Defining and mapping the person with osteoarthritis for population studies and public health

The effect of addition of dexamethasone into normal saline irrigation solution on Prevention of Intraperitoneal Adhesion Post Laparotomy in wistar rats (Rattus norvegicus)

INTRODUCTION

Intraperitoneal adhesion is a pathological condition of adhesion between the omentum, intestine and abdominal wall. The purpose of this study was to determine the effect of adding dexamethasone into normal saline fluid to prevent intra peritoneal adhesion.

MATERIALS AND METHODS

This study used experimental post-test only control group design. There were four treatment groups using six white rats in each group: group I without administration of normal saline and dexamethasone, group II with administration of normal saline irrigation, group III by adding dexamethasone dose 0.2 mg/BW into 5 cc normal saline, and group IV by adding 0.5 mg/BW into 5 cc normal saline. Laparotomy was performed to all samples followed by excoriation and abrasion in cecum and terminal ileum using gauze. Intra peritoneal adhesion assessment was carried out on the 10th day post laparotomy. Macroscopic and microscopic assessments were performed to evaluate formation of collagen, fibrin and the spread of inflammatory cells of each group.

RESULTS

From macroscopic observations, it was found that the average adhesion that occurred was 3.333; 2.333; 0.666; 0.333 by using statistical calculations with one-way ANOVA with P value of 0.000. Post-Hoc analysis showed that the administration of dexamethasone 0.5 mg/BW is proven to minimize the occurrence of adhesion between the 3 groups. Microscopic assessment of the formation of collagen, fibrin and the spread of inflammatory cells by one-way ANOVA produced P 0.000 in all three parameters, but the dose of dexamethasone administration between 0.2 mg/BW and 0.5 kg/BW did not prove significant in either group.

CONCLUSION

There is evidence that the addition of dexamethasone to normal saline as an irrigation liquid during laparotomy can reduce the occurrence of adhesion. However, the dose difference was not proven to be better in this study. Further studies are suggested to use more experimental animals.

Gene Expression Profiling Studies Using Microarray in Osteoarthritis: Genes in Common and Different Conditions

Osteoarthritis (OA), which is characterized mainly by cartilage degradation, is the most prevalent joint disorder worldwide. Although OA is identified as a major cause of joint pain, disability, and socioeconomic burden, the etiology of OA is still not clearly known. Recently, gene microarray analysis has become an efficient method for the research of complex diseases and has been employed to determine what genes and pathways are involved in the pathological process of OA. In this review, OA study results over the last decade are summarized for gene expression profiling of various tissues, such as cartilage, subchondral bone, and synovium in human OA and mouse OA models. Many differentially expressed genes, which mainly involve matrix metabolism, bone turnover, and inflammation pathways, were identified in diseased compared with "normal" tissues. Nevertheless, rare common genes were reported from studies using different tissue sources, microarray chips, and research designs. Thus, future novel and carefully designed microarray studies are required to elucidate underlying genetic mechanisms in the pathogenesis of OA as well as new directions for potential OA-targeted pharmaceutical therapies.

Reproductive history and osteoarthritis in the Women's Health Initiative

Objective: To investigate the relationship between self-reported osteoarthritis (OA) and reproductive factors in the Women's Health Initiative (WHI). Method: We used multivariable logistic regression to study the association of self-reported OA and reproductive factors in the WHI Observational Study and Clinical Trial cohorts of 145 965 postmenopausal women, in a retrospective cross-sectional format. Results: In our cohort, we observed no clinically significant associations between reproductive factors and OA given small effect sizes. The following factors were associated with statistically significant increased likelihood of developing OA: younger age at menarche (p < 0.001), history of hysterectomy [adjusted odds ratio (aOR) 1.013, 95% confidence interval (CI) 1.004-1.022, p = 0.04 vs no hysterectomy], history of unilateral oophorectomy (aOR 1.015, 95% CI 1.004-1.026, p < 0.01 vs no oophorectomy), parity (aOR 1.017, 95% CI 1.009-1.026, p < 0.001), ever use of oral contraceptives (aOR 1.008, 95% CI 1.001-1.016, p < 0.01 vs never use), and current use of hormonal therapy (reference current users, aOR 0.951, 95% CI 0.943-0.959 for never users; aOR 0.981, 95% CI 0.972-0.989 for past users; global p < 0.001). Age at menopause, first birth, and pregnancy were not associated with OA. Among parous women, no clear pattern was observed with number of pregnancies, births, or duration of breastfeeding in relation to OA. Conclusion: Our study showed that reproductive factors did not have significant clinical associations with OA after controlling for confounders. This may be due to complex hormonal effects. Additional investigation is warranted in prospective cohort studies. The Women's Health Initiative is registered under ClinicalTrials.gov. Trial registration ID: NCT00000611.

Spermidine activates RIP1 deubiquitination to inhibit TNF-α-induced NF-κB/p65 signaling pathway in osteoarthritis

Spermidine has been known to inhibit the production of pro-inflammatory cytokines. However, there are no reports about anti-inflammatory effects of spermidine on osteoarthritis (OA). Herein, we examined whether OA progression could be delayed by intraperitoneal injection (i.p.) of spermidine in the anterior cruciate ligament transection (ACLT) and TNF-α induced arthritis (TIA) mouse models. During the process, human FLS cells (H-FLS) were used to investigate the potential ubiquitination mechanism of spermidine-mediated RIP1 in TNF-α-induced NF-κB/p65 signaling. We found that spermidine attenuated synovitis, cartilage degeneration and osteophyte formation, resulting in substantially lower OARSI scores and TNF-α scores in spermidine-treated ACLT and TIA mice. In terms of the mechanism, 9 μM spermidine did not affect the viability, proliferation, cell cycle and apoptosis of H-FLS, and exerted inhibitory effects by activating CYLD-mediated RIP1 deubiquitination on TNF-α-induced NF-κB/p65 signaling in H-FLS. From these data, we can conclude that spermidine attenuates OA progression by the inhibition of TNF-α-induced NF-κB pathway via the deubiquitination of RIP1 in FLS. Therefore, intake of spermidine could be a potential therapy for preventing OA.

Longitudinal Assessment of Pain Management Among the Employed Japanese Population with Knee Osteoarthritis

Purpose

To assess comorbidity burden and pain-management patterns among working-aged patients with knee osteoarthritis only (KOA/O) and patients with knee osteoarthritis plus osteoarthritis at another site (KOA/+) in Japan.

Patients and Methods

Retrospective claims data analysis was conducted using the Japan Medical Data Center database. Working-aged adults (aged 40 to 71 years) with 5 years of follow-up and diagnosed with knee osteoarthritis (KOA) between January 1, 2011, and December 31, 2012, were evaluated. The first claim with a KOA diagnosis defined the index date. Patients were divided into two mutually exclusive cohorts: KOA/O and KOA/+. Longitudinal pain-management patterns during each year of follow-up were analyzed.

Results

A total of 2542 patients met study criteria: 1575 KOA/O and 967 KOA/+. Mean age and number of comorbidities were higher among the KOA/+ versus KOA/O cohort. Pharmaceutical treatment was received by 91.5% of patients in the KOA/+ compared with 85.1% of patients in the KOA/O cohort during the first year of follow-up. The most common pharmacological treatment received during the first year of follow-up was either topical or oral nonsteroidal anti-inflammatory drugs for both cohorts. During each year of follow-up, the KOA/+ cohort had greater proportion of patients with at least one health-care encounter (ie, hospital admissions, outpatient and pharmacy visits) and higher direct medical costs compared with the KOA/O cohort.

Conclusion

This study demonstrates that a greater proportion of the working population with KOA/+ received pain-related treatment compared with patients with KOA/O. Further studies are necessary to evaluate appropriate pain management for both KOA only and KOA with other sites.

MiR-1207-5p/CX3CR1 axis regulates the progression of osteoarthritis via the modulation of the activity of NF-κB pathway

BACKGROUND

Osteoarthritis (OA) is a prevalent chronic diseases characterized by formation of osteophytes and degradation of articular cartilage. Previous evidence has identified the regulatory effects of microRNAs (miRNAs) in OA. The goal of this study is to clearly explore the biological function of miR-1207-5p in OA.

METHODS

MiR-1207-5p and C-X3-C motif chemokine receptor 1 (CX3CR1) expression in OA cartilages were revealed by accessing to Gene Expression Omnibus database. In vitro OA model was established by lipopolysaccharide (LPS) stimulation. Western blot and quantitative real-time polymerase chain reaction were conducted to detect the expression level of genes. Cell counting kit-8 (CCK-8) and flow cytometric experiments were performed to investigate the proliferation and apoptosis capacities of CHON-001 cells. Bioinformatics analysis was applied to predict the binding site of miR-1207-5p and CX3CR1, the connections of which were ascertained using luciferase reporter assay.

