Risk factors for incident radiographic knee osteoarthritis in the elderly: the Framingham Study

Systematic literature review to inform the EULAR recommendations for the use of imaging in crystal-induced arthropathies in clinical practice

OBJECTIVE

To summarise current data regarding the use of imaging in crystal-induced arthropathies (CiAs) informing a European Alliance of Associations for Rheumatology task force.

METHODS

We performed four systematic searches in Embase, Medline and Central on imaging for diagnosis, monitoring, prediction of disease severity/treatment response, guiding procedures and patient education in gout, calcium pyrophosphate dihydrate deposition (CPPD) and basic calcium phosphate deposition (BCPD). Records were screened, manuscripts reviewed and data of the included studies extracted. The risk of bias was assessed by validated instruments.

RESULTS

For gout, 88 studies were included. Diagnostic studies reported good to excellent sensitivity and specificity of dual-energy CT (DECT) and ultrasound (US), high specificity and lower sensitivity for conventional radiographs (CR) and CT. Longitudinal studies demonstrated sensitivity to change with regard to crystal deposition by US and DECT and inflammation by US and structural progression by CR and CT. For CPPD, 50 studies were included. Diagnostic studies on CR and US showed high specificity and variable sensitivity. There was a single study on monitoring, while nine assessed the prediction in CPPD. For BCPD, 56 studies were included. There were two diagnostic studies, while monitoring by CR and US was assessed in 43 studies, showing a reduction in crystal deposition. A total of 12 studies with inconsistent results assessed the prediction of treatment response. The search on patient education retrieved two studies, suggesting a potential role of DECT.

CONCLUSION

This SLR confirmed a relevant and increasing role of imaging in the field of CiAs.

Association of Weight Loss and Weight Gain With Structural Defects and Pain in Hand Osteoarthritis: Data From the Osteoarthritis Initiative

OBJECTIVE

Our aim was to define the association of weight change (weight loss or weight gain) with the incidence and progression of hand osteoarthritis (OA), assessed either by radiography or by pain, using data from the Osteoarthritis Initiative.

METHODS

Among the 4,796 participants, we selected 4,598 participants, excluding those with cancer or rheumatoid arthritis or a body mass index under 18.5 kg/m2. We investigated the association of weight change with incidence and progression of radiographic hand OA and the development and resolution of hand pain. Using multivariable logistic regression, we investigated the association of weight change from baseline to the 4-year follow-up with the incidence and progression of radiographic hand OA at the 4-year follow-up. Additionally, multivariable repeated-measure mixed-effects logistic regression analyzed the association of weight change with the development and resolution of hand pain across 2-year, 4-year, 6-year, and 8-year follow-ups.

RESULTS

No statistically significant associations were observed between weight change and the investigated outcomes. Specifically, for each 5% weight loss, the odds ratios for the incidence and progression of radiographic hand OA were 0.90 (95% confidence interval [95% CI] 0.67-1.23) and 0.92 (95% CI 0.84-1.00), respectively. Similarly, for each 5% weight loss, the odds ratios for the development and resolution of hand pain at the 8-year follow-up were 1.00 (95% CI 0.92-1.09) and 1.07 (95% CI 0.91-1.25), respectively.

CONCLUSION

Our study found no evidence of an association between weight change and the odds of incidence or progression of radiographic hand OA over 4 years, nor the development or resolution of hand pain over 8 years.

The challenge of ecological validity in temporomandibular disorders research

OBJECTIVE

To review the ecological validity of outcomes from current research involving temporomandibular disorders (TMDs), with an emphasis on chronic myofascial pain and the precocious development of degenerative disease of the temporomandibular joint (TMJ).

MATERIALS AND METHODS

Current approaches used to study TMDs in terms of neuromechanics, masticatory muscle behaviours, and the dynamics of the autonomic nervous system (ANS) were assessed for ecological validity in this review. In particular, the available literature was scrutinized regarding the effects of sampling, environmental and psychophysiological constraints and averaging data across biological rhythms.

RESULTS

Validated computer-assisted numerical modelling of the neuromechanics used biological objective functions to accurately predict muscle activation patterns for jaw-loading tasks that were individual-specific. With respect to masticatory muscle behaviour, current findings refute the premise that sustained bruxing and clenching at high jaw-loading magnitudes were associated with painful TMDs such as myofascial pain. Concerning the role of the ANS in TMDs, there remains the need for personalized assessments based on biorhythms, and where the detection of dysregulated physiologic oscillators may inform interventions to relieve pain and restore normal function.

CONCLUSIONS

Future human research which focuses on TMD myofascial pain or the precocious development and progression of TMJ degenerative joint disease requires experimental designs with ecological validity that capture objectively measured data which meaningfully reflect circadian and ultradian states.

Body mass index and meniscal tears: Evidence from meta-analysis of observational studies and Mendelian randomization

Obesity is a potential risk factor for meniscal tear (MT). We utilized meta-analysis of observational studies and Mendelian randomization (MR) analyses to elucidate the association between body mass index (BMI) and MT. In meta-analysis, a search was performed on June 27, 2022, using PubMed and Embase databases. Odds ratios and 95% confidence intervals were extracted from included studies. In MR analyses, the research utilized summary-level data on BMI and MT obtained from Genetic Investigation of Anthropometric Traits and the FinnGen Consortium, respectively. In meta-analysis, four studies comprising 826,383 participants were included. The pooled odds ratio of MT in the high BMI group was 1.32 (95% confidence interval, 0.83-2.09), compared with the nonhigh BMI group. The pooled odds ratio in the under 30 group was 1.76 (95% confidence interval, 0.61-5.03). In MR analyses, one standard deviation increase in genetically predicted BMI was associated with meniscus derangement as a chronic subtype of MT (odds ratio, 1.36; 95% confidential interval, 1.17-1.59). We found that a high BMI was not associated with an increased likelihood of MT based on meta-analysis of observational studies; however, by complementing MR analyses, we elucidated the causality of BMI increase on meniscus derangement as a chronic subtype of MT.

Metabolic syndrome is not associated with erosive hand osteoarthritis: a cross-sectional study using data from the PROCOAC cohort

To delineate the phenotype of erosive hand osteoarthritis (EHOA) in a Spanish population and assess its correlation with metabolic syndrome. We conducted a cross-sectional study using baseline data from the Prospective Cohort of Osteoarthritis from A Coruña (PROCOAC). Demographic and clinical variables, obtained through questionnaires, clinical examinations, and patient analytics, were compared among individuals with hand OA, with and without EHOA. We performed appropriate univariate and multivariate stepwise regression analyses using SPSS v28. Among 1039 subjects diagnosed with hand OA, 303 exhibited EHOA. Multivariate logistic regression analysis revealed associations with inflamed joints, nodular hand OA, and total AUSCAN. Furthermore, the association with a lower prevalence of knee OA remained significant. The influence of metabolic syndrome (MetS) on EHOA patients was analyzed by including MetS as a covariate in the model. It was observed that MetS does not significantly impact the presence of EHOA, maintaining the effect size of other factors. In conclusion, in the PROCOAC cohort, EHOA is associated with nodular hand OA, inflammatory hand OA, and a higher total AUSCAN. However, EHOA is linked to a lower prevalence of knee OA. Importantly, in our cohort, no relationship was found between EHOA and MetS.

Association of smoking with cartilage loss of knee osteoarthritis: data from two longitudinal cohorts

BACKGROUND

Previous studies have been inconsistent concerning the association between smoking and risk of osteoarthritis (OA). This study aimed to explore the associations of smoking status and change in cartilage volume of OA in two longitudinal cohorts.

METHODS

Subjects from the Osteoarthritis Initiative cohort (OAI, n = 593) and the Tasmanian Older Adult Cohort (TASOAC, n = 394) were included in this study. For both cohorts, participants were classified into three groups based on their smoking status, namely 'never', 'former', and 'current' smokers. The outcome measures were the annual rate of change of tibiofemoral cartilage volume over 2 years in OAI and of tibial cartilage volume over 2.6 years in TASOAC. Potential confounders were balanced using the inverse probability of treatment weighting (IPTW) method.

RESULTS

Overall, 42.3% and 37.4% of participants were former smokers, and 5.7% and 9.3% were current smokers in the OAI and TASOAC cohorts, respectively. Compared to never smokers, neither former nor current smoking was associated with risk of the annual rate of change of tibiofemoral cartilage volume in OAI (former smoker: β=-0.068%/year, 95% confidence interval [CI] -0.824 to 0.688, p = 0.860; current smoker: β=-0.222%/year, 95% CI -0.565 to 0.120, p = 0.204) and tibial cartilage volume in TASOAC (former smoker: β = 0.001%/year, 95% CI -0.986 to 0.989, p = 0.998; current smoker: β=-0.839%/year, 95% CI -2.520 to 0.844, p = 0.329).

