were estimated at US$1008 and US$1200, accounting for 2.8% and 3.3% of annual household income, respectively. The indirect costs were significantly higher for male or working patients, while intangible costs were higher for Chinese, working patients, with higher income, or worse global well-being.

CONCLUSION

This study demonstrated that eliciting indirect costs through human capital approach and intangible costs through WTP are acceptable and feasible in Asian patients with knee OA. Besides the direct costs, the indirect and intangible costs for the OA patients could be substantial.

The growth differentiation factor 5 (GDF5) core promoter polymorphism is not associated with knee osteoarthritis in the Greek population

Genetic factors have been shown to play an important role in the etiology of osteoarthritis (OA). A functional single nucleotide polymorphism (SNP) +104T/C; rs143383 in the 5' UTR of the GDF5 gene was recently associated with susceptibility to osteoarthritis in the Japanese and Chinese population. Our objective was to assess whether this SNP was also associated with knee OA in a Greek Caucasian population sample. The +104T/C SNP was genotyped in a total of 519 case-control cohort; 251 patients with idiopathic knee OA and 268 controls were used. No significant differences were found in genotype or allele frequencies of the +104T/C SNP of GDF5 gene between cases and controls (p < 0.05). Also, no significant differences in allelic and genotypic frequencies were found when the individuals were stratified by sex. Our data implied that the +104T/C; rs143383 GDF5 core promoter polymorphism is not a risk factor for OA etiology in Greek Caucasians. Our study highlights the heterogeneous nature of OA genetic susceptibility.

Differences of self-reported osteoarthritis disability and race

BACKGROUND

Differences in self-reported disability may be found for older black and white adults with knee osteoarthritis (OA).

METHODS

This secondary analysis of data from a randomized single-blind clinical trial examined race differences in the relationship between self-reports and timed performance tests of walking. Study participants were 518 older adults (131 blacks, 387 whites), including 363 women and 155 men, with an average age of 68.6 years.

RESULTS

Older black and white adults with radiographically documented knee OA reported equivalent functional ability and pain severity. However, both blacks' OA severity rating and tested performance were significantly worse than those of whites. Self-report and tested walking performance were significantly less correlated among black older adults than among white older adults. Analyses of potential confounding variables documented that the difference was not due to marital status, gender, education, income, body mass index, comorbidity, pain level, OA severity or general health.

CONCLUSIONS

Self-reports of OA disability were less related to tested performance for walking among black older adults. Clinicians' knowledge of black patients' underestimation of their disability has compelling potential for improving clinical treatment and enhancing diagnostic approaches to care of older adults.

Development of a decision aid to address racial disparities in utilization of knee replacement surgery

OBJECTIVE

Previous studies suggest that poorer knowledge and expectations about surgical outcomes may be responsible for low rates of total knee replacement (TKR) among African American males. The goal of this study was to pilot test the scope, acceptability, and efficacy of an educational videotape and tailored TKR decision aid designed to reduce disparities in TKR knowledge and expectations.

METHODS

African American and Caucasian male veteran volunteers ages 55-85 years with moderate to severe knee osteoarthritis (OA) were recruited. During group meetings, patients viewed a video about knee OA treatments and were provided a personalized arthritis report that presented predicted patient outcomes should they decide to undergo TKR. Patients completed baseline and postintervention questionnaires that included an adapted Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) instrument to measure post-TKR expectations (0-100 scale with higher scores reflecting poorer outcomes).

RESULTS

A total of 102 patients (54 African American, 48 Caucasian) completed the baseline survey and 64 patients attended the intervention. There were no significant differences by race between patients completing and those dropping out of the study. At baseline (n = 102), African American patients expressed lower expectations about post-TKR outcomes than did Caucasian patients for both pain (WOMAC score 41 versus 34; P = 0.18) and physical function expectations (WOMAC score 38 versus 30; P = 0.13). Among African Americans who underwent the intervention, expected pain and physical function improved to 31 (P = 0.04 versus baseline) and 30 (P = 0.09 versus baseline), respectively. Caucasian patients' expectations changed little.

CONCLUSION

Disparities in baseline knowledge and expectations about TKR may be improved with the combined educational video and tailored decision aid.