RESULTS

MiR-1207-5p expression was decreased while CX3CR1 was increased in OA cartilages. Up-regulation of miR-1207-5p alleviated the LPS-induced damage in the view of cell proliferation, apoptosis and extracellular matrix (ECM) degradation. A target of miR-1207-5p CX3CR1, its down-regulation intensified the impacts of miR-1207-5p mimic, promoted proliferation and mitigated apoptosis. LPS exposure increased the protein expression of the phosphorylated IκBα and P65, and this phenomena was reversed due to miR-1207-5p up-regulation and CX3CR1 knockdown. The treatment of Betulinic acid (BA; an activator of nuclear factor-κB pathway) reversed the miR-1207-5p mimic-induced inhibitory effect on apoptosis in LPS-treated CHON-001.

CONCLUSION

Our results highlight that miR-1207-5p can prevent CHON-001 from LPS-stimulated injury, providing a novel biomarker for OA progression and further advancing treatment of OA.

Are OMERACT Knee Osteoarthritis Ultrasound Scores Associated With Pain Severity, Other Symptoms, and Radiographic and Magnetic Resonance Imaging Findings?

OBJECTIVE

To investigate the associations of Outcome Measures in Rheumatology (OMERACT) ultrasound scores for knee osteoarthritis (OA) with pain severity, other symptoms, and OA severity on radiographs and magnetic resonance imaging (MRI).

METHODS

Participants with symptomatic and mild to moderate radiographic knee OA underwent baseline dynamic ultrasound (US) assessment according to standardized OMERACT scanning protocol. Using the published US image atlas, a physician operator obtained semiquantitative or binary scores for US pathologies. Clinical severity was measured on numerical rating scale (NRS) and Knee Injury and Osteoarthritis Outcome Score (KOOS) symptoms and pain subscores. OA severity was assessed using the Kellgren-Lawrence (KL) grade on radiographs and MRI Osteoarthritis Knee Score (MOAKS) on noncontrast-enhanced MRI. Separate linear regression models were used to determine associations of US OA pathologies with pain and KOOS subscores, and Spearman correlations were used for US scores with KL grade and MOAKS.

RESULTS

Eighty-nine participants were included. Greater synovial hypertrophy, power Doppler (PD), and meniscal extrusion scores were associated with worse NRS pain [β 0.92 (95% CI 0.25-1.58), β 0.73 (95% CI 0.11-1.35), and β 1.01 (95% CI 0.22-1.80), respectively]. All greater US scores, except for cartilage grade, demonstrated significant associations with worse KOOS symptoms, whereas only PD and meniscal extrusion were associated with worse KOOS pain. All US scores, except for PD, were significantly correlated with KL grade. US pathologies, except for cartilage, revealed moderate to good correlation with their MOAKS counterparts, with US synovitis having the greatest correlation (0.69, 95% CI 0.60-0.78).

CONCLUSION

OMERACT US scores revealed significant associations with pain severity, KL grade, and MOAKS.

Macrophages regulate the progression of osteoarthritis

OA is now well accepted as a low-grade inflammatory disease affecting the whole joint. In addition to mechanical loading, inflammation (particularly synovitis), contributes significantly to OA. Synovial macrophages act as immune cells and are of critical importance in the symptomology and structural progression of OA. Activated macrophages are regulated by mTOR, NF-κB, JNK, PI3K/Akt and other signaling pathways, and are polarized into either M1 or M2 subtypes in OA synovial tissues, synovial fluid, and peripheral blood. The activation state and the M1/M2 ratio is highly associated with OA severity. Aside from autocrine interactions, paracrine interactions between macrophages and chondrocytes play a vital role in the initiation and development of OA by secreting inflammatory cytokines, growth factors, matrix metalloproteinases (MMPs) and tissue inhibitor of metalloproteinases (TIMPs), which lead to subsequent cartilage degradation and destruction. Treatments targeting synovial macrophages relieve pain, and protect from synovitis, cartilage damage, and osteophyte formation during OA development. Macrophage reprogramming of transformation from the M1 to M2 subtype, more than a decrease in the quantity of activated macrophages, appears to be an effective treatment option for OA. This review provides a broad understanding of the contributions of polarized macrophages to joint health and disease. Multifunctional agents with immunomodulatory effects on macrophage reprogramming can skew the inflammatory microenvironment towards a pro-chondrogenic atmosphere, and are thus, potential therapeutic options for the treatment of OA and other immune diseases.

The short-term efficacy of mud therapy for knee osteoarthritis: A meta-analysis

The objective of this review is to systematically evaluate the short-term efficacy of mud therapy in the treatment of knee osteoarthritis (KOA).Randomized controlled trials, in which treatment of KOA is mud therapy, were included by systematically searching the PubMed, Embase, and the Cochrane Library databases.According to inclusion criteria and searching method, 11 articles, containing a total of 1106 patients, were included in the study. Our results showed significant differences in visual analog scale pain score and Western Ontario and McMaster Universities Osteoarthritis Index (pain, stiffness, function). In addition, the heterogeneity of study included is lower (I < 25%).According to the results of this meta-analysis, mud therapy can effectively alleviate the pain and improve joint function for KOA.

Risk Factor Profiles for Individuals With Diagnosed OA and With Symptoms Indicative of OA: Findings From the Canadian Longitudinal Study on Aging

OBJECTIVE

The vast majority of published estimates of osteoarthritis (OA) burden are based on an OA diagnosis. These data are limited, as individuals often do not visit a physician until their symptoms are moderate to severe. This study compared individuals with an OA diagnosis to those with OA joint symptoms but without a diagnosis considering a number of sociodemographic and health characteristics. A further distinction was made between individuals with symptoms in one joint site and those with symptoms in multiple joint sites.

METHODS

Data are from 23 186 respondents aged 45 to 85 years from the first cycle of the Canadian Longitudinal Study on Aging. A multinomial logistic regression model examined the relationship between sociodemographic- and health-related characteristics and OA status (diagnosed OA, joint symptoms without OA, no OA or joint symptoms). In addition, logistic regression models assessed the relationship between OA status and usually experiencing pain and having some degree of functional limitation.

RESULTS

Twenty-one percent of respondents reported a diagnosis of OA, and 25% reported symptoms typical of OA but without an OA diagnosis. Other than being slightly younger, the characteristic profile of individuals with symptoms in two or more joint sites was indistinguishable from that of those with diagnosed OA.

CONCLUSION

It may be warranted to consider OA-like multiple joint symptoms when deriving estimates of OA-attributed population health and cost burden.

Do Knee Pain Phenotypes Have Different Risks of Total Knee Replacement?

Pain is the main impetus for osteoarthritis (OA) patients to seek healthcare including joint replacement. The pain experience in OA is heterogeneous and affected by factors across multiple domains—peripheral, psychological, and neurological. This indicates the existence of homogenous subgroups/phenotypes within OA patients with pain. We recently identified three pain phenotypes using a wide spectrum of pain-related factors, including structural damage on magnetic resonance imaging (MRI), emotional problems, number of painful sites, sex, body mass index, education level and comorbidities (i.e., Class 1: high prevalence of emotional problems and low prevalence of structural damage (25%); Class 2: low prevalence of emotional problems and high prevalence of structural damage (20%); Class 3: low prevalence of emotional problems and low prevalence of structural damage (55%)). This study was to examine whether the total knee replacement (TKR) risk over 12 years was different among these three pain phenotypes. Data on 963 participants (mean age 62.8 ± 7.4 years) from a population-based cohort study were utilised. Data on socio-demographic, psychological and comorbidities were collected. MRI of the right knee structural pathology was performed. TKR history was ascertained by linking to the Australian Orthopedic Association National Joint Replacement Registry. Latent class analysis and the Cox proportional hazards model were applied for the analysis. During the follow-up period, 41 right and 44 left TKRs in 67 participants were identified. In multivariable analyses, participants in Class 1 and 2 had a higher risk of having a TKR (Class 1 vs. Class 3, HR (hazard ratio) 4.81, 95%CI (confidence interval) 2.33–9.93; Class 2 vs. Class 3, HR 9.23, 95%CI 4.66–18.30). These associations were stronger in the imaged right knee but were also significant in the left knee. Participants within distinct pain phenotypes have different risks of TKR, suggesting that the identified phenotypes reflect distinct clinical subgroups with different prognoses. The risk for TKR was higher in Class 1 than that in Class 3, suggesting that pain/emotional status is a stronger driver for TKR than structural damage, and that selecting patients for TKR needs to be optimized in clinical practice.

Scaffold-Based Gene Therapeutics for Osteochondral Tissue Engineering

Significant progress in osteochondral tissue engineering has been made for biomaterials designed to deliver growth factors that promote tissue regeneration. However, due to diffusion characteristics of hydrogels, the accurate delivery of signaling molecules remains a challenge. In comparison to the direct delivery of growth factors, gene therapy can overcome these challenges by allowing the simultaneous delivery of growth factors and transcription factors, thereby enhancing the multifactorial processes of tissue formation. Scaffold-based gene therapy provides a promising approach for tissue engineering through transfecting cells to enhance the sustained expression of the protein of interest or through silencing target genes associated with bone and joint disease. Reports of the efficacy of gene therapy to regenerate bone/cartilage tissue regeneration are widespread, but reviews on osteochondral tissue engineering using scaffold-based gene therapy are sparse. Herein, we review the recent advances in gene therapy with a focus on tissue engineering scaffolds for osteochondral regeneration.