CONCLUSIONS

Our findings from two independent cohorts consistently showed that smoking was not associated with knee cartilage loss in older adults.

Increased complications rates and inferior patient reported outcomes following total knee arthroplasty due to post-traumatic osteoarthritis with previous fracture treatment: a systematic review

PURPOSE

This study aims to present the existing literature relating to patient-reported outcome measures (PROMs) and complications in patients undergoing total knee arthroplasty (TKA) due to posttraumatic osteoarthritis (PTOA) with prior fracture treatment around the knee compared with patients who underwent TKA because of primary osteoarthritis (OA).

METHODS

A systematic review was undertaken and synthesised in accordance with the PRISMA guidelines by searching existing literature in the following databases: PubMed, Scopus, Cochrane Library and EMBASE. A search string according to the PECO was used. After analysing 2781 studies, 18 studies (5729 PTOA patients/149,843 OA patients) were included for a final review. An analysis revealed that 12 (67%) were retrospective cohort studies, four (22%) were register studies and the remaining two (11%) were prospective cohort studies. The mean Critical Appraisal Skills Programme (CASP) score was 23.6 out of 28, signifying studies of moderate quality.

RESULTS

The most frequently reported outcome measure were postoperative complications, reported in all eighteen studies. Intraoperative complications were reported in ten (4165 PTOA/124.511 OA) and patient-reported outcome measures (PROMs) in six studies (210 PTOA/2768 OA). A total of nine different PROMs were evaluated. As far as PROMs were concerned, the scores were inferior for PTOA but did not differ statistically from OA, except for one study, which favoured the OA group. Across all studies, postoperative complications were higher in the PTOA group, reporting infections as the most common complication. Furthermore, a higher revision rate was reported in the PTOA group.

CONCLUSION

PROM analysis suggests that both patient groups benefit from a TKA in terms of functional outcome and pain relief, however, patient-reported outcomes could be inferior for PTOA patients. There is consistent evidence for increased complication rates following PTOA TKA. Patients undergoing TKA due to PTOA after fracture treatment should be informed about the risk for inferior results and refrain from comparing their knee function to patients with TKA after OA. Surgeons should be aware of the challenges that PTOA TKA poses.

LEVEL OF EVIDENCE

Level III.

Shear wave elastography and T2* mapping in the detection of early-stage trochlear cartilage damage

BACKGROUND

The presence of degenerative changes in joint cartilage is one of the major features in osteoarthritis.

PURPOSE

To investigate the contribution of shear wave elastography and T2* mapping to the early diagnosis of femoral trochlear cartilage damage.

MATERIAL AND METHODS

A total of 30 individuals whose trochlear cartilage structure was evaluated as normal in conventional magnetic resonance imaging (MRI) sequences (control group) were prospectively compared with 30 patients who had early-stage cartilage damage findings on conventional MRI (study group), by performing B-mode ultrasonography, shear wave elastography, and T2* mapping. Cartilage thickness, shear wave, and T2* mapping measurements were recorded.

RESULTS

After evaluating B-mode ultrasound and conventional MRI sequences, cartilage thickness was found to be significantly higher in the study group on both B-mode ultrasound and MRI. Shear wave velocity values of the study group (medial condyle [MC] 4.65 ± 1.11 m/sn, intercondylar [IC] 4.74 ± 1.20 m/sn, and lateral condyle [LC] 5.42 ± 1.48 m/sn) were observed to be significantly lower than the control group (MC 5.60 ± 0.77 m/sn, IC 5.85 ± 0.96 m/sn, and LC 5.63 ± 1.05 m/sn) (P < 0.05). T2* mapping values were significantly higher in the study group (MC 32.38 ± 4.04 ms, IC 35.78 ± 4.85 ms, and LC 34.04 ± 3.40 ms) than that of the control group (MC 28.07 ± 3.29 ms, IC 30.63 ± 3.45 ms, and LC 29.02 ± 3.24 ms).

CONCLUSION

Shear wave elastography and T2* mapping are reliable methods for evaluating early-stage trochlear cartilage damage.

Obesity, Metabolic Syndrome, and Osteoarthritis-An Updated Review

PURPOSE OF REVIEW

Metabolic syndrome (MetS), also called the 'deadly quartet' comprising obesity, diabetes, dyslipidemia, and hypertension, has been ascertained to have a causal role in the pathogenesis of osteoarthritis (OA). This review is aimed at discussing the current knowledge on the contribution of metabolic syndrome and its various components to OA pathogenesis and progression.

RECENT FINDINGS

Lately, an increased association identified between the various components of metabolic syndrome (obesity, diabetes, dyslipidemia, and hypertension) with OA has led to the identification of the 'metabolic phenotype' of OA. These metabolic perturbations alongside low-grade systemic inflammation have been identified to inflict detrimental effects upon multiple tissues of the joint including cartilage, bone, and synovium leading to complete joint failure in OA. Recent epidemiological and clinical findings affirm that adipokines significantly contribute to inflammation, tissue degradation, and OA pathogenesis mediated through multiple signaling pathways. OA is no longer perceived as just a 'wear and tear' disease and the involvement of the metabolic components in OA pathogenesis adds up to the complexity of the disease. Given the global surge in obesity and its allied metabolic perturbations, this review aims to throw light on the current knowledge on the pathophysiology of MetS-associated OA and the need to address MetS in the context of metabolic OA management. Better regulation of the constituent factors of MetS could be profitable in preventing MetS-associated OA. The identification of key roles for several metabolic regulators in OA pathogenesis has also opened up newer avenues in the recognition and development of novel therapeutic agents.

Association of physical activity with loss of knee joint space width over two years: a compositional data analysis in the Osteoarthritis Initiative

OBJECTIVE

There is continued debate as to how engaging in physical activity (PA), including moderate-to-vigorous PA (MVPA), light PA (LPA), and sedentary time (SED), affects one's risk for knee osteoarthritis (OA). Traditional regression methods do not account for the codependence of these categories of PA, whereby when one category increases, the others must decrease. Thus, we used compositional data analysis (CoDA) to examine time spent in each category of PA, or PA composition, and its association with loss of knee joint space width (JSW), a common indicator of knee OA progression.

METHODS

We performed a secondary analysis of data from a subset of participants in the Osteoarthritis Initiative. These participants had minute-by-minute activity data collected over 7 days at baseline; we then categorized each minute as MVPA, LPA, or SED. Our exposure, PA composition, represented min/day spent in each category. Our outcome, medial JSW loss, was the difference in medial tibiofemoral JSW from baseline to 2 years later. We employed CoDA, using an isometric log-ratio transformation, to examine the association of PA composition with medial JSW loss over 2 years, adjusting for potential confounders.

RESULTS

We included 969 participants (age: 64.5 years, 56% female, body mass index [BMI]: 28.8 kg/m2). Mean PA composition was: MVPA 9.1 min/day, LPA 278 min/day, SED 690 min/day. Per adjusted regression models, higher MVPA was not associated with greater medial JSW loss (β = -0.0005, P = 0.97), nor was LPA (β = 0.06, P = 0.27) or SED (β = -0.06, P = 0.21).

CONCLUSION

Using CoDA, PA composition was not associated with medial JSW loss over 2 years.

A systematic review of the sex differences in risk factors for knee osteoarthritis

OBJECTIVES

Previous systematic reviews focused on the evidence of common risk factors for knee OA (KOA); however, the effect and strength of association between risk factors and KOA might be different between the two sexes. The aim of the present systematic review was to determine the current evidence on sex differences in the association between risk factors and KOA and their prevalence.

METHODS

We searched the following electronic bibliographic databases: MEDLINE (PubMed), EMBASE and Web of Science. A methodological quality assessment was conducted independently by two researchers according to an adapted version of the standardized set of criteria known as the Newcastle-Ottawa Quality Assessment Scale (NOS). The NOS, a star system, was converted to three categories of quality.

RESULTS

In total, 27 studies reported sex-specific risk estimates on several risk factors for KOA. Out of the 22 longitudinal cohort studies (except one nested case-control), 12 were of good quality and 10 were of fair quality. The five cross-sectional studies consisted of one of good, three of fair and one of poor quality. There was an indication of sex differences in risk factors leading to higher risk of KOA: high BMI, alcohol consumption, atherosclerosis and high vitamin E levels in women, and high physical activity, soft drink consumption and abdominal obesity in men. Knee injury, high blood pressure and low step rate seem to affect both women and men.

CONCLUSION

More good quality studies are needed to assess sex differences in risk factors for KOA, especially for symptomatic/clinical OA.