Arthritis-specific health beliefs related to aging among older male patients with knee and/or hip osteoarthritis

BACKGROUND

Disease-specific beliefs may impact patients' perceptions of the efficacy of various treatment options, thus, it is important to understand these beliefs. We examined the relationship between patients' demographic characteristics and arthritis-specific beliefs related to aging.

METHODS

We performed a cross-sectional survey of 591 elderly primary care patients, who had symptomatic osteoarthritis (OA) of the knee and/or hip, at the Louis Stokes VA Medical Center in Cleveland, Ohio. Data were collected on age, race, educational level, income, and whether patients agreed or disagreed with four statements regarding aging and arthritis. We also assessed OA symptom severity using the Western Ontario McMaster Universities Index (WOMAC) and depressive symptoms using the Geriatric Depression Scale. We used logistic regression analyses to examine relationships between patients' age, race, and educational level and arthritis-specific health beliefs, while adjusting for OA symptom severity, radiographic confirmation of OA, OA joint burden, depressive symptoms, and income.

RESULTS

Patients 70 years old or older, as compared to patients 50-59 years old, were more likely to believe that: arthritis is a natural part of growing old; people should expect that when they get older, they won't be able to walk as well, and people should expect to live with pain as they grow older.

CONCLUSION

Among older, male veterans, health beliefs regarding the relationship between aging and arthritis vary by age. Clinicians should consider these differences when discussing treatment strategies with their patients with knee and/or hip OA.

Joint-specific hand symptoms and self-reported and performance-based functional status in African Americans and Caucasians: The Johnston County Osteoarthritis Project

OBJECTIVE

To assess associations between joint-specific hand symptoms and self-reported and performance-based functional status.

METHODS

Participants were from the population-based Johnston County Osteoarthritis Project. Symptoms in the distal interphalangeal (DIP), proximal interphalangeal (PIP), first carpometacarpal (CMC), and metacarpophalangeal (MCP) joints were assessed on a 30-joint diagram of both hands. Self-reported function was assessed by Health Assessment Questionnaire (HAQ) and performance-based function by timed repeated chair stands and 8-foot walk time. Separate multiple logistic regression models examined associations between symptoms in specific hand joint groups, symptoms in >/=2 hand joint groups and number of symptomatic hand joints, and functional status measures, controlling for age, race/ethnicity, sex, body mass index, radiographic knee and hip OA, knee and hip symptoms and depressive symptoms.

RESULTS

Those with symptomatic hand joint groups were more likely than those without these complaints to report more difficulty and require longer times for performance measures. Those with 2 or more symptomatic hand joint groups were more likely to have higher HAQ scores (OR = 1.97 (1.53 to 2.53)) and require more time to complete 5 chair stands (OR = 1.98 (1.23 to 3.18)) and the 8 foot walk test (OR = 1.49 (1.12 to 1.99)).

CONCLUSIONS

Joint-specific hand symptoms are associated with difficulty performing upper- or lower-extremity tasks, independent of knee and hip OA and symptoms, suggesting that studies examining functional status in OA should not ignore symptomatic joints beyond the joint site of interest, even when functional measures appear to be specific for the joint site under study.

"Keep on truckin'" or "It's got you in this little vacuum": race-based perceptions in decision-making for total knee arthroplasty

OBJECTIVE

Ethnic variation in the utilization of total knee arthroplasty (TKA) has been well documented, with African Americans showing significantly lower utilization rates. These differences are not explained by the prevalence or severity of knee osteoarthritis (OA). Patient preferences may contribute to differences in utilization since TKA is an elective surgery. We conducted a qualitative analysis of decision-making factors influencing ethnic preferences for TKA in patients with knee OA.

METHODS

Six focus group discussions were conducted with participants being divided according to race: 2 African American groups, 2 Hispanic groups, and 2 Caucasian groups. Participants were all patients with knee OA attending the same treatment facility. A total of 37 patients participated, 14 male and 23 female. Group discussions were led by a race-concordant facilitator. A grounded theory approach was used to analyze verbatim transcripts of the discussions.