Osteoarthritis-related biomarkers profile in chronic anterior cruciate ligament injured knee

OBJECTIVE

Increasing evidence has shown the involvement of the innate immune system and inflammatory response in osteoarthritis (OA) pathogenesis; however, anterior cruciate ligament (ACL) tears are recognized risk factors for development of post-traumatic OA. We investigated (1) whether inflammatory mediators involved in OA pathogenesis are also present at significant concentrations in the knee joint sometime after ACL complete tear and may be considered as prognostic biomarkers of progression to secondary OA; and (2) whether quantification in serum may surrogate synovial fluid (SF) measurements in both cases.

METHODS

Thirty-seven end-stage OA patients and 33 patients with ACL complete tear that were included on the waiting list for knee surgery were consecutively recruited. Serum and SF samples were taken before surgery, and tumor necrosis factor-alpha, (TNF-α), interleukin-6 (IL-6), interleukin-8 (IL-8), matrix metalloproteinase-1 (MMP1), matrix metalloproteinase-3 (MMP3), tissue inhibitor of metalloproteinase-1 (TIMP1), bone morphogenetic protein-7 (BMP7), regulated upon activation normal t-cell expressed and secreted (RANTES), cytokine interferon-γ-induced protein 10 (IP-10) and heat shock protein family A (Hsp70) member 1A (HSPA1A) were quantified by enzyme-linked immunosorbent assay (ELISA.) Normally distributed data were compared using a one-way analysis of variance (ANOVA) test. Data not normally distributed were analyzed using a nonparametric Mann-Whitney rank sum test. Differences in means were compared using a Student's t-test. Correlations were analyzed using Pearson's coefficient of variation.

RESULTS

Eighty-seven percent of patients with OA and 86% of those with ACL tear had quantifiable levels of biomarkers in SF. SF levels of IL-6, IL-8, MMP1, MMP3, RANTES, IP-10, BMP7 and HSPA1A were significantly lower in ACL injury knees compared with those with OA, but much higher than those reported in control subjects. Serum levels of IL-6, IP-10, and MMP1 were also lower in patients with ACL tears, who had, however, significantly higher TNF-α, HSPA1A, and TIMP1 levels when compared with OA patients. Levels of biomarkers tested in serum and SF samples were significantly different.

CONCLUSIONS

Our data propose that cytokines IL-6 and IL-8 and the chemokines RANTES, IP-10, MMP1, MMP3, and HSPA1A may be involved in the inflammatory process leading to synovitis, the central lesion in OA onset and development; persistent high levels of these substances sometime after ACL injury suggest that they could play an etiopathogenic role in the maintenance of the inflammatory environment leading to post-traumatic OA. Serum biomarker levels do not appear to faithfully reflect what occurs inside the joint. Thus, most biomarkers cannot yet be considered as useful inflammatory biomarkers of knee joint diseases.

Development of an extensive assessment list for knee osteoarthritis based on the International Classification of Functioning, Disability and Health: a Delphi study

The objective of this study was to develop an extensive assessment list for individuals with knee osteoarthritis based on the International Classification of Functioning, Disability and Health (ICF) osteoarthritis comprehensive Core Set. Ten experienced physical therapists including five lecturers and five clinicians were purposively nominated to form an expert panel. Consensus among the experts was obtained through a four-iteration Delphi technique. A list of ICF categories and their third- and fourth-level categories were selected and matched with outcome measures associated with knee osteoarthritis. The expert panel agreed that 26 out of 38 second-level categories of the comprehensive ICF core set for osteoarthritis were relevant to identify problems related to knee osteoarthritis. The information relevant to the specific categories for knee osteoarthritis was obtained from self-reported, subjective observation and physical examination. The extensive assessment list for knee osteoarthritis based on the comprehensive ICF core set for osteoarthritis was assembled. This assessment tool can be used to expansively identify the multidimensional disabilities of impairment, activity limitation and participation restriction in individuals with knee osteoarthritis.

Differentiating knee pain phenotypes in older adults: a prospective cohort study

Objective

To identify and validate knee pain phenotypes in an older population across different pain-related domains over 10.7 years.

Methods

A total of 963 participants (mean age 63 years) from a population-based older adult cohort study were studied at baseline and followed up at 2.6 (n = 875), 5.1 (n = 768) and 10.7 years (n = 563). Baseline demographic, psychological, lifestyle and comorbidities data were obtained and MRI was performed to measure knee structural pathology. WOMAC pain and pain at multiple sites were assessed by questionnaires at each time-point. Latent class analysis was used to identify knee pain phenotypes, considering sex, BMI, emotional problems, education level, comorbidities, number of painful sites and knee structural pathology.

Results

Three pain phenotypes were identified: Class 1: high prevalence of emotional problems and low prevalence of structural damage (25%); Class 2: high prevalence of structural damage and low prevalence of emotional problems (20%); Class 3: low prevalence of emotional problems and low prevalence of structural damage (55%). Participants within Class 1 and 2 had greater BMI, more comorbidities, a higher prevalence of radiographic knee OA and knee structural pathology compared with Class 3. Furthermore, compared with Class 2 and 3, WOMAC pain and number of painful sites were consistently greater at each time-point over 10.7 years in Class 1. Results were similar when the analyses were restricted to participants with radiographic knee OA.

Conclusion

Psychological and structural factors interact with each other to exacerbate pain perception, suggesting that tailored treatment approaches for older people with knee pain in clinical practice are needed.

Ethnic differences in the prevalence, socioeconomic and health related risk factors of knee pain and osteoarthritis symptoms in older Malaysians

Knee pain is often underreported, underestimated and undertreated. This study was conducted to estimate the prevalence, burden and further identify socioeconomic factors influencing ethnic differences in knee pain and symptoms of OA among older adults aged 55 years and over in Greater Kuala Lumpur (the capital city of Malaysia). The sample for the Malaysian Elders Longitudinal Research (MELoR) was selected using stratified random sampling, by age and ethnicity from the electoral rolls of three parliamentary constituencies. Information on knee pain was available in 1226 participants, mean age (SD) 68.96 (1.57) years (409 Malay, 416 Chinese, 401 Indian). The crude and weighted prevalence of knee pain and self-reported knee OA symptoms were 33.3% and 30.8% respectively. There were significant ethnic differences in knee pain (crude prevalence: Malays 44.6%, Chinese 23.5% and Indians 31.9%, p<0.001). The presence of two or more non-communicable diseases (NCD) attenuated the increased risk of knee pain among the ethnic Indians compared to the ethnic Chinese. The prevalence of knee pain remained significantly higher among the ethnic Malays after adjustment for confounders. While the prevalence of knee pain in our older population appears similar to that reported in other published studies in Asia, the higher prevalence among the ethnic Malays has not previously been reported. Further research to determine potential genetic susceptibility to knee pain among the ethnic Malays is recommended.

KLF2 Protects against Osteoarthritis by Repressing Oxidative Response through Activation of Nrf2/ARE Signaling In Vitro and In Vivo

Osteoarthritis (OA) is a multifactorial and inflammatory disease characterized by cartilage destruction that can cause disability among aging patients. There is currently no effective treatment that can arrest or reverse OA progression. Kruppel-like factor 2 (KLF2), a member of the zinc finger family, has emerged as a transcription factor involved in a wide variety of inflammatory diseases. Here, we identified that KLF2 expression is downregulated in IL-1β-treated human chondrocytes and OA cartilage. Genetic and pharmacological overexpression of KLF2 suppressed IL-1β-induced apoptosis and matrix degradation through the suppression of reactive oxygen species (ROS) production. In addition, KLF2 overexpression resulted in increased expression of heme oxygenase-1 (HO-1) and NAD(P)H dehydrogenase quinone 1 (NQO1) through the enhanced nuclear translocation of nuclear factor erythroid 2-related factor 2 (Nrf2). Further, Nrf2 inhibition abrogated the chondroprotective effects of KLF2. Safranin O/fast green and TUNEL staining demonstrated that adenovirus-mediated overexpression of KLF2 in joint cartilage protects rats against experimental OA by inhibiting cartilage degradation and chondrocyte apoptosis. Immunohistochemical staining revealed that KLF2 overexpression significantly decreases MMP13 expression caused by OA progression in vivo. This in vitro and in vivo study is the first to investigate the antioxidative effect and mechanisms of KLF2 in OA pathogenesis. Our results collectively provide new insights into OA pathogenesis regulated by KLF2 and a rationale for the development of effective OA intervention strategies.

Viscoelasticity and histology of the human cartilage in healthy and degenerated conditions of the knee

BACKGROUND

There are many studies on osteoarthritis, but only a few studies deal with human arthrosis, comparing the mechanical properties of healthy and diseased samples. In most of these studies, only isolated areas of the tibia are examined. There is currently only one study investigating the complete mapping of cartilage tissue but not the difference between instantaneous modulus (IM) in healthy and diseased samples. The aim of this study is to investigate the relationship between the biomechanical and histological changes of articular cartilage in the pathogenesis of osteoarthritis.