Culture-expanded mesenchymal stromal cell therapy: does it work in knee osteoarthritis? A pathway to clinical success

Osteoarthritis (OA) is a degenerative multifactorial disease with concomitant structural, inflammatory, and metabolic changes that fluctuate in a temporal and patient-specific manner. This complexity has contributed to refractory responses to various treatments. MSCs have shown promise as multimodal therapeutics in mitigating OA symptoms and disease progression. Here, we evaluated 15 randomized controlled clinical trials (RCTs) and 11 nonrandomized RCTs using culture-expanded MSCs in the treatment of knee OA, and we found net positive effects of MSCs on mitigating pain and symptoms (improving function in 12/15 RCTs relative to baseline and in 11/15 RCTs relative to control groups at study endpoints) and on cartilage protection and/or repair (18/21 clinical studies). We examined MSC dose, tissue of origin, and autologous vs. allogeneic origins as well as patient clinical phenotype, endotype, age, sex and level of OA severity as key parameters in parsing MSC clinical effectiveness. The relatively small sample size of 610 patients limited the drawing of definitive conclusions. Nonetheless, we noted trends toward moderate to higher doses of MSCs in select OA patient clinical phenotypes mitigating pain and leading to structural improvements or cartilage preservation. Evidence from preclinical studies is supportive of MSC anti-inflammatory and immunomodulatory effects, but additional investigations on immunomodulatory, chondroprotective and other clinical mechanisms of action are needed. We hypothesize that MSC basal immunomodulatory "fitness" correlates with OA treatment efficacy, but this hypothesis needs to be validated in future studies. We conclude with a roadmap articulating the need to match an OA patient subset defined by molecular endotype and clinical phenotype with basally immunomodulatory "fit" or engineered-to-be-fit-for-OA MSCs in well-designed, data-intensive clinical trials to advance the field.

Researchers in rheumatology should avoid categorization of continuous predictor variables

BACKGROUND

Rheumatology researchers often categorize continuous predictor variables. We aimed to show how this practice may alter results from observational studies in rheumatology.

METHODS

We conducted and compared the results of two analyses of the association between our predictor variable (percentage change in body mass index [BMI] from baseline to four years) and two outcome variable domains of structure and pain in knee and hip osteoarthritis. These two outcome variable domains covered 26 different outcomes for knee and hip combined. In the first analysis (categorical analysis), percentage change in BMI was categorized as ≥ 5% decrease in BMI, < 5% change in BMI, and ≥ 5% increase in BMI, while in the second analysis (continuous analysis), it was left as a continuous variable. In both analyses (categorical and continuous), we used generalized estimating equations with a logistic link function to investigate the association between the percentage change in BMI and the outcomes.

RESULTS

For eight of the 26 investigated outcomes (31%), the results from the categorical analyses were different from the results from the continuous analyses. These differences were of three types: 1) for six of these eight outcomes, while the continuous analyses revealed associations in both directions (i.e., a decrease in BMI had one effect, while an increase in BMI had the opposite effect), the categorical analyses showed associations only in one direction of BMI change, not both; 2) for another one of these eight outcomes, the categorical analyses suggested an association with change in BMI, while this association was not shown in the continuous analyses (this is potentially a false positive association); 3) for the last of the eight outcomes, the continuous analyses suggested an association of change in BMI, while this association was not shown in the categorical analyses (this is potentially a false negative association).

CONCLUSIONS

Categorization of continuous predictor variables alters the results of analyses and could lead to different conclusions; therefore, researchers in rheumatology should avoid it.

Osteoarthritis and Diabetes: Where Are We and Where Should We Go?

Diabetes mellitus (DM) and osteoarthritis (OA) are chronic noncommunicable diseases that affect millions of people worldwide. OA and DM are prevalent worldwide and associated with chronic pain and disability. Evidence suggests that DM and OA coexist within the same population. The coexistence of DM in patients with OA has been linked to the development and progression of the disease. Furthermore, DM is associated with a greater degree of osteoarthritic pain. Numerous risk factors are common to both DM and OA. Age, sex, race, and metabolic diseases (e.g., obesity, hypertension, and dyslipidemia) have been identified as risk factors. These risk factors (demographics and metabolic disorder) are associated with DM or OA. Other possible factors may include sleep disorders and depression. Medications for metabolic syndromes might be related to the incidence and progression of OA, with conflicting results. Given the growing body of evidence indicating a relationship between DM and OA, it is vital to analyze, interpret, and integrate these findings. Therefore, the purpose of this review was to evaluate the evidence on the prevalence, relationship, pain, and risk factors of both DM and OA. The research was limited to knee, hip, and hand OA.

Incidence and severity of radiological lateral osteoarthritis 15 years following medial unicompartmental knee arthroplasty

To assess the incidence of radiological lateral osteoarthritis (OA) at 15 years after medial unicompartmental knee arthroplasty (UKA) and assess the relationship of lateral OA with symptoms and patient characteristics. Cemented Phase 3 medial Oxford UKA implanted by two surgeons since 1998 for the recommended indications were prospectively followed. A 15-year cumulative revision rate for lateral OA of 5% for this series was previously reported. A total of 163 unrevised knees with 15-year (SD 1) anterior-posterior knee radiographs were studied. Lateral joint space width (JSW_L) was measured and severity of lateral OA was classified as: nil/mild, moderate, and severe. Preoperative and 15-year Oxford Knee Scores (OKS) and American Knee Society Scores were determined. The effect of age, sex, BMI, and intraoperative findings was analyzed. Statistical analysis included one-way analysis of variance and Kruskal-Wallis H test, with significance set at 5%. The mean age was 80.6 years (SD 8.3), with 84 females and 79 males. The mean JSW_L was 5.6 mm (SD 1.4), and was not significantly related to age, sex, or intraoperative findings. Those with BMI > 40 kg/m² had a smaller JSW_L than those with a 'normal' BMI (p = 0.039). The incidence of severe and moderate lateral OA were both 4.9%. Overall, 2/142 (1.4%) of those with nil/mild lateral OA, 1/8 (13%) with moderate, and 2/8 (25%) with severe subsequently had a revision. Those with severe (mean OKS 35.6 (SD 9.3)) and moderate OA (mean OKS 35.8 (SD 10.5)) tended to have worse outcome scores than those with nil/mild (mean OKS 39.5 (SD 9.2)) but the difference was only significant for OKS-Function (p = 0.044). This study showed that the rate of having severe or moderate radiological lateral OA at 15 years after medial UKA was low (both 4.9%). Although patients with severe or moderate lateral OA had a lower OKS than those with nil/mild OA, their mean scores (OKS 36) would be classified as good.

Which are the most frequently involved peripheral joints in calcium pyrophosphate crystal deposition at imaging? A systematic literature review and meta-analysis by the OMERACT ultrasound – CPPD subgroup

Objectives

To identify the prevalence of calcium pyrophosphate crystal deposition (CPPD) using ultrasound and conventional radiology at peripheral joints in patients with suspected or definite CPPD.

Methods

A systematic literature search was performed in PubMed and Embase using pre-defined search strategies from inception to April 2021 to identify studies that evaluated conventional radiology and ultrasound in detecting CPPD at peripheral joints, including definite or suspected CPPD [Research question 1 (RQ1) and Research Question 2 (RQ2), respectively]. For the meta-analysis, the first, second, and third sub-analysis included studies with the knee, and knee or wrist as the index joint for CPPD (without restrictions on the reference standard) and synovial fluid analysis or histology as a reference standard (without restrictions on the index joint), respectively.

Results

One-thousand eight hundred and twenty-seven manuscripts were identified, of which 94 articles were finally included. Twenty-two and seventy-two papers were included in RQ1 and RQ2, respectively. The knee had the highest prevalence for RQ1 and RQ2 by both conventional radiology and ultrasound, followed by the wrist with the highest prevalence for RQ1. The hand had the lowest CPPD prevalence. The third sub-analysis showed a higher CPPD prevalence on ultrasound than conventional radiology at the knee (only data available).

Conclusion

Among all peripheral joints, the knees and wrists could be regarded as the target joints for CPPD detection by imaging. Furthermore, ultrasound seems to detect a higher number of calcium pyrophosphate deposits than conventional radiology, even when using a more restrictive reference standard.

Sex-specific effects of calving season on joint health and biomarkers in Montana ranchers

BACKGROUND

Agricultural workers have a higher incidence of osteoarthritis (OA), but the etiology behind this phenomenon is unclear. Calving season, which occurs in mid- to late-winter for ranchers, includes physical conditions that may elevate OA risk. Our primary aim was to determine whether OA biomarkers are elevated at the peak of calving season compared to pre-season, and to compare these data with joint health survey information from the subjects. Our secondary aim was to detect biomarker differences between male and female ranchers.