RESULTS

Thirty distinct categories of information emerged in the analysis of the data. Four of these categories showed variation among ethnic groups and included explanations of illness, changes in lifestyle, trust and skepticism, and paying for surgery.

CONCLUSION

Patient attitudes and beliefs about TKA vary among ethnic groups. Differences in explanations of illness, changes in lifestyle, trust and skepticism, and paying for surgery are topics for discussion in the medical encounter. There is a need for open doctor-patient communication around individual experiences and beliefs in an effort to enhance decision-making for TKA.

Gender differences in pain and depressive tendency among Chinese elders with knee osteoarthritis

The purpose of this study was to explore gender differences in pain experiences, pain control beliefs, pain coping strategies, and depressive tendency among Chinese elderly with knee osteoarthritis (OA). Participants (N=199) were drawn from a previous convenience sample of outpatients with OA in Taiwan. Results indicated female elders tended to report higher scores on least pain, current pain and overall pain intensity than male elders (all p<0.01). Female elders also reported significantly greater pain disturbance than males across each item and for the overall score, except for walking. Males and females did not differ significantly in scores for pain control beliefs or for either pharmacological or non-pharmacological coping strategies. In addition, female elders tended to have greater depressive tendency than males. Results of regression analyses suggest that depressive tendency was a mediator of gender in predicting overall pain intensity and pain disturbance. In summary, this sample of elders showed gender differences in depressive tendency and some pain experiences but not in pain control beliefs and coping strategies. These results suggest that health care providers should be cautious about using gender differences to explain pain experiences among Chinese elders. In addition, health care providers may decrease these female patients' pain intensity and pain disturbance by treating depressive symptoms.

Risk factors for early radiographic changes of tibiofemoral osteoarthritis

OBJECTIVE

To evaluate the risk factors for early radiographic changes of knee osteoarthritis.

METHODS

SUBJECTS

(n = 114) with unilateral or bilateral grade 0-1 knee osteoarthritis underwent x ray examination of the knees (semiflexed anteroposterior view) and assessment with the Western Ontario and McMaster Universities (WOMAC) Osteoarthritis Index at baseline and 30 months later. Severity of joint space narrowing (JSN) and osteophytosis were graded in randomly ordered serial radiographs by two readers, blinded to the sequence of the films, using standard pictorial atlases.

RESULTS

The odds of an initial appearance of radiographic features of knee osteoarthritis at month 30 were more than threefold greater in African Americans than in whites (osteophytosis: odds ratio (OR) 3.30, 95% confidence interval (CI) 1.04 to 10.54; JSN: OR 3.49, 95% CI 1.16 to 10.68). In addition, the appearance of osteophytosis was positively related to baseline stiffness (OR 1.91/2.1 points on the 2-10 WOMAC scale, 95% CI 1.29 to 2.82).

CONCLUSIONS

The distinction between incident and established, but early, radiographic knee osteoarthritis is difficult because of the limits to which all possible evidence of the disease can be ruled out in a conventional baseline knee radiograph. Nonetheless, our finding that African Americans were at greater risk of early osteophytosis and JSN than other subjects differs from the results of our previous analysis of risk factors for progressive knee osteoarthritis in the same subjects. The development of osteophytes also was associated with joint stiffness. Future investigations should focus on the systemic and local influences that these ostensible risk factors represent.

Prevalence of knee symptoms and radiographic and symptomatic knee osteoarthritis in African Americans and Caucasians: the Johnston County Osteoarthritis Project

OBJECTIVE

To report contemporary estimates of the prevalence of knee-related osteoarthritis (OA) outcomes in African Americans and Caucasians aged > or = 45 years.

METHODS

Weighted prevalence estimates for knee symptoms, radiographic knee OA, symptomatic knee OA, and severe radiographic knee OA were calculated for age, ethnic, and sex subgroups, in 3018 participants (33% African Americans, 38% men) in the baseline examination (1991-97) of The Johnston County Osteoarthritis Project, a population-based study of OA in North Carolina. Radiographic knee OA was defined as Kellgren-Lawrence radiographic grade > or = 2, severe radiographic knee OA as grades 3 and 4, and symptomatic knee OA as knee symptoms in a knee with radiographic OA.