METHODS

The study compared 25 tibiae with medial gonarthrosis and 13 healthy controls. The IM was determined by automated indentation mapping using a Mach-1 V500css testing machine. A grid was projected over the sample and stored so that all measurements could be taken at the same positions (100 ± 29 positions across the tibiae). This grid was then used to perform the thickness measurement using the needle method. Samples were then taken for histological examinations using a hollow milling machine. Then Giemsa and Safranin O staining were performed. In order to determine the degree of arthrosis according to histological criteria, the assessment was made with regard to Osteoarthritis Research Society International (OARSI) and AHO scores.

RESULTS

A significant difference (p < 0.05) could be observed in the measured IM between the controls with 3.43 ± 0.36 MPa and the samples with 2.09 ± 0.18 MPa. In addition, there was a significant difference in IM in terms of meniscus-covered and meniscus-uncovered areas. The difference in cartilage thickness between 2.25 ± 0.11 mm controls and 2.0 ± 0.07 mm samples was highly significant with p < 0.001. With regard to the OARSI and AHO scores, the samples differed significantly from the controls. The OARSI and AHO scores showed a significant difference between meniscus-covered and meniscus-uncovered areas.

CONCLUSIONS

The controls showed significantly better viscoelastic behavior than the arthrotic samples in the measured IM. The measured biomechanical values showed a direct correlation between histological changes and altered biomechanics in gonarthrosis.

Identification of key gene modules and transcription factors for human osteoarthritis by weighted gene co-expression network analysis

Osteoarthritis (OA) is one of the most prevalent causes of joint disease. However, the pathological mechanisms of OA have remained to be completely elucidated, and further investigation into the underlying mechanisms of OA development and the identification of novel therapeutic targets are urgently required. In the present study, the dataset GSE114007 was downloaded from the Gene Expression Omnibus database. Based on weighted gene co-expression network analysis (WGCNA) and the identification of differentially expressed genes (DEGs), the microarray data were further analyzed to identify hub genes, key transcription factors (TFs) and pivotal signaling pathways involved in the pathogenesis of OA. A total of 1,898 genes were identified to be differentially expressed between OA samples and normal samples. Based on WGCNA, the present study identified 5 hub modules closely associated with OA, and the potential key TFs for hub modules were further explored based on CisTargetX. The results demonstrated that B-Cell Lymphoma 6, Myelin Gene Expression Factor 2, Activating Transcription Factor 3, CCAAT Enhancer Binding Protein γ, Nuclear Factor Interleukin-3-Regulated, FOS Like Antigen-2, FOS-Like Antigen-1, Fos Proto-Oncogene, JunD Proto-Oncogene, Transcription Factor CP2 Like 1, RELA proto-oncogene NF-kB subunit, SRY-box transcription factor 3, V-Ets Avian Erythroblastosis Virus E26 Oncogene Homolog 2, Interferon Regulatory Factor 4 and REL proto-oncogene, NF-kB subunit were the potential key TFs. In addition, osteoclast differentiation, FoxO, MAPK and PI3K/Akt signaling pathways were revealed to be imperative for the pathogenesis of OA, as these 4 pivotal signaling pathways were observed to be tightly linked through 4 key TFs Fos Proto-Oncogene, JUN, JunD Proto-Oncogene and MYC, and 4 DEGs Vascular Endothelial Growth Factor A, Growth Arrest and DNA Damage Inducible α, Growth Arrest and DNA Damage Inducible β and Cyclin D1. The present study identified a set of potential key genes and signaling pathways, and provided an important opportunity to advance the current understanding of OA.

Early growth response 1 reduction in peripheral blood involving condylar subchondral bone loss

OBJECTIVES

To detect whether early growth response 1 (EGR1) in peripheral blood leucocytes (PBLs) indicates temporomandibular joint (TMJ) osteoarthritis (OA) lesions.

MATERIALS AND METHODS

Egr1 mRNA expression levels in PBLs were detected in eight malocclusion patients without temporomandibular disorder (TMD) signs and 16 malocclusion patients with clinical TMD signs with (eight) or without (eight) imaging signs of TMJ OA. Twelve 6-week-old rats were randomized to a control group and a unilateral anterior crossbite (UAC) group and were sampled at 4 weeks. The Egr1 mRNA expression levels in PBLs and protein expression levels in different orofacial tissues were measured.

RESULTS

Patients with TMD signs with/without TMJ OA diagnosis showed lower Egr1 mRNA expression levels in PBLs than patients without TMD signs. The lower Egr1 mRNA expression was also found in the PBLs of UAC rats, which were induced to exhibit early histo-morphological signs of TMJ OA lesions. In subchondral bone of UAC rats, EGR1 protein expression was decreased, co-localization of EGR1 with osterix or dentin matrix protein-1 was identified, and the number of EGR1 and osterix double-positive cells was reduced (all p < .05).

CONCLUSION

Egr1 reduction in PBLs potentially indicates subchondral bone OA lesions at an early stage.

Predictors of pain interference and potential gain from intervention in community dwelling adults with joint pain: A prospective cohort study

INTRODUCTION

There is little research on identifying modifiable risk factors that predict future interference of pain with daily activity in people with joint pain, and the estimation of the corresponding population attributable risk (PAR). The present study therefore investigated modifiable predictors of pain interference and estimated maximum potential gain from intervention in adults with joint pain.

METHODS

A population-based cohort aged ≥50 years was recruited from eight general practices in North Staffordshire, UK. Participants (n = 1878) had joint pain at baseline lasting ≥3 months and indicated no pain interference. Adjusted associations of self-reported, potentially modifiable prognostic factors (body mass index, anxiety/depressive symptoms, widespread pain, inadequate joint pain control, physical inactivity, sleep problems, smoking and alcohol intake) with onset of pain interference 3 years later were estimated via Poisson regression, and corresponding PAR estimates were obtained.

RESULTS

Inadequate joint-specific pain control, insomnia and infrequent walking were found to be independently significantly associated with the onset of pain interference after 3 years, with associated PARs of 6.3% (95% confidence interval -0.3, 12.4), 7.6% (-0.4, 15.0) and 8.0% (0.1, 15.2), respectively, with only the PAR for infrequent walking deemed statistically significant. The PAR associated with insomnia, infrequent walking and inadequate control of joint pain simultaneously was 20.3% (8.6, 30.4).

CONCLUSIONS

There is potential to reduce moderately the onset of pain interference from joint pain in the over-50s if clinical and public health interventions targeted pain management and insomnia, and promoted an active lifestyle. However, most of the onset of significant pain interference in the over-50s, would not be prevented, even assuming that these factors could be eliminated.

Interleukin-34 as a promising clinical biomarker and therapeutic target for inflammatory arthritis

Interleukin-34 (IL-34), recently identified as a novel inflammatory cytokine and the second ligand for colony-stimulating factor-1 receptor, is known to play regulatory roles in the development, maintenance, and function of mononuclear phagocyte lineage cells - especially osteoclasts. Regarding its primary effect on osteoclasts, IL-34 has been shown to stimulate formation and activation of osteoclasts, which in turn magnifies osteoclasts-resorbing activity. In addition to its role in osteoclastogenesis, IL-34 has been implicated in inflammation of synovium via augmenting production of inflammatory mediators, in which altered IL-34 expression is regulated by pro-inflammatory cytokines responsible for cartilage degradation. Indeed, IL-34 has been documented to be highly expressed in inflamed synovium of rheumatoid arthritis (RA) and knee osteoarthritis (OA) patients, which are recognized as inflammatory arthritis. Furthermore, a number of clinical studies demonstrated that IL-34 levels were significantly increased in the circulation and synovial fluid of patients with RA and knee OA. Its levels were also found to be positively associated with disease severity - especially radiographic severity of both RA and knee OA patients. Interestingly, emerging evidence has accumulated that functional blockage of IL-34 with specific antibody can alleviate the severity of inflammatory arthritis. It is therefore reasonable to speculate that IL-34 may be developed as a potential biomarker and a new therapeutic candidate for inflammatory arthritis. To date, there are numerous studies showing IL-34 involvement and association with many aspects of inflammatory arthritis. Herein, this review aimed to summarize the recent findings regarding regulatory role of IL-34 in synovial inflammation-mediated cartilage destruction and update the current comprehensive knowledge on usefulness of IL-34-based treatment in inflammatory arthritis - particularly RA and knee OA.

miR-21-5p protects IL-1β-induced human chondrocytes from degradation

OBJECTIVE

Osteoarthritis (OA) is a prevalent degenerative disease caused by various factors. MicroRNAs are important regulators in OA. MiR-21-5p expression is decreased in OA cartilage, but the effects of modulating miR-21-5p on cartilage regeneration are unknown. Therefore, our aim was to investigate the effects of miR-21-5p on cartilage metabolism of OA chondrocytes.

DESIGN

We used IL-1β (10 ng/ml) to mimic OA chondrocytes. OA chondrocytes were transfected with miR-21-5p, the gene expression of COL2A1, MMP13, and ADAMTS5 was detected by qPCR. At the same time, COL2A1, MMP13, and ADAMTS5 were analyzed at the protein level by Western blot. CCK8 measured the cell's viability and SA-β-gal detected the cell's senescence.