METHODS

During collection periods before and during calving season, male (n = 28) and female (n = 10) ranchers completed joint health surveys and provided samples of blood, urine, and saliva for biomarker analysis. Statistical analyses examined associations between mean biomarker levels and survey predictors. Ensemble cluster analysis identified groups having unique biomarker profiles.

RESULTS

The number of calvings performed by each rancher positively correlated with plasma IL-6, serum hyaluronic acid (HA) and urinary CTX-I. Thiobarbituric acid reactive substances (TBARS), a marker of oxidative stress, was significantly higher during calving season than pre-season and was also correlated with ranchers having more months per year of joint pain. We found evidence of sexual dimorphism in the biomarkers among the ranchers, with leptin being elevated and matrix metalloproteinase-3 diminished in female ranchers. The opposite was detected in males. WOMAC score was positively associated with multiple biomarkers: IL-6, IL-2, HA, leptin, C2C, asymmetric dimethylarginine, and CTX-I. These biomarkers represent enzymatic degradation, inflammation, products of joint destruction, and OA severity.

CONCLUSIONS

The positive association between number of calvings performed by each rancher (workload) and both inflammatory and joint tissue catabolism biomarkers establishes that calving season is a risk factor for OA in Montana ranchers. Consistent with the literature, we found important sex differences in OA biomarkers, with female ranchers showing elevated leptin, whereas males showed elevated MMP-3.

Cartilage calcification in osteoarthritis: mechanisms and clinical relevance

Pathological calcification of cartilage is a hallmark of osteoarthritis (OA). Calcification can be observed both at the cartilage surface and in its deeper layers. The formation of calcium-containing crystals, typically basic calcium phosphate (BCP) and calcium pyrophosphate dihydrate (CPP) crystals, is an active, highly regulated and complex biological process that is initiated by chondrocytes and modified by genetic factors, dysregulated mitophagy or apoptosis, inflammation and the activation of specific cellular-signalling pathways. The links between OA and BCP deposition are stronger than those observed between OA and CPP deposition. Here, we review the molecular processes involved in cartilage calcification in OA and summarize the effects of calcium crystals on chondrocytes, synovial fibroblasts, macrophages and bone cells. Finally, we highlight therapeutic pathways leading to decreased joint calcification and potential new drugs that could treat not only OA but also other diseases associated with pathological calcification.

Factors affecting pain and physical functions in patients with knee osteoarthritis: An observational study

Knee osteoarthritis (KOA) is more common as people age and have a higher body mass index (BMI). We must know the role of various factors in pain and physical functions in patients with KOA. Therefore, the present study sought to examine the factors associated with pain and physical functions in individuals with KOA. This cross-sectional observational study included patients with KOA (n = 125; 57 men, 68 women; mean age 52.9 years). Using the visual analogue scale and a reduced version of the Western Ontario McMaster Universities Osteoarthritis Index, pain severity and physical functions were assessed. Demographic factors such as age, BMI, sex, and Kellgren-Lawrence (K/L) radiographic grade of KOA were analyzed. Age (R = 0.263, P < .001), BMI (R = 0.379, P < .001), and K/L grade (R = 0.844, P < .001) were significantly associated with knee pain. Similarly, age (R = 0.310, P < .001), BMI (R = 0.374, P < .001), and K/L grade (R = 0.862, P < .001) were associated with physical functions. No significant association of sex with pain (R = 0.071, P = .440) and physical functions (R = 0.055, P = .545) was observed. Age, BMI, and K/L grade explained 71% and 74% of knee pain and physical functions, respectively. Age, BMI, and radiographic (K/L) grades were associated with pain and physical functions in patients with KOA. K/L grade was the most significant predictor of pain and physical functions in KOA.

Acute effects of low load resistance training with blood flow restriction on serum growth hormone, insulin-like growth factor-1, and testosterone in patients with mild to moderate unilateral knee osteoarthritis

Objective

To investigate the acute effects of blood flow restriction (BFR) with single-leg low load resistance exercise and high load resistance exercise on serum insulin-like growth factor-1 (IGF-1), growth hormone (GH), and testosterone in patients with unilateral knee osteoarthritis (OA).

Methods

This study recruited 18 postmenopausal female patients with mild to moderate unilateral knee OA, which was then followed by randomly conducting three resistance exercise protocols by drawing lots: 1. A 30% 1-repetition maximum (1-RM) resistance exercise with BFR of 70% arterial occlusive pressure (AOP) (BFR group); 2. A 70% 1-RM resistance exercise without BFR (RES group); 3. A 30% 1-RM resistance exercise without BFR (CON group). Blood lactate (BLA) and muscle growth related hormone levels were tested at 4-time points: before exercise, immediately after exercise, 15 min after exercise, and 30 min after exercise.

Results

There was no statistical difference between the indexes in each group before exercise, but the different exercise had different effects on each index and also an interactive effect (P < 0.05). The increase of rating of perceived exertion in the BFR and RES groups, which were of similar magnitude, was greater compared to the levels in the CON group (P < 0.05). Post-exercise BLA levels were lower in the CON group in comparison to the BFR and RES groups (P < 0.05). Rather than the RES group, GH levels of the BFR group were also significantly higher than the CON group (P < 0.05) at 15 min post-exercise. At post- and 15 min after exercise, the CON group recorded significantly lower IGF-1 levels compared to the BFR and RES groups (P < 0.05). At post- and 15 min after exercise, the CON group (P < 0.05) reflected the lowest testosterone levels, followed by the RES group (P < 0.05), and the highest in the BFR group (P < 0.05).

Conclusions

Myogenesis-related hormones in women with unilateral knee OA could be increased by high load resistance exercise and low load resistance exercise with BFR on unaffected limb.

FDA/Arthritis Foundation osteoarthritis drug development workshop recap: Assessment of long-term benefit

OBJECTIVE

To summarize proceedings of a workshop convened to discuss the current state of science in the disease of osteoarthritis (OA), identify the knowledge gaps, and examine the developmental and regulatory challenges in bringing these products to market.

DESIGN

Summary of the one-day workshop held virtually on June 22nd, 2021.

RESULTS

Speakers selected by the Planning Committee presented data on the current approach to assessment of OA therapies, biomarkers in OA drug development, and the assessment of disease progression and long-term benefit.

CONCLUSIONS

Demonstrated by numerous failed clinical trials, OA is a challenging disease for which to develop therapeutics. The challenge is magnified by the slow time of onset of disease and the need for clinical trials of long duration and/or large sample size to demonstrate the effect of an intervention. The OA science community, including academia, pharmaceutical companies, regulatory agencies, and patient communities, must continue to develop and test better clinical endpoints that meaningfully reflect disease modification related to long-term patient benefit.

Colchicine versus Physical Therapy in Knee Osteoarthritis

Background: The treatment of osteoarthritis remains a major challenge due to the unavailability of a disease-modifying medication and the limitations of current therapeutic perspectives, which mainly target the symptoms, not the disease itself. The purpose of our study is to compare the efficacy of colchicine treatment versus physical therapy. Methods: The study included 62 patients diagnosed with knee osteoarthritis (KOA) according to the American College of Rheumatology (ACR) criteria, hospitalized within the time frame of October 2020−March 2022 in the Department of Rehabilitation Medicine and Physical Therapy of the Emergency Clinical County Hospital of Craiova. The participants were randomly divided into two groups. The observation period was 16 weeks long. The first group (31 patients) received colchicine at a dosage of 1 mg/day together with analgesics (acetaminophen < 2 g/day), while the second group (31 patients) received analgesics (acetaminophen < 2 g/day) together with a 16-week plan of physiotherapy. Results: Group II, in which patients underwent physical therapy, demonstrated a statistically significant decrease in both left (p < 0.001) and right (p = 0.012) knee VAS and WOMAC (p = 0.038) scores at 16 weeks, compared to the group treated with colchicine. Regarding the MSUS examination at 16 weeks, there were no significant changes in the structural abnormalities and no improvement in cartilage aspect or thickness. Higher BMI was associated with higher WOMAC score (p = 0.012), but not with higher VAS score (p = 0.062). Cholesterol and triglyceride levels were associated with high WOMAC (p < 0.001; p = 0.021) and high VAS (p = 0.023; p < 0.001) scores. Conclusions: Our study monitored VAS and WOMAC scores in two groups of patients with KOA, showing that physical therapy is more effective than colchicine in reducing symptoms. We found no statistically significant difference in musculoskeletal ultrasound (MSUS) feature improvement during the 16-week study.