RESULTS

Knee symptoms were present in 43%, 28% had radiographic knee OA, 16% had symptomatic knee OA, and 8% had severe radiographic knee OA. Prevalence was higher in older individuals and women. African Americans had slightly higher prevalence of knee symptoms, radiographic knee OA, and symptomatic knee OA, but significantly higher prevalence of severe radiographic knee OA compared to Caucasians.

CONCLUSION

Policy should be directed to increasing education of the public and the medical community about the high prevalence of these conditions, especially in these subgroups, to decrease their impact and ultimately prevent them.

Musculoskeletal pain in Malaysia: a COPCORD survey

OBJECTIVE

To assess the nature and extent of rheumatic complaints in a semirural area in a multiracial (Malay, Indian, Chinese) community in Malaysia using the Community Oriented Program for the Control of Rheumatic Diseases (COPCORD) protocol initiated by ILAR and the WHO.

METHODS

All members of a community of 2700 persons over the age of 15 years were offered a questionnaire based interview in Phase 1 of the study. Those with rheumatic complaints (pain in the last 1 week) were invited for a physical examination by a rheumatologist in Phase 2.

RESULTS

In total, 2594 (96%) persons agreed to a questionnaire based interview. Of those interviewed, 21.1% had a current rheumatic complaint. The pain rate was higher in women (23.8%) than in men (17.8%). Chinese men had the lowest age-standardized pain rate (9.9%), while Indian women had the highest rate (28.4%). In the study population, 14.4% complained of pain in the joints and/or musculoskeletal pain and 11.6% had low back pain. The knee was responsible for 64.8% of all complaints pertaining to the joints, and more than half those examined with knee pain had clinical evidence of osteoarthritis (OA). The complaint rate increased with age, up to 53.4% in the group age > 65 years. The major disability encountered was the inability to squat (3.1%). Fibromyalgia, soft tissue lesions, and localized OA of the knees were the main clinical diagnoses. Inflammatory arthritis was uncommon. Both Western and traditional sources of healthcare were used, often together. Self-medication was common (58.8%).

CONCLUSION

Knee and back pain are the main rheumatic complaints in Malaysia, with complaint rates differing according to race and gender.

Variations in torsion of the lower limb in Japanese and Caucasians with and without knee osteoarthritis

OBJECTIVE

Associations between torsion of the lower limb and knee osteoarthritis (OA) appear to be inconsistent across populations. We examined whether femoral and tibiofibular torsion differed between people with and without knee OA (main effect), and whether the differences were consistent across Japanese and Australian Caucasian persons, and between women and men (interaction effect).

METHODS

Data collection was conducted in Japan and Australia. Subjects with knee OA included 100 Japanese and 102 Australian Caucasians, and healthy subjects included 52 Japanese and 34 Australian Caucasians. Femoral and tibiofibular torsion were measured using reliable clinical techniques. Three-way analysis of variance was conducted to examine the main and interaction effects.

RESULTS

While there were no significant differences in femoral and tibiofibular torsion between the subjects with and without knee OA as a whole (main effect), there were significant interactions (p < 0.05). Femoral antetorsion was lower only in the female subjects with knee OA compared with their healthy counterparts (p < 0.05). Tibiofibular torsion was lower only in the Japanese subjects with knee OA compared with their healthy counterparts (p < 0.01).

CONCLUSION

There may be ethnic and sex variations in the relationship between torsion of the lower limb and knee OA; and lower tibiofibular torsion can be a characteristic in a Japanese population with the disease. Longitudinal study is warranted to examine relationships between these variables and knee OA in a population-specific manner to determine whether the observed relationships express cause or effect.

Comparison of the EuroQol and short form 6D in Singapore multiethnic asian knee osteoarthritis patients scheduled for total knee replacement

OBJECTIVE

To compare the EuroQol (EQ-5D) and Short Form 6D (SF-6D) among multiethnic Asian patients with knee osteoarthritis (OA) scheduled for total knee replacement in Singapore.