RESULTS

Upregulation of miR-21-5p had increased COL2A1 expression and decreased MM P13 and ADAMTS5 expression, which were in accord with Western blot data. SA-β-gal activity significantly increased, the viability was decreased in OA chondrocytes, and upregulation of miR-21-5p can decrease the SA-β-gal activity and increase cell viability.

CONCLUSION

MiR-21-5p might be a potential disease-modifying compound in OA, as it promotes hyaline cartilage production. These results provided that novel insights into the important function in OA pathological development.

Joint hypermobility is not positively associated with prevalent multiple joint osteoarthritis: a cross-sectional study of older adults

BACKGROUND

This cross-sectional study evaluated associations of joint hypermobility and multiple joint osteoarthritis (MJOA) in a community-based cohort of adults 45+ years of age.

METHODS

MJOA and joint hypermobility data were from 1677 participants (mean age 69 years, 68% women) who completed research clinic visits during 2003-2010. Prevalent MJOA was defined in four ways. Radiographic OA (rOA) was defined as Kellgren-Lawrence (KL) > 2 at any included study joint; symptomatic OA (sxOA) required both symptoms and rOA in a joint. Joint hypermobility was defined as a Beighton score of > 4. Separate logistic regression models were used to estimate odds ratios (OR) between joint hypermobility and each MJOA definition, adjusting for age, sex, race, body mass index, and baseline visit.

RESULTS

In this cohort, 4% had Beighton score > 4 and 63% met any definition of MJOA. Joint hypermobility was associated with significantly lower odds of radiographic and symptomatic MJOA-1 (multiple joint OA-definition 1: involvement of > 1 IP (interphalangeal) nodes and > 2 sites of hip, knee, and spine; 74 and 58% lower, respectively). However, for the other MJOA definitions (i.e., MJOA-2:involvement of > 2 IP joints, > 1 carpometacarpal [CMC] joints, and knee or hip sites; MJOA-3: involvement of > 5 joint sites from among distal interphalangeal, proximal interphalangeal, CMC, hip, knee, or spine sites; and MJOA-4:involvement of > 2 lower body sites (hip, knee, or spine), there were no statistically significant associations. For associations between site-specific hypermobility and any MJOA definition, most adjusted ORs were less than one, but few were statistically significant.

CONCLUSIONS

Overall, joint hypermobility was not positively associated with any definition of prevalent MJOA in this cohort, and an inverse association existed with one definition of MJOA. Longitudinal studies are needed to determine the contribution of hypermobility to the incidence and progression of MJOA outcomes.

Age- and Occupation-Based Public Health Considerations Related to Osteoarthritis of the Knee Joint: A Cadaveric Study

OBJECTIVE

Osteoarthritis (OA) literature makes minimal suggestion regarding age of disease onset or preventative strategies to reduce risk for onset in various populations. In 2005, the Centers for Disease Control and Prevention estimated that 33.6% of Americans 65+ years old were affected by OA; this cadaveric analysis suggests this is largely underestimated. The objective of this assessment is to identify at-risk populations for OA in the knee joint and make recommendations to prevent or delay disease onset.

DESIGN

Morphometric analyses of the articular cartilage of the tibial plateau were performed on cadaver specimens using Image Pro software on 3 age populations and surface area measurements for articular cartilage degradation were compared with donors' reported ages, clinical histories, and occupations.

RESULTS

Data showed that by the seventh decade of life, when patients are in their 60s, articular cartilage degeneration on the tibial plateau had commenced in 100% of specimen. All "homemakers" displayed above-average medial tibial plateau degeneration (32.33% ± 24.85%) for their age group while simultaneously reporting pathologies in their clinical history that encourage a sedentary lifestyle.

CONCLUSIONS

This assessment identifies an occupational class with a propensity to develop disease and also identifies a more realistic time frame than previous advisory committees have produced regarding age of disease onset and initiation of preventative measures. It is recommended that strengthening of the hip abductors and the musculature supporting the knee commence early in adult life to avoid valgus collapse and shearing at the knee joint.

Frailty Questionnaire Is Not a Strong Prognostic Factor for Functional Outcomes in Hip or Knee Arthroplasty Patients

Introduction

Up to 33% and 25% of patients with end-stage hip and knee osteoarthritis (OA) are considered frail by the Groningen Frailty Indicator (GFI). This study aims to assess whether frail patients have lower functional gains after arthroplasty and to assess GFI as a tool to discriminate between good and adverse change score.

Materials and Methods

Patients with end-stage hip/knee OA scheduled for arthroplasty were recruited from the Longitudinal Leiden Orthopaedics Outcomes of Osteo-Arthritis Study. Functional outcome was measured as change score on the Hip Osteoarthritis Outcome Score/Knee Osteoarthritis Outcome Score (HOOS/KOOS), by subtracting preoperative score from 1-year postsurgery score and then dichotomized based on a cutoff of 20 points. For each HOOS/KOOS subscale, 3 models were estimated: GFI univariate (model 1), GFI and baseline score (model 2), and baseline score univariate (model 3). A receiver operating characteristic analysis was performed to assess the discriminative ability of each model.

Results

Eight hundred five patients with end-stage hip OA (31.4% frail) and 640 patients with end-stage knee OA (25.4% frail) were included. Frail patients were older, had a higher body mass index, had more comorbidities, and lived more often alone. Persons considered frail by GFI had significant lower baseline score; however, except for "function in sports and recreation" and "quality of life," change scores were similar in frail and nonfrail persons. The discriminatory value of GFI was negligible for all HOOS/KOOS subscales. Baseline score, however, was adequate to discriminate between total knee arthroplasty patients with more or less than twice the minimally clinically important difference on KOOS symptoms subscale (area under the curve = 0.802).

Discussion/Conclusion

Although frail patients with OA have lower functioning scores at baseline, the change scores on HOOS/KOOS subscales are similar for both frail and nonfrail patients. Exploring other heath assessements may improve patient-specific outcome prediction.

Disease-modifying drugs in osteoarthritis: current understanding and future therapeutics

INTRODUCTION

Osteoarthritis (OA) is a leading cause of pain and disability among adults with a current prevalence of around 15% and a predicted prevalence of 35% in 2030 for symptomatic OA. It is increasingly recognized as a heterogeneous multi-faceted joint disease with multi-tissue involvement of varying severity. Current therapeutic regimens for OA are only partially effective and often have significant associated toxicities. There are no disease-modifying drugs approved by the regulatory bodies. Areas covered: We reviewed the opportunities within key OA pathogenetic mechanism: cartilage catabolism/anabolism, pathological remodeling of subchondral bone and synovial inflammation to identify targeted disease-modifying osteoarthritis drugs, based on compounds currently in Phase II and III stages of clinical development in which x-ray and/or MRI was used as the structural outcome with/without symptomatic outcomes according to regulatory requirements. Expert opinion: Given the heterogeneity of the OA disease process and complex overlapping among these phenotypes, a 'one size fits all' approach used in most clinical trials would unlikely be practical and equally effective in all patients, as well as in all anatomical OA sites. On the other hand, it is a challenge to develop a targeted drug with high activity, specificity, potency, and bioavailability in the absence of toxicity for long-term use in this chronic disease of predominantly older adults. Further research and insight into evaluation methods for drug-targeted identification of early OA and specific characterization of phenotypes, improvement of methodological designs, and development/refinement of sensitive imaging and biomarkers will help pave the way to the successful discovery of disease-modifying drugs and the optimal administration strategies in clinical practice.

Predictors of pain severity trajectory in older adults: a 10.7-year follow-up study

OBJECTIVES

To identify distinct pain trajectories over 10.7 years and to examine predictors of identified pain trajectories in an older population and those with radiographic knee osteoarthritis (ROA).

METHODS

963 participants (aged 50-80 years) from a population-based cohort had baseline demographic, psychological, lifestyle and comorbidities data collected. T1-and T2-weighted magnetic resonance imaging (MRI) of the right knee was performed to measure knee structural pathology-cartilage defects, bone marrow lesions (BMLs) and effusion-synovitis. Group-based trajectory modelling (GBTM) was applied to identify trajectories of knee pain over 10.7 years measured by Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC).

RESULTS

Three distinct pain trajectories were defined: 'Minimal pain' (n = 501, 52%), 'Mild pain' (n = 329, 34%) and 'Moderate pain' (n = 165, 14%). In multivariable analysis, having cartilage defects, BMLs and effusion-synovitis were associated with an increased risk of being in the 'Mild pain' (relative risk [RR]: 1.40 to 1.92) and 'Moderate pain' trajectory (RR: 1.72 to 2.26), compared with the 'Minimal pain' trajectory. Being obese and having more painful sites were associated with 'Mild pain' and 'Moderate pain' trajectories, while unemployment, lower education level and presence of emotional problems were associated with 'Moderate pain' trajectory group. Similar results were found for those with ROA.

CONCLUSION

Distinct pain trajectories identified suggest that homogeneous subgroups exist, which might be useful for phenotypic assessment for pain management, particularly in knee osteoarthritis. Structural pathology was associated with worse pain trajectories, suggesting that peripheral stimuli are critical for the development and maintenance of pain severity. Environmental and psychological factors may exacerbate pain perception.

Defining multiple joint osteoarthritis, its frequency and impact in a community-based cohort

BACKGROUND/PURPOSE

To update definitions of multiple joint osteoarthritis (MJOA), and to determine the frequency and impact of MJOA in a community-based cohort.

METHODS

Following PRISMA guidelines and with the help of a professional research librarian, we performed a systematic review in Medline using the terms osteoarthritis, generalized, polyarticular, multiple joint, and multi-joint among others, to obtain articles related to MJOA. A total of 42 articles were included for data extraction based on multiple criteria including the requirement for a clearly stated definition of OA assessed at more than one body site. We assessed frequency of these definitions in the Johnston County OA Project (JoCo OA) cohort as well as outcomes related to general health and physical function.

RESULTS

A total of 6 clearly stated definitions for MJOA were identified. These definitions were integrated with a list of 24 definitions from our previous systematic review and distilled down to produce 10 literature-derived, operationalized MJOA definitions. Based on these definitions, high frequencies of radiographic (4-74%) and symptomatic (2-52%) MJOA were found in the JoCo OA. Significant detrimental effects were seen on general health and physical function for most definitions.

CONCLUSIONS

We constructed a list of 10 summary MJOA definitions based in the literature that are frequent and associated with important clinical outcomes. These definitions capture some of the variability of MJOA phenotypes and provide a starting point for future analyses of both existing and newly initiated studies.

Whole exome sequencing in Finnish families identifies new candidate genes for osteoarthritis

INTRODUCTION

Osteoarthritis (OA) is the most common degenerative joint disease and one of the major causes of disability worldwide. It is a multifactorial disorder with a significant genetic component. The heritability of OA has been estimated to be 60% for hip OA and 39% for knee OA. Genetic factors behind OA are still largely unknown. Studying families with strong history of OA, facilitates examining the co-segregation of genetic variation and OA. The aim of this study was to identify new, rare genetic factors and novel candidate genes for OA.

METHODS

Eight patients from three Finnish families with hip and knee OA were studied using whole exome sequencing. We focused on rare exonic variants with predicted pathogenicity and variants located in active promoter or strong enhancer regions. Expression of identified candidate genes were studied in bone and cartilage tissues and the observed variants were investigated using bioinformatic analyses.

RESULTS

Two rare variants co-segregated with OA in two families. In Family 8 a missense variant (c.628C>G, p.Arg210Gly) was observed in the OLIG3 gene that encodes a transcription factor known to be associated with rheumatoid arthritis and inflammatory polyarthritis. The Arg210Gly variant was estimated to be pathogenic by Polyphen-2 and Mutation taster and the locus is conserved among mammals. In Family 12 the observed variant (c.-127G>T) was located in the transcription start site of the FIP1L1 gene. FIP1L1 participates in the regulation of polyadenylation. The c.-127G>T is located in the transcription start site and may alter the DNA-binding of transcription factors. Both, OLIG3 and FIP1L1 were observed in human bone and cartilage.

CONCLUSION

The identified variants revealed novel candidate genes for OA. OLIG3 and FIP1L1 have specific roles in transcription and may effect expression of other genes. Identified variants in these genes may thus have a role in the regulatory events leading to OA.

Uptake of the NICE osteoarthritis guidelines in primary care: a survey of older adults with joint pain

Background

Osteoarthritis (OA) is a leading cause of pain and disability. NICE OA guidelines (2008) recommend that patients with OA should be offered core treatments in primary care. Assessments of OA management have identified a need to improve primary care of people with OA, as recorded use of interventions concordant with the NICE guidelines is suboptimal in primary care. The aim of this study was to i) describe the patient-reported uptake of non-pharmacological and pharmacological treatments recommended in the NICE OA guidelines in older adults with a self-reported consultation for joint pain and ii) determine whether patient characteristics or OA diagnosis impact uptake.

Methods

A cross-sectional survey mailed to adults aged ≥45 years (n = 28,443) from eight general practices in the UK as part of the MOSAICS study. Respondents who reported the presence of joint pain, a consultation in the previous 12 months for joint pain, and gave consent to medical record review formed the sample for this study.

Results

Four thousand fifty-nine respondents were included in the analysis (mean age 65.6 years (SD 11.2), 2300 (56.7%) females). 502 (12.4%) received an OA diagnosis in the previous 12 months. More participants reported using pharmacological treatments (e.g. paracetamol (31.3%), opioids (40.4%)) than non-pharmacological treatments (e.g. exercise (3.8%)). Those with an OA diagnosis were more likely to use written information (OR 1.57; 95% CI 1.26,1.96), paracetamol (OR 1.30; 95% CI 1.05,1.62) and topical NSAIDs (OR 1.30; 95% CI 1.04,1.62) than those with a joint pain code. People aged ≥75 years were less likely to use written information (OR 0.56; 95% CI 0.40,0.79) and exercise (OR 0.37; 95% CI 0.25,0.55) and more likely to use paracetamol (OR 1.91; 95% CI 1.38,2.65) than those aged < 75 years.

Conclusion

The cross-sectional population survey was conducted to examine the uptake of the treatments that are recommended in the NICE OA guidelines in older adults with a self-reported consultation for joint pain and to determine whether patient characteristics or OA diagnosis impact uptake. Non-pharmacological treatment was suboptimal compared to pharmacological treatment. Implementation of NICE guidelines needs to examine why non-pharmacological treatments, such as exercise, remain under-used especially among older people.

Does a Program Based on Cognitive Behavioral Therapy Affect Kinesiophobia in Patients Following Total Knee Arthroplasty? A Randomized, Controlled Trial With a 6-Month Follow-Up

BACKGROUND

To evaluate the effects of a cognitive behavioral therapy (CBT) program on kinesiophobia, knee function, pain and pain catastrophizing in patients following total knee arthroplasty (TKA).

METHODS

This was a parallel-group, randomized, controlled pilot study in which 100 patients who exhibited kinesiophobia after TKA were randomly assigned to participate in a CBT (experimental group) or standard care (control group) program. Each group included 50 patients. Before intervention (preintervention), 4 weeks after intervention (postintervention), and 6 months after the end of intervention (follow-up), patients were assessed via the Tampa Scale for Kinesiophobia, the Pain Catastrophizing Scale, a numerical rating scale, and the Hospital for Special Surgery knee rating scale. Repeated-measures analysis of variance was used to test the significance of each outcome measure.

RESULTS

The CBT program had significant group (P < .001), time (P < .001), and group-by-time interaction (P < .001) effects on kinesiophobia, pain catastrophizing, and knee function, and these effects lasted for at least 6 months after the end of the intervention. Pain was reduced in both groups after the intervention, but there were significant time and group effects (P = .003) in favor of the experimental group.

CONCLUSION

The CBT program was superior to standard care in reducing kinesiophobia, pain catastrophizing, and knee pain and in enhancing knee function in patients who have a high level of kinesiophobia following TKA. The treatment effect was clinically significant and lasted for at least 6 months after the end of the intervention.

Enhancing delivery of osteoarthritis care in the general practice consultation: evaluation of a behaviour change intervention

BACKGROUND

Professionally-focussed behaviour change intervention (BCI) workshops were utilised in the Management of OsteoArthritis in Consultations (MOSAICS) trial investigating the feasibility of implementing the National Institute for Health and Care Excellence (NICE) Osteoarthritis (OA) Guideline in general practice. The workshops aimed to implement the general practitioner (GP) component of the trial intervention: an enhanced consultation for patients presenting with possible OA. This study presents an evaluation of the BCI workshops on GP competency in conducting these enhanced consultations.

METHODS

A before-and-after evaluation of the workshops, delivered to GPs participating in the intervention arm of the MOSAICS trial, using video-recorded GP consultations with simulated OA patients. GPs attended four workshops, which had been developed using an implementation framework. Videos were undertaken at three time-points (before workshops and at one- and five-months after) and were assessed by independent observers, blinded to time points, for GP competency in undertaking 14 predetermined consultation tasks.

RESULTS

Videos of 15 GPs were assessed. GP competency increased from a median of seven consultation tasks undertaken by each GP at baseline to 11 at both time-points after the workshops. Specific tasks which were undertaken more frequently after the workshops related to explaining that OA is treatable and not inevitably progressive, eliciting and addressing patient expectations of the consultation, and providing written OA information. However, the use of the word "osteoarthritis" in giving the diagnosis of OA was not enhanced by the workshops.

CONCLUSIONS

BCI workshops can enhance GP competency in undertaking consultations for OA. Further initiatives to implement the NICE OA Guideline and enhance the care of people with OA in primary care can be informed by the content and delivery of the workshops evaluated in this study.

Genetic correction of adipose tissue-derived mesenchymal stem cells mediated by TALEN targeting the GDF5 gene

Stem cells and other associated cell types may be a potential alternative to treat various genetic disorders that currently do not benefit from traditional approaches. Functional recovery of cells could be induced via directional differentiation or genetic manipulation. In this study, mesenchymal stem cells (MSCs) were obtained from a patient with osteoarthritis (OA) carrying a functional single‑nucleotide polymorphism (SNP rs143383, C/T transition) within the 5'‑UTR of growth and differentiation factor 5 (GDF5) gene. The SNP causes GDF5 expression to be reduced and thus increases OA susceptibility. Aiming to correct the dysfunctional gene, a pair of transcription activator‑like effector nucleases (TALENs) were designed to cleave the DNA around the mutated locus, coupled with a short single stranded DNA complementary to the cleavage site. Following in vitro cell colony formation and selection, two genetically corrected MSC colonies were identified out of a total of 142. These MSCs were induced and differentiated into chondrocytes. As a result, genetically corrected chondrocytes exhibited normal morphology and lower levels of apoptosis compared with cells carrying the SNP. In cultured cells, the secretion of matrix metalloproteinases was suppressed and TIMP metallopeptidase inhibitor 1 was increased by correction of the mutation. Furthermore, the expression of GDF5 target genes, cell vitality‑associated genes and extracellular matrix degrading genes were returned to normal levels in corrected cells compared with mutation‑carrying cells, indicating the functional recovery of these corrected chondrocytes. The present study demonstrated that TALEN‑mediated genetic correction can be used to edit genes in adipose‑derived MSCs from patients with OA and may have clinical potential.

Identification of genes and pathways in the synovia of women with osteoarthritis by bioinformatics analysis

Osteoarthritis (OA) has a high prevalence in female patients and sex may be a key factor affecting the progression of OA. The aim of the present study was to identify genetic signatures in the synovial membranes of female patients with OA and to elucidate the potential associated molecular mechanisms. The gene expression profiles of the GSE55457 and GSE55584 datasets were obtained from the Gene Expression Omnibus database. Data of two synovial membranes from normal female individuals (GSM1337306 and GSM1337310) and two synovial membranes from female patients affected by OA (GSM1337327 and GSM1337330) were obtained from the dataset GSE55457, and those of three synovial membranes from female patients affected by OA (GSM1339628, GSM1339629 and GSM1339632) were obtained from the dataset GSE55584. Differentially expressed genes (DEGs) were identified by using Morpheus software. Protein-protein interaction (PPI) networks of the DEGs were constructed by using Cytoscape software. Subsequently, Gene Ontology (GO) function and Kyoto Encyclopaedia of Genes and Genomes (KEGG) pathway enrichment analyses of the top module of the PPI network were performed by using ClueGo. A total of 377 DEGs were identified in the synovial membranes of OA patients compared with those of normal individuals, including 164 upregulated and 213 downregulated genes. The top 10 hub genes were ubiquitin (UB)C, ribosomal protein (RP) L23A, mammalian target of rapamycin, heat shock protein 90 α family class A member 1, RPS28, RPL37A, RPS24, RPS4X, RPS18 and UBB. The results of the GO analysis indicated that the DEGs included in the top module of the PPI were mainly enriched in the terms ‘nuclear-transcribed mRNA catabolic process’, ‘nonsense mediated decay’, and ‘cytoplasmic translation and ribosomal small subunit biogenesis’. KEGG pathway analysis indicated that the DEGs included in the top one module were mainly enriched in the ‘ribosome’ pathway. The present study provides a systematic, molecular-level understanding of the degeneration of the synovial membrane in the progression of OA in female patients. The hub genes and molecules associated with the synovial membrane may be used as biomarkers and therapeutic targets for the treatment of OA in female patients with OA.

Osteoarthritis: Trauma vs Disease

Osteoarthritis (OA) is the most prevalent joint disease characterized by pain and degenerative lesions of the cartilage, subchondral bone, and other joint tissues. The causes of OA remain incompletely understood. Over the years, it has become recognized that OA is a multifactorial disease. In particular, aging and trauma are the main risk factors identified for the development of OA; however, other factors such as genetic predisposition, obesity, inflammation, gender and hormones, or metabolic syndrome contribute to OA development and lead to a more severe outcome. While this disease mainly affects people older than 60 years, OA developed after joint trauma affects all range ages and has a particular impact on young individuals and people who have highest levels of physical activity such as athletes. Traumatic injury to the joint often results in joint instability or intra-articular fractures which lead to posttraumatic osteoarthritis (PTOA). In response to injury, several molecular mechanisms are activated, increasing the production and activation of different factors that contribute to the progression of OA.In this chapter, we have focused on the interactions and contribution of the multiple factors involved in joint destruction and progression of OA. In addition, we overview the main changes and molecular mechanisms related to OA pathogenesis.

Diagnostic value of combined serum marker changes and quantitative MRI evaluation of cartilage volume of tibial plateau in a surgically-induced osteoarthritis dog model

Objective

To evaluate the combined diagnostic value of two serum osteoarthritis (OA) markers and quantitative magnetic resonance imaging (MRI) evaluation of the cartilage volume of the tibial plateau in a canine model of experimental OA.

Methods

A total of 18 male Beagle dogs were used in this longitudinal study. OA was surgically induced via anterior cruciate ligament transection (ACLT) of the right knee in 10 dogs. The remaining eight dogs formed the sham operation control group and underwent the same procedure without ACLT. At various times after surgery, enzyme-linked immunosorbent assay was used to measure serum C-telopeptide of type II collagen (CTX-II) and type X collagen (ColX) levels. Quantitative evaluation of the tibial plateau volume was undertaken using MRI and ImageJ software.

Results

The serum CTX-II levels were significantly higher in the OA group at weeks 8, 12 and 16 after surgery, but not at week 4, compared with the control group. The serum ColX levels in the OA group were significantly higher than in the control group at weeks 8 and 12. The tibial plateau cartilage volumes in the OA group were significantly lower than in the control group at weeks 8 and 16.

Conclusion

Serum CTX-II and ColX levels combined with quantitative MRI evaluation of the tibial plateau cartilage volume in a canine model of OA demonstrated the potential to detect and monitor OA progression.

Running and Knee Osteoarthritis: A Systematic Review and Meta-analysis

BACKGROUND

Osteoarthritis (OA) is a chronic condition characterized by pain, impaired function, and reduced quality of life. A number of risk factors for knee OA have been identified, such as obesity, occupation, and injury. The association between knee OA and physical activity or particular sports such as running is less clear. Previous reviews, and the evidence that informs them, present contradictory or inconclusive findings.

PURPOSE

This systematic review aimed to determine the association between running and the development of knee OA.

STUDY DESIGN

Systematic review and meta-analysis.

METHODS

Four electronic databases were searched, along with citations in eligible articles and reviews and the contents of recent journal issues. Two reviewers independently screened the titles and abstracts using prespecified eligibility criteria. Full-text articles were also independently assessed for eligibility. Eligible studies were those in which running or running-related sports (eg, triathlon or orienteering) were assessed as a risk factor for the onset or progression of knee OA in adults. Relevant outcomes included (1) diagnosis of knee OA, (2) radiographic markers of knee OA, (3) knee joint surgery for OA, (4) knee pain, and (5) knee-associated disability. Risk of bias was judged by use of the Newcastle-Ottawa scale. A random-effects meta-analysis was performed with case-control studies investigating arthroplasty.

RESULTS

After de-duplication, the search returned 1322 records. Of these, 153 full-text articles were assessed; 25 were eligible, describing 15 studies: 11 cohort (6 retrospective) and 4 case-control studies. Findings of studies with a diagnostic OA outcome were mixed. Some radiographic differences were observed in runners, but only at baseline within some subgroups. Meta-analysis suggested a protective effect of running against surgery due to OA: pooled odds ratio 0.46 (95% CI, 0.30-0.71). The I² was 0% (95% CI, 0%-73%). Evidence relating to symptomatic outcomes was sparse and inconclusive.

CONCLUSION

With this evidence, it is not possible to determine the role of running in knee OA. Moderate- to low-quality evidence suggests no association with OA diagnosis, a positive association with OA diagnosis, and a negative association with knee OA surgery. Conflicting results may reflect methodological heterogeneity. More evidence from well-designed, prospective studies is needed to clarify the contradictions.

Synovitis in osteoarthritis: current understanding with therapeutic implications

Modern concepts of osteoarthritis (OA) have been forever changed by modern imaging phenotypes demonstrating complex and multi-tissue pathologies involving cartilage, subchondral bone and (increasingly recognized) inflammation of the synovium. The synovium may show significant changes, even before visible cartilage degeneration has occurred, with infiltration of mononuclear cells, thickening of the synovial lining layer and production of inflammatory cytokines. The combination of sensitive imaging modalities and tissue examination has confirmed a high prevalence of synovial inflammation in all stages of OA, with a number of studies demonstrating that synovitis is related to pain, poor function and may even be an independent driver of radiographic OA onset and structural progression. Treating key aspects of synovial inflammation therefore holds great promise for analgesia and also for structure modification. This article will review current knowledge on the prevalence of synovitis in OA and its role in symptoms and structural progression, and explore lessons learnt from targeting synovitis therapeutically.

Systemic inflammation and painful joint burden in osteoarthritis: a matter of sex?

OBJECTIVE

We investigated the association between serum levels of C-reactive protein (CRP) and the extent of multijoint pain among individuals with hip/knee osteoarthritis (OA) and determined whether the association differs by sex.

DESIGN

Serum CRP and cartilage oligomeric matrix protein (COMP) were determined by enzyme-linked immunosorbent assay (ELISA) in 189 individuals (101 female, 88 male) scheduled for total hip/knee arthroplasty for OA. Patients indicated on a homunculus all painful joints; a summed count was derived. A series of negative binomial regression models was used to investigate the cross-sectional association between painful joint count (outcome) and serum CRP concentrations, adjusting for age, sex, body mass index (BMI), comorbidity count and COMP. An interaction between sex and these biomarkers was tested.

RESULTS

Mean age: 66 among women, 65 among men. Women had higher mean joint count (3.7 vs 2.5, P < 0.01; 4+ joint count reported by 37% women, 25% men). Median CRP concentration was higher in women (15.4 mg/l vs 9.3, P = 0.07). From adjusted analyses, the effects of both ln(CRP) and ln(COMP) were modified by sex (P < 0.05). Increasing ln(CRP) was associated with greater painful joint count among women, but not men.

CONCLUSIONS

There may be a dose-response association between painful joint burden in OA and systemic inflammation, and it appears the association is sex-specific, which may in part explain inconsistent findings in the literature. Our results underline the importance of showing sex-specific associations in OA, especially when studying the influence of inflammation.

The quality-of-life burden of knee osteoarthritis in New Zealand adults: A model-based evaluation

BACKGROUND

Knee osteoarthritis is a leading global cause of health-related quality of life loss. The aim of this project was to quantify health losses arising from knee osteoarthritis in New Zealand (NZ) in terms of quality-adjusted life years (QALYs) lost.

METHODS

The Osteoarthritis Policy Model (OAPol), a validated Monte Carlo computer simulation model, was used to estimate QALYs lost due to knee osteoarthritis in the NZ adult population aged 40-84 over their lifetimes from the base year of 2006 until death. Data were from the NZ Health Survey, NZ Burden of Diseases, NZ Census, and relevant literature. QALYs were derived from NZ EQ-5D value set 2. Sensitivity to health state valuation, disease and pain prevalence were assessed in secondary analyses.

RESULTS

Based on NZ EQ-5D health state valuations, mean health losses due to knee osteoarthritis over people's lifetimes in NZ are 3.44 QALYs per person, corresponding to 467,240 QALYs across the adult population. Average estimated per person QALY losses are higher for non-Māori females (3.55) than Māori females (3.38), and higher for non-Māori males (3.34) than Māori males (2.60). The proportion of QALYs lost out of the total quality-adjusted life expectancy for those without knee osteoarthritis is similar across all subgroups, ranging from 20 to 23 percent.

CONCLUSIONS

At both the individual and population levels, knee osteoarthritis is responsible for large lifetime QALY losses. QALY losses are higher for females than males due to greater prevalence of knee osteoarthritis and higher life expectancy, and lower for Māori than non-Māori due to lower life expectancy. Large health gains are potentially realisable from public health and policy measures aimed at decreasing incidence, progression, pain, and disability of osteoarthritis.

Reconsultation, self-reported health status and costs following treatment at a musculoskeletal Clinical Assessment and Treatment Service (CATS): a 12-month prospective cohort study

OBJECTIVES

To determine (1) reconsultation frequency, (2) change in self-reported health status, (3) baseline factors associated with reconsultation and change in health status and (4) associated healthcare costs and quality-adjusted life-years (QALYs), following assessment at a musculoskeletal Clinical and Assessment Treatment Service (CATS).

DESIGN

Prospective cohort study.

SETTING

Single musculoskeletal CATS at the primary-secondary care interface.

PARTICIPANTS

2166 CATS attenders followed-up by postal questionnaires at 6 and 12 months and review of medical records.

OUTCOME MEASURES

Primary outcome was consultation in primary care with the same musculoskeletal problem within 12 months. Secondary outcome measures were consultation at the CATS with the same musculoskeletal problem within 12 months, physical function and pain (Short Form-36), anxiety and depression (Hospital Anxiety and Depression Scale), time off work, healthcare costs and QALYs.

RESULTS

Over 12 months, 507 (38%) reconsulted for the same problem in primary care and 345 (26%) at the CATS. Primary care reconsultation in the first 3 months was associated with baseline pain interference (relative risk ratio 5.33; 95% CI 3.23 to 8.80) and spinal pain (1.75; 1.09 to 2.82), and after 3-6 months with baseline assessment by a hospital specialist (2.06; 1.13 to 3.75). Small mean improvements were seen in physical function (1.88; 95% CI 1.44 to 2.32) and body pain (3.86; 3.38 to 4.34) at 6 months. Poor physical function at 6 months was associated with obesity, chronic pain and poor baseline physical function. Mean (SD) 6-month cost and QALYs per patient were £422.40 (660.11) and 0.257 (0.144), respectively.

CONCLUSIONS

While most patients are appropriate for a 'one-stop shop' model, those with troublesome, disabling pain and spinal pain commonly reconsult and have ongoing problems. Services should be configured to identify and address such clinical complexity.

Recent advances in the understanding of molecular mechanisms of cartilage degeneration, synovitis and subchondral bone changes in osteoarthritis

Osteoarthritis (OA), the most common form of degenerative joint disease, is linked to high morbidity. It is predicted to be the single greatest cause of disability in the general population by 2030. The development of disease-modifying therapy for OA currently face great obstacle mainly because the onset and development of the disease involve complex molecular mechanisms. In this review, we will comprehensively summarize biological and pathological mechanisms of three key aspects: degeneration of articular cartilage, synovial immunopathogenesis, and changes in subchondral bone. For each tissue, we will focus on the molecular receptors, cytokines, peptidases, related cell, and signal pathways. Agents that specifically block mechanisms involved in synovial inflammation, degeneration of articular cartilage, and subchondral bone remodeling can potentially be exploited to produce targeted therapy for OA. Such new comprehensive agents will benefit affected patients and bring exciting new hope for the treatment of OA.

No association of the single nucleotide polymorphism rs8044769 in the fat mass and obesity-associated gene with knee osteoarthritis risk and body mass index: A population-based study in China

OBJECTIVES

Previous genome-wide association studies (GWAS) have reported significant association of the single nucleotide polymorphism (SNP) rs8044769 in the fat mass and obesity-associated gene (FTO) with osteoarthritis (OA) risk in European populations. However, these findings have not been confirmed in Chinese populations.

METHODS

We systematically genotyped rs8044769 and evaluated the association between the genetic variants and OA risk in a case-controlled study including 196 OA cases and 442 controls in a northern Chinese population. Genotyping was performed using the Sequenom MassARRAY iPLEX platform.

RESULTS

We found that the variant T allele of rs8044769 showed no significant association of OA risk (p = 0.791), or association with body mass index (BMI) (pmeta = 0.786) in an additive genetic model. However, we detected a significant interaction between rs8044769 genotypes and BMI on OA risk (p = 0.037), as well as a borderline interaction between rs8044769 genotypes and age on OA risk (p = 0.062).

CONCLUSIONS

Our findings indicate that rs8044769 in the FTO gene may not modify individual susceptibility to OA or increased BMI in the Chinese population. Further studies are warranted to validate and extend our findings.Cite this article: Prof L. Jiang. No association of the single nucleotide polymorphism rs8044769 in the fat mass and obesity-associated gene with knee osteoarthritis risk and body mass index: A population-based study in China. Bone Joint Res 2016;5:169-174. DOI: 10.1302/2046-3758.55.2000589.

Influences on the decision to use an osteoarthritis diagnosis in primary care: a cohort study with linked survey and electronic health record data

OBJECTIVE

Clinicians may record patients presenting with osteoarthritis (OA) symptoms with joint pain rather than an OA diagnosis. This may have implications for OA research studies and patient care. The objective was to assess whether older adults recorded with joint pain are similar to those with a recorded OA diagnosis.

METHOD

A study of adults aged ≥50 years in eight United Kingdom general practices, with electronic health records linked to survey data. Patients with a recorded regional OA diagnosis were compared to those with a recorded joint pain symptom on socio-demographics, risk factors, body region, pain severity, prescribed analgesia, and potential differential diagnoses. A sub-group was compared on radiographic knee OA.

RESULTS

Thirteen thousand eight hundred and thirty-one survey responders consented to record review. One thousand four hundred and twenty-seven (10%) received an OA (n = 616) or joint pain (n = 811) code with wide practice variation. Receiving an OA diagnosis was associated with age (75+ compared to 50-64 OR 3.25; 95% Credible intervals (CrI) 2.36, 4.53), obesity (1.72; 1.22, 2.33), and pain interference (1.45; 1.09, 1.92). Analgesia management was similar. Radiographic OA was common in both groups. A quarter of those with a joint pain record received an OA diagnosis in the following 6 years.

CONCLUSION

Recording OA diagnoses are less common than recording a joint pain symptom and associated with risk factors and severity. OA studies in primary care need to consider joint pain symptoms to understand the burden and quality of care across the spectrum of OA. Patients recorded with joint pain may represent early cases of OA with need for early intervention.