Strain sonoelastography in asymptomatic individuals and individuals with knee osteoarthritis: an evaluation of quadriceps and patellar tendon

An advanced ultrasound imaging technique, sonoelastography (SE) is used to evaluate tissue elasticity. To determine SE potential to detect pathological-related changes, and characteristics related to tendon pathology we aimed to (1) compare quadriceps and patellar tendon findings in individuals with knee osteoarthritis (KOA) and asymptomatic older adults (AC), and (2) explore associations between SE, participant characteristics (age, BMI, and leg circumference) and KOA status. 84 participants (47; KOA and 37; asymptomatic older adults) underwent SE examination of quadriceps (distal) and patellar (distal, proximal) tendon in a supine position with the knee bent at 30°. Colour score (CS) and Elasticity Ratio (ER) analysis were performed by a blinded experienced operator using Esaote Mylab 70 XVG Ultrasound equipment. Significantly reduced elasticity in the distal quadriceps (median (IQR) 2(2), 3(1), p = 0.033 for KOA and AC, respectively) and proximal patellar (3(1), 3(0), p = 0.001) tendons and more elastic distal patellar (1.50 (0.55), 1.87 (0.72), p = 0.034) tendons were observed in the KOA group. Significant associations) were identified between SE and participant BMI (Rs = − 0.249–0.750, p < 0.05) and leg circumference (Rs = − 0.260–0.903, p < 0.05). Age, BMI and KOA status, were independent explanatory variables of SE CS findings at the distal quadriceps tendon patellar tendon, proximal patellar tendon and distal patellar tendon, explaining 66%, 81% and 64% of variance, respectively. Age, BMI and KOA status were independent explanatory variables of SE ER findings at the distal patellar tendon explaining 19% of variance. Potentially clinically relevant altered tendon stiffness were observed between individuals with KOA and asymptomatic controls. Key KOA risk factors and participant characteristics explained variance in tendon stiffness. Findings provide context for future studies to investigate the potential for targeted SE detected early clinical management based on associated participant characteristics.

Association of Decrease in Body Mass Index With Reduced Incidence and Progression of the Structural Defects of Knee Osteoarthritis: A Prospective Multi-Cohort Study

OBJECTIVE

To define the association between change in body mass index (BMI) and the incidence and progression of the structural defects of knee osteoarthritis as assessed by radiography.

METHODS

Radiographic analyses of knees at baseline and at 4-5 years of follow-up were obtained from the following 3 independent cohort studies: the Osteoarthritis Initiative (OAI) study, the Multicenter Osteoarthritis Study (MOST), and the Cohort Hip and Cohort Knee (CHECK) study. Logistic regression analyses using generalized estimating equations, with clustering of both knees within individuals, were used to investigate the association between change in BMI from baseline to 4-5 years of follow-up and the incidence and progression of knee osteoarthritis.

RESULTS

A total of 9,683 knees (from 5,774 participants) in an "incidence cohort" and 6,075 knees (from 3,988 participants) in a "progression cohort" were investigated. Change in BMI was positively associated with both the incidence and progression of the structural defects of knee osteoarthritis. The adjusted odds ratio (OR) for osteoarthritis incidence was 1.05 (95% confidence interval [95% CI] 1.02-1.09), and the adjusted OR for osteoarthritis progression was 1.05 (95% CI 1.01-1.09). Change in BMI was also positively associated with degeneration (i.e., narrowing) of the joint space and with degeneration of the femoral and tibial surfaces (as indicated by osteophytes) on the medial but not on the lateral side of the knee.

CONCLUSION

A decrease in BMI was independently associated with lower odds of incidence and progression of the structural defects of knee osteoarthritis and could be a component in preventing the onset or worsening of knee osteoarthritis.

Effect of aerobic exercise on waist circumference in adults with overweight or obesity: A systematic review and meta-analysis

Excess visceral adiposity contributes to elevated cardiometabolic risk, and waist circumference is commonly used as a surrogate measure of visceral adipose tissue. Although regular aerobic exercise is known to improve abdominal obesity, its effect on waist circumference is unclear. A systematic review and meta-analysis was performed to determine (1) the effect of aerobic exercise on waist circumference in adults with overweight or obesity; (2) the association between any change in waist circumference and change in visceral adipose tissue and/or bodyweight with aerobic exercise interventions; and (3) if reductions in waist circumference with exercise are moderated by clinical characteristics or components of aerobic exercise prescription. Twenty-five randomized controlled trials (1686 participants) were included. Regular aerobic exercise significantly reduced waist circumference by 3.2 cm (95% confidence interval [CI] -3.86, -2.51, p ≤ 0.001) versus control. Change in waist circumference was associated with change in visceral adipose tissue (β = 4.02; 95% CI 1.37, 6.66, p = 0.004), and vigorous intensity produced superior reduction (-4.2 cm, 95% CI -4.99, -3.42, p < 0.0001) in waist circumference compared with moderate intensity (-2.50 cm, 95% CI -3.22, -1.79, p = 0.058). These findings suggest regular aerobic exercise results in modest reductions in waist circumference and associated visceral adipose tissue and that higher intensity exercise may offer superior benefit to moderate intensity.

Exercise for Osteoarthritis: A Literature Review of Pathology and Mechanism

Osteoarthritis (OA) has a very high incidence worldwide and has become a very common joint disease in the elderly. Currently, the treatment methods for OA include surgery, drug therapy, and exercise therapy. In recent years, the treatment of certain diseases by exercise has received increasing research and attention. Proper exercise can improve the physiological function of various organs of the body. At present, the treatment of OA is usually symptomatic. Limited methods are available for the treatment of OA according to its pathogenesis, and effective intervention has not been developed to slow down the progress of OA from the molecular level. Only by clarifying the mechanism of exercise treatment of OA and the influence of different exercise intensities on OA patients can we choose the appropriate exercise prescription to prevent and treat OA. This review mainly expounds the mechanism that exercise alleviates the pathological changes of OA by affecting the degradation of the ECM, apoptosis, inflammatory response, autophagy, and changes of ncRNA, and summarizes the effects of different exercise types on OA patients. Finally, it is found that different exercise types, exercise intensity, exercise time and exercise frequency have different effects on OA patients. At the same time, suitable exercise prescriptions are recommended for OA patients.

Fundamentals of OA. An initiative of Osteoarthritis and Cartilage. Obesity and metabolic factors in OA

OBJECTIVE

Obesity was once considered a risk factor for knee osteoarthritis (OA) primarily for biomechanical reasons. Here we provide an additional perspective by discussing how obesity also increases OA risk by altering metabolism and inflammation.

DESIGN

This narrative review is presented in four sections: 1) metabolic syndrome and OA, 2) metabolic biomarkers of OA, 3) evidence for dysregulated chondrocyte metabolism in OA, and 4) metabolic inflammation: joint tissue mediators and mechanisms.

RESULTS

Metabolic syndrome and its components are strongly associated with OA. However, evidence for a causal relationship is context dependent, varying by joint, gender, diagnostic criteria, and demographics, with additional environmental and genetic interactions yet to be fully defined. Importantly, some aspects of the etiology of obesity-induced OA appear to be distinct between men and women, especially regarding the role of adipose tissue. Metabolomic analyses of serum and synovial fluid have identified potential diagnostic biomarkers of knee OA and prognostic biomarkers of disease progression. Connecting these biomarkers to cellular pathophysiology will require future in vivo studies of joint tissue metabolism. Such studies will help reveal when a metabolic process or a metabolite itself is a causal factor in disease progression. Current evidence points towards impaired chondrocyte metabolic homeostasis and metabolic-immune dysregulation as likely factors connecting obesity to the increased risk of OA.

CONCLUSIONS

A deeper understanding of how obesity alters metabolic and inflammatory pathways in synovial joint tissues is expected to provide new therapeutic targets and an improved definition of "metabolic" and "obesity" OA phenotypes.

Recreational Physical Activity and Risk of Incident Knee Osteoarthritis: An International Meta-Analysis of Individual Participant-Level Data

OBJECTIVE

The effect of physical activity on the risk of developing knee osteoarthritis (OA) is unclear. We undertook this study to examine the relationship between recreational physical activity and incident knee OA outcomes using comparable physical activity and OA definitions.

METHODS

Data were acquired from 6 global, community-based cohorts of participants with and those without knee OA. Eligible participants had no evidence of knee OA or rheumatoid arthritis at baseline. Participants were followed up for 5-12 years for incident outcomes including the following: 1) radiographic knee OA (Kellgren-Lawrence [K/L] grade ≥2), 2) painful radiographic knee OA (radiographic OA with knee pain), and 3) OA-related knee pain. Self-reported recreational physical activity included sports and walking/cycling activities and was quantified at baseline as metabolic equivalents of task (METs) in days per week. Risk ratios (RRs) were calculated and pooled using individual participant data meta-analysis. Secondary analysis assessed the association between physical activity, defined as time (hours per week) spent in recreational physical activity and incident knee OA outcomes.

RESULTS

Based on a total of 5,065 participants, pooled RR estimates for the association of MET days per week with painful radiographic OA (RR 1.02 [95% confidence interval (95% CI) 0.93-1.12]), radiographic OA (RR 1.00 [95% CI 0.94-1.07]), and OA-related knee pain (RR 1.00 [95% CI 0.96-1.04]) were not significant. Similarly, the analysis of hours per week spent in physical activity also showed no significant associations with all outcomes.

CONCLUSION

Our findings suggest that whole-body, physiologic energy expenditure during recreational activities and time spent in physical activity were not associated with incident knee OA outcomes.

Prevalence, Incidence, and Progression of Radiographic and Symptomatic Hand Osteoarthritis: The Osteoarthritis Initiative

OBJECTIVE

To describe prevalence, incidence, and progression of radiographic and symptomatic hand osteoarthritis (OA), and evaluate age, sex, race and risk factors differences.

METHODS

We assessed both radiographic and symptomatic hand OA at baseline and year 4 for incident disease. A modified poisson regression with a robust variance estimator was used to account for clustering of joints within fingers within persons to estimate the prevalence ratios and relative risk estimates associated with participant characteristics.

RESULTS

Of 3588 participants, the prevalence hand OA was 41.4% for radiographic hand OA and 12.4 % for symptomatic hand OA. The incidence of hand OA over 48 months was 5.6 % for radiographic hand OA, and 16.9 % for symptomatic hand OA. Over 48 months, 27.3 % participants exhibited OA progression. We found complex differences by age, sex and race with both men and women having increasing prevalent hand OA with age, but women peaking at age 55-65, for incident disease. Women have more symptomatic hand OA than men but only non-significantly higher rates for incident radiographic hand OA. Women have more distal interphalangeal joint disease while men have more metacarpal joint OA. Black men and women have less hand OA than whites but black men have more hand OA than black women at younger ages.

CONCLUSION

Hand OA is a heterogeneous disease with complex differences by age, sex and race, hand symptoms and patterns of specific joints. Further research investigating the mechanisms behind these differences whether mechanical, metabolic, hormonal, or constitutional is warranted.

Relationship of Patellofemoral Osteoarthritis to Changes in Performance-based Physical Function Over 7 Years: The Multicenter Osteoarthritis Study

OBJECTIVE

To determine the relationship of patellofemoral osteoarthritis (PFOA) to changes in performance-based function over 7 years.

METHODS

There were 2666 participants (62.2 ± 8.0 yrs, BMI 30.6 ± 5.9 kg/m2, 60% female) from the Multicenter Osteoarthritis Study with knee radiographs at baseline who completed repeated chair stands and a 20-meter walk test (20MWT) at baseline, 2.5, 5, and 7 years. Generalized linear models assessed the relation of radiographic PFOA and radiographic PFOA with frequent knee pain to longitudinal changes in performance-based function. Analyses were adjusted for age, sex, BMI, tibiofemoral OA, and injury/surgery.

RESULTS

Linear models demonstrated a significant group-by-time interaction for the repeated chair stands (P = 0.04) and the 20MWT (P < 0.0001). Those with radiographic PFOA took 1.01 seconds longer on the repeated chair stands (P = 0.02) and 1.69 seconds longer on the 20MWT (P < 0.0001) at 7 years compared with baseline. When examining the relation of radiographic PFOA with frequent knee pain to performance-based function, there was a significant group-by-time interaction for repeated chair stands (P = 0.05) and the 20MWT (P < 0.0001). Those with radiographic PFOA with frequent knee pain increased their time on the repeated chair stands by 1.12 seconds (P = 0.04) and on the 20MWT by 1.91 seconds (P < 0.0001) over 7 years.

CONCLUSION

Individuals with radiographic PFOA and those with radiographic PFOA with frequent knee pain have worsening of performance-based function over time. This knowledge may present opportunities to plan for early treatment strategies for PFOA to limit functional decline over time.

Associations of Metabolic Syndrome and Its Components with the Risk of Incident Knee Osteoarthritis Leading to Hospitalization: A 32-Year Follow-up Study

OBJECTIVES

To examine whether metabolic syndrome or its individual components predict the risk of incident knee osteoarthritis (OA) in a prospective cohort study during a 32-year follow-up period.

DESIGN

The cohort consisted of 6274 participants of the Mini-Finland Health Survey, who were free from knee OA and insulin-treated diabetes at baseline. Information on the baseline characteristics, including metabolic syndrome components, hypertension, elevated fasting glucose, elevated triglycerides, reduced high-density lipoprotein, and central obesity were collected during a health examination. We drew information on the incidence of clinical knee OA from the national Care Register for Health Care. Of the participants, 459 developed incident knee OA. In our full model, age, gender, body mass index, history of physical workload, smoking history, knee complaint, and previous injury of the knee were entered as potential confounding factors.

RESULTS

Having metabolic syndrome at baseline was not associated with an increased risk of incident knee OA. In the full model, the hazard ratio for incident knee OA for those with metabolic syndrome was 0.76 (95% confidence interval [0.56, 1.01]). The number of metabolic syndrome components or any individual component did not predict an increased risk of knee OA. Of the components, elevated plasma fasting glucose was associated with a reduced risk of incident knee OA (hazard ratio 0.71, 95% confidence interval [0.55, 0.91]).

CONCLUSIONS

Our findings do not support the hypothesis that metabolic syndrome or its components increase the risk of incident knee OA. In fact, elevated fasting glucose levels seemed to predict a reduced risk.

Trends and Patterns of Knee Osteoarthritis in China: A Longitudinal Study of 17.7 Million Adults from 2008 to 2017

Background: Knee osteoarthritis (KOA) provides many challenges on the healthcare system. However, few studies have reported the epidemiology, particularly in a large population. Our study aimed to estimate the prevalence, incidence, trends, and patterns of diagnosed KOA in China. Methods: This was a longitudinal study. We used health insurance claims of 17.7 million adults from 2008-2017 to identify people with KOA. Trends in prevalence and incidence were analyzed using joinpoint regression. Results: We identified 2,447,990 people with KOA in Beijing, 60% of which were women. The 10-year average age-standardized prevalence and incidence of KOA was, respectively, 4.6% and 25.2 per 1000 person-years. Prevalence increased with age, surging after 55 years old. The average crude prevalence was 13.2% for people over 55 years old. The prevalence showed an increasing trend from 2008 to 2017, including a period of rapid rise from 2008 to 2011 (p < 0.05); the increase in prevalence was greatest in people under 35 years old (p < 0.05). Conclusion: Our analyses showed that the annual prevalence rate of KOA increased significantly from 2008 to 2017 in China. We need to increase our attention to women and the elderly over 55 years old, and also be alert to the younger trend of incidence of KOA.

Childhood adversity is linked to adult health among African Americans via adolescent weight gain and effects are genetically moderated

Identifying the mechanisms linking early experiences, genetic risk factors, and their interaction with later health consequences is central to the development of preventive interventions and identifying potential boundary conditions for their efficacy. In the current investigation of 412 African American adolescents followed across a 20-year period, we examined change in body mass index (BMI) across adolescence as one possible mechanism linking childhood adversity and adult health. We found associations of childhood adversity with objective indicators of young adult health, including a cardiometabolic risk index, a methylomic aging index, and a count of chronic health conditions. Childhood adversities were associated with objective indicators indirectly through their association with gains in BMI across adolescence and early adulthood. We also found evidence of an association of genetic risk with weight gain across adolescence and young adult health, as well as genetic moderation of childhood adversity's effect on gains in BMI, resulting in moderated mediation. These patterns indicated that genetic risk moderated the indirect pathways from childhood adversity to young adult health outcomes and childhood adversity moderated the indirect pathways from genetic risk to young adult health outcomes through effects on weight gain during adolescence and early adulthood.

Differential Synovial CGRP/RAMP1 Expression in Men and Women With Knee Osteoarthritis

Background

Female patients with osteoarthritis report more severe knee pain compared to men. However, the mechanism underlying sex differences in pain remains unclear. We previously found that calcitonin gene-related peptide (CGRP) was expressed in synovial tissue and that this localization may play a role in pain associated with knee osteoarthritis (KOA). Several animal studies have shown that the expression of CGRP and its receptor (receptor activity modifying protein 1, RAMP1) differs by sex. Here, we investigated synovial CGRP and RAMP1 expression in male and female patients with KOA.

Methods

Synovial tissue (ST) was harvested from male and female subjects (n=30 each) with radiographically confirmed unilateral Kellgren/Lawrence grade 3-4 KOA during total knee arthroplasty. Patients’ subjective pain severity was scored on a 0 to 10 cm visual analog scale (VAS). We compared the expression of CGRP and RAMP1 in ST from men and women and examined the correlation between mRNA levels of CGRP and RAMP1 and pain severity.

Results

Synovial expression of CGRP and RAMP1 was significantly elevated in women compared to men (CGRP, P=0.017; RAMP1, P=0.028). While CGRP expression was positively correlated with pain severity in females (ρ=0.443, P=0.014), no correlation was observed in men (ρ=-0.021, P=0.913). RAMP1 expression was not correlated with pain severity in either men or women (male, ρ=-0.114, P=0.939; female, ρ=-0.047, P=0.807).

Conclusion

CGRP and RAMP1 expression levels differ between men and women. Differential CGRP levels may suggest the presence of different pain mechanisms in men and women with KOA.

Global Deletion of Pannexin 3 Resulting in Accelerated Development of Aging-Induced Osteoarthritis in Mice

OBJECTIVE

Osteoarthritis (OA) results in pathologic changes in the joint tissue. The mechanisms driving disease progression remain largely unclear, and thus disease-modifying treatments are lacking. Pannexin 3 (Panx3) was identified as a potential mediator of cartilage degeneration in OA, and our previous study in mice indicated that deletion of the Panx3 gene delayed surgically induced cartilage degeneration. This study was undertaken to examine the role of Panx3 in other OA subtypes, particularly primary OA during aging, in a mouse model of aging-induced OA.

METHODS

Wild-type (WT) and Panx3^-/- C57BL/6J (Black-6) mice, ages 18-24 months, were analyzed by micro-computed tomography to investigate bone mineral density and body composition. Joints were harvested from the mice, and histopathologic analysis of the joint tissue for OA development was conducted with a specific focus on changes in articular cartilage, subchondral bone, and synovial tissue.

RESULTS

Global loss of Panx3 in aging mice was not associated with increased mortality or changes in body composition. Mice lacking Panx3 had shorter appendicular skeletons than WT mice, but overall the body compositions appeared quite similar. Panx3 deletion dramatically accelerated cartilage degeneration and subchondral bone thickening with aging in both 18-month-old and 24-month-old mice, while promoting synovitis in 18-month-old mice.

CONCLUSION

These observations in a mouse model of OA suggest that Panx3 has a protective role against the development of primary aging-associated OA. It appears that Panx3 has opposing context-specific roles in joint health following traumatic injury versus that associated with aging. These data strongly suggest that there are differences in the molecular pathways driving different subtypes of OA, and therefore a detailed understanding of these pathways could directly improve strategies for OA diagnosis, therapy, and research.

Towards sex-specific osteoarthritis risk models: evaluation of risk factors for knee osteoarthritis in males and females

Objectives

The aim of this study was to identify sex-specific prevalence and strength of risk factors for the incidence of radiographic knee OA (incRKOA).

Methods

Our study population consisted of 10 958 Rotterdam Study participants free of knee OA in one or both knees at baseline. One thousand and sixty-four participants developed RKOA after a median follow-up time of 9.6 years. We estimated the association between each available risk factor and incRKOA using sex stratified multivariate regression models with generalized estimating equations. Subsequently, we statistically tested sex differences between risk estimates and calculated the population attributable fractions (PAFs) for modifiable risk factors.

Results

The prevalence of the investigated risk factors was, in general, higher in women compared with men, except that alcohol intake and smoking were higher in men and high BMI showed equal prevalence. We found significantly different risk estimates between men and women: high level of physical activity [relative risk (RR) 1.76 (95% CI: 1.29–2.40)] or a Kellgren and Lawrence score 1 at baseline [RR 5.48 (95% CI: 4.51–6.65)] was higher in men. Among borderline significantly different risk estimates was BMI ≥27, associated with higher risk for incRKOA in women [RR 2.00 (95% CI: 1.74–2.31)]. The PAF for higher BMI was 25.6% in women and 19.3% in men.

Conclusion

We found sex-specific differences in both presence and relative risk of several risk factors for incRKOA. Especially BMI, a modifiable risk factor, impacts women more strongly than men. These risk factors can be used in the development of personalized prevention strategies and in building sex-specific prediction tools to identify high risk profile patients.

Association of isometric quadriceps strength with stride and knee kinematics during gait in community dwelling adults with normal knee or early radiographic knee osteoarthritis

BACKGROUND

Identifying indicators of early knee osteoarthritis is important for preventing the onset and/or progression of the disease. Although low quadriceps strength and changes in stride and knee kinematics during gait have been suggested as possible indicators, their relevance and relationships have not been fully examined. This study aimed to analyze the association of quadriceps strength with stride and knee kinematics during gait in adults with normal knee or early knee osteoarthritis.

METHODS

A total of 881 knees from 474 community dwelling adults (238 males and 236 females) were included. Radiographic images of the knee in standing position were obtained, and grading of knee osteoarthritis was classified. Isometric quadriceps strength was measured using a force detector device. Three-dimensional knee kinematics during gait was obtained by a motion capture system. Sex-based difference of quadriceps strength, stride and knee kinematics during gait was evaluated by multiple comparison among grades by sex and multiple regression of quadriceps strength was analyzed by stride and knee kinematics during gait.

FINDINGS

Stride length and quadriceps strength were significantly reduced with higher grade in both sexes, and changes in knee kinematics during gait differed by sex from early knee osteoarthritis. Quadriceps strength in both sexes was significantly correlated with changes in stride length and knee kinematics during gait.

INTERPRETATION

Improving quadriceps strength in early knee osteoarthritis was related with maintaining gait ability and restraining abnormal knee kinematics during gait. This may help to develop clinical approaches to prevent the onset and/or progression of knee osteoarthritis.

Is a Combination of Exercise and Dry Needling Effective for Knee OA?

OBJECTIVE

To assess the effectiveness of adding dry needling (DN) to an exercise program on pain intensity and disability in patients with knee osteoarthritis.

DESIGN

Double-blind randomized clinical trial with one-year follow-up.

SETTING

Older adults in a multicenter study.

SUBJECTS

Sixty-two patients with knee osteoarthritis were randomly allocated into one of two groups: exercise plus DN (exercise + DN; N = 31) or exercise plus sham DN (exercise + sham DN; N = 31).

METHODS

Participants received six sessions of either DN or sham DN over the leg muscles related to knee pain from osteoarthritis plus a supervised exercise program. We evaluated between-group differences in terms of the numerical pain rating scale (NPRS) and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score. We used the EuroQol Group 5-Dimension Self-Report Questionnaire, Barthel Index, Timed Up & Go Test, and Global Rating of Change Scale to examine between-group differences for health-related quality of life, functional status evaluation, balance assessment, and clinical progress, respectively.

RESULTS

The groups were not different in terms of pain intensity (0.32 points, 95% confidence interval [CI] = -1.12 to 1.18, P = 0.92) or WOMAC score (0.29 points, 95% CI = -6.16 to 6.74, P = 0.92) at one year. Both groups presented within-group differences at all follow-up periods (F = 28.349, P < 0.0001, ηp2 = 0.32) on secondary outcomes. Nevertheless, 90.3% of the DN group had reduced medication consumption vs only 26.3% in the sham DN group.

CONCLUSIONS

The inclusion of DN to an exercise program does not reduce pain or disability in patients with knee osteoarthritis.

The Longitudinal Relationship Between Physical Activity and Joint Space Narrowing: 48-Month Follow-Up Data from the Osteoarthritis Initiative

OBJECTIVE

To determine whether amount of physical activity (PA) is a determinant of joint space narrowing (JSN) worsening over 48-months in participants with knee osteoarthritis (OA).

METHODS

Data were obtained from the Osteoarthritis Initiative. PA, measured using the Physical Activity Scale for the Elderly (PASE), was defined as the mean value of the annual measurements conducted prior to development of worsening JSN. Worsening JSN was defined as at least a partial grade increase in OARSI JSN score over 48 months, in comparison with baseline. Restricted cubic spline (RCS) function was used to group participants based on the linear association between PA and JSN worsening. A pooled logistic regression model was used to evaluate the association between PA and JSN worsening adjusted for confounders.

RESULTS

2,167 participants were included. In total, 625 (28.8%) participants had JSN worsening over 48 months. Compared with PASE score of 140-180, PASE scores of 100-140 and >220 associated with an increased risk of JSN worsening in men with OR (95% CI) of 1.73 (1.07, 2.81) and 1.83 (1.14, 2.93) respectively. Similarly, in participants with Kellgren and Lawrence grade 2, compared with a PASE score of 140-180, PASE score of <100 and >220 were associated with increased risks of JSN worsening, with OR (95% CIs) of 1.69 (1.13, 2.54) and 1.64 (1.05, 2.56) respectively.

CONCLUSION

Compared to moderate PA, higher or lower amounts of PA are associated with elevated risk for JSN worsening in men and in participants with KL grade 2 knees.

The implications of an aging population and increased obesity for knee arthroplasty rates in Sweden: a register-based study

Background and purpose - Total knee arthroplasty (TKA) has increased substantially in Sweden. We quantified the relative risk for TKA in the Swedish population for different BMI categories and age groups to investigate whether the continued increase in TKA is attributable to increased prevalence of obesity and elderly people in the population, and to put forward model predictions for coming needs for TKA. Patients and methods - We used the Swedish Nationwide Health Survey (SNHS) and the Swedish Knee Arthroplasty Register (SKAR) 2009-2015 to calculate the relative risk (RR) of TKA by age (middle-aged 45-64 years and elderly 65-84 years) and BMI (BMI 18.5-24.9 normal weight; BMI 25.0-29.9 overweight; BMI > 30 obese). The RR for TKA was applied to the demographic forecasts for the Swedish population as a forecasting model. Results - Population size increased 5.2% from 2009 to 2015 to 40,000 middle-aged and 250,000 elderly, and the prevalence of obesity increased from 16% to 18% in these 2 age categories. Compared with those of normal weight, the RR for TKA was 2.7 (95% CI 2.5-3.0) higher for the overweight and 7.3 (6.7-8.0) higher for the obese, aged 45-64. The corresponding figures for individuals aged 65-84 were 2.1 (2.0-2.2) and 4.0 (3.8-4.3) higher, respectively. The changes in the prevalence of obesity and an increase in the elderly population accounted for an estimated increase of 1,700 TKAs over the 7 years. Interpretation - The increase in obesity frequency and the rise in the population of middle-aged and elderly may, to some extent, explain the rise in TKA utilization in Sweden.

Proximal fibular osteotomy: Systematic review on its outcomes

BACKGROUND

The morbidity and burden of knee osteoarthritis affecting millions of lives worldwide has created a constant pursuit in finding the ideal treatment for knee osteoarthritis. There has been a paradigm shift in the surgical treatment of osteoarthritis ever since the initial description of Volkmann’s tibial osteotomy. This review focuses on one such recent procedure, the proximal fibular osteotomy (PFO) for medial compartment knee osteoarthritis. This review encompasses the history, evidence, risk factors, outcomes and technical considerations of PFO.

AIM

To understand the evidence and its techniques, and whether this could be an alternative solution to the problem of knee osteoarthritis in the developing world.

METHODS

The phrases “proximal fibular osteotomy” and “knee osteoarthritis” were searched (date of search December 20, 2019) on PubMed to identify articles evaluating the biomechanical and clinical outcomes of PFO in patients with knee osteoarthritis. A total of 258 were retrieved. After reviewing the summary of the texts, 22 articles written in English were marked for abstract review. Articles that were case studies or cadaver experiments were excluded. The abstracts of the remaining articles were read, and only those that focused on the history, outcomes of case studies and technical considerations of PFO were included in the review. A total of 12 articles were included in this review.

RESULTS

At least six studies reported improvement in the visual analogue scale(VAS) from the average preoperative VAS score [6.32, 95% confidence interval (CI) = (4.05, 8.59)] to average postoperative VAS score [1.23, 95%CI: (-1.20, 3.71)], which was statistically significant. Similarly, the American Knee Society Score (KSS) functional score improved from an average preoperative KSS functional score [43.11, 95%CI: (37.83, 48.38)] to postoperative KSS functional score [66.145, 95%CI: (61.94, 70.35)], which was statistically significant. The femorotibial angle improved by around 7^º, and the hip knee ankle angle improved by around 6^º.

CONCLUSION

With the existing data, it seems that PFO is a viable option for treating medial joint osteoarthritis in selected patients. Long term outcome studies and progression of disease pathology are some of the important parameters that need to be addressed by use of multicenter randomized controlled trials.

Total Serum Testosterone and Western Ontario and McMaster Universities Osteoarthritis Index Pain and Function Among Older Men and Women With Severe Knee Osteoarthritis

OBJECTIVE

To investigate whether serum total testosterone level is associated with knee pain and function in men and women with severe knee osteoarthritis (OA).

METHODS

We enrolled 272 adults age ≥60 years (mean ± SD age 70.4 ± 4.4 years, 53% women) who underwent unilateral total knee replacement (TKR) due to severe knee OA. Serum testosterone levels and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) pain and function of the operated and contralateral knee were measured at 6-8 weeks after surgery. At the nonoperated knee, 56% of participants had radiographic knee OA with a Kellgren/Lawrence grade ≥2. Cross-sectional analyses were performed by sex and body mass index (BMI) subgroups, using multivariable regression adjusted for age, physical activity, and BMI.

RESULTS

At the operated knee, higher testosterone levels were associated with less WOMAC pain in men (B = -0.62, P = 0.046) and women (B = -3.79, P = 0.02), and less WOMAC disability scores in women (B = -3.62, P = 0.02) and obese men (B = -1.99, P = 0.02). At the nonoperated knee, testosterone levels were not associated with WOMAC pain in men or women, but higher testosterone levels were associated with less disability in women (B = -0.95, P = 0.02). Testosterone levels were inconsistently associated with pain and disability in BMI subgroups among men. Only among obese women, testosterone levels were inversely associated with radiographic knee OA (odds ratio = 0.10, P = 0.003).

CONCLUSION

Higher total testosterone levels were associated with less pain in the operated knee in men and women undergoing TKR and less disability in women. At the nonoperated knee, higher testosterone levels were inconsistently associated with less pain and disability.

Impact of smoking on femorotibial and hip osteoarthritis progression: 3-year follow-up data from the KHOALA cohort

OBJECTIVES

To evaluate the clinical and structural impact of smoking on knee and hip osteoarthritis at baseline and after 3years.

METHODS

Observational data on the progressive effects of smoking at baseline and after 3years were collected from The Knee and Hip Osteoarthritis Long-Term Assessment cohort comprising a French population of patients aged 40-75years with symptomatic lower limb osteoarthritis. Clinical (the Western Ontario and McMaster Universities Arthritis Index and Harris scores) and structural (radiography for osteophyte detection and joint-space narrowing assessment) were conducted. The tobacco usage categories were 'never smoker', 'former smoker', and 'current smoker'.

RESULTS

Of the 873 subjects included, 215 (25%) were former smokers and 119 (14%) were current smokers. Multivariate analyses revealed that former and current smokers had fewer knee osteophytes in the medial compartment at baseline (odds ratio [OR]=0.64 [0.41-0.99] and 0.63 [0.36-1.11], respectively), lower osteophyte development in the lateral condyle after 3years (OR=011 [0.03-0.45] and 0.15 [0.03-0.97]), and lower osteophyte development in the lateral tibial plateau after 3years (OR=0.22 [0.06-0.75] and 0.68 [0.14-3.35]). Higher tobacco consumption and longer duration of consumption were significantly associated with fewer knee osteophytes at baseline and lower osteophyte development at 3years.

CONCLUSION

Although cigarette smoking did not influence knee function, pain, or the need for replacement surgery, current and former smokers developed fewer osteophytes. This relationship may be linked to the quantity and duration of consumption. Our results provide further insight into the smoking-related pathophysiology of osteoarthritis.

Combined diabetes and arthritis are associated with declined gait speed

This study investigated the association of combined arthritis and diabetes, diabetes only, and arthritis only compared with neither with gait speed in the general population. This cross-sectional study included data from the second wave of Midlife in the United States-2 (MIDUS 2) project 4: Biomarker Project, 2004-2009. The MIDUS 2 biomarker project included 1255 individuals aged between 34 and 84 years. Participants were categorized into four groups: combined arthritis and diabetes, diabetes only, arthritis only, or neither. The main outcome measure was gait speed measured by the 50-ft walk test. Covariates included age, gender, body mass index (BMI), depression symptoms, and number of chronic conditions/symptoms. A total of 1255 participants were included with mean age 54.52 ± 11.71, of those 713 (56.8%) participants were females. The results showed that combined arthritis and diabetes was significantly associated with a greater decline in gait speed (B = - 0.11, 95% confidence interval (CI) [- 0.17 to - 0.6], p < 0.001). Arthritis and diabetes were independently significantly