METHODS

Patients were asked to complete questionnaires including the EQ-5D, Short Form 36, Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), and Lequesne knee index. EQ-5D and SF-6D utility scores were calculated using the scoring algorithms developed from the UK general population. Agreement between the 2 instruments was assessed by comparing their score distributions, means, medians, intraclass correlation coefficients (ICCs), and a Bland-Altman plot. Correlations of the EQ-5D and SF-6D with WOMAC and Lequesne knee index scores were also examined.

RESULTS

A consecutive sample of 258 knee OA patients (127 English-speaking and 131 Chinese-speaking) participated. The mean +/- SD EQ-5D utility score was 0.49 +/- 0.31 (range -0.25-1.00) and the mean SF-6D utility score was 0.63 +/- 0.12 (range 0.32-0.89). In a hypothetical example, this 0.14-point difference in mean utility scores yielded a difference of $10,000/quality-adjusted life year (QALY) in cost-effectiveness ratios. The score distribution was bimodal for the EQ-5D and normal for the SF-6D. This poor agreement was also demonstrated by the Bland-Altman plot and the low ICC (range 0.18-0.54). Correlations of the WOMAC and Lequesne index with the EQ-5D were higher than with the SF-6D.

CONCLUSION

Using different preference-based health-related quality of life instruments may yield different utility scores, which could have a great impact on QALY estimates. This highlights the importance of selecting appropriate instruments for economic evaluation. Additional research is needed to determine which instrument (the EQ-5D or the SF-6D) should be used in OA patients.

Who, when, and why total joint replacement surgery? The patient's perspective

PURPOSE OF REVIEW

Although total joint replacement is an effective treatment for advanced arthritis, many whom might benefit are unwilling to consider this procedure. This review highlights advances in understanding of patients' perceptions of total joint replacement.

RECENT FINDINGS

Research shows that patients' willingness to consider total joint replacement varies by sex, race/ethnicity, and socioeconomic status as a result of systematic differences in knowledge and beliefs about the procedure. Individuals with low socioeconomic status and minorities view the procedure less favorably than their wealthier, white counterparts, possibly partly explaining disparity in rates of use of the procedure among these groups. Among those undergoing total joint replacement, up to 30% experience a suboptimal outcome or are dissatisfied with results. Early work suggests that patients' expectations and self-efficacy are important potential predictors of postoperative outcome. Patient information needs regarding total joint replacement vary significantly and possibly systematically by sex and race/ethnicity. Available information materials may not address the concerns of many individuals contemplating the procedure, posing a potential barrier to surgery.

SUMMARY

Targeted culturally sensitive knowledge dissemination strategies are needed to improve the knowledge and beliefs of people with hip/knee arthritis about total joint replacement.

The influence of income and race on total knee arthroplasty in the United States

BACKGROUND

The associations among income, total knee arthroplasty, and underlying rates of knee osteoarthritis are not well understood. We studied whether high-income Medicare recipients are more likely to have a knee arthroplasty and less likely to suffer from knee osteoarthritis.

METHODS

Two data sources were used: (1) the 2000 United States Medicare claims data measuring the incidence of total knee arthroplasty by race, ethnicity, zip (postal) code income, and region (n = 27.5 million) and (2) the National Health and Nutrition Examination Survey (NHANES III) for individuals with an age of sixty years or more (n = 1926) with radiographic and clinical evidence of osteoarthritis. Logistic regression methods were used to adjust for covariates.

RESULTS

At the national level, age-adjusted rates of total knee arthroplasty in the high-income quintile were no higher than those in the low-income group (odds ratio, 0.98; 95% confidence interval, 0.96 to 1.00). Within regions, access to care was better for high-income groups (odds ratio, 1.19; 95% confidence interval, 1.17 to 1.22). Racial disparities in arthroplasty were significant (p < 0.001); the odds ratio was 0.36 (95% confidence interval, 0.34 to 0.38) for black men and 0.45 (95% confidence interval, 0.41 to 0.49) for Asian women. There was no evidence of an income gradient for most clinical and radiographic measures of arthritis. The exception was a significant negative association between income and pain on passive motion (p < 0.05).

CONCLUSIONS

High-income Medicare enrollees are no less likely to have osteoarthritis than low-income enrollees but have somewhat better access to care. Racial disparities are more important than those that are attributable to socioeconomic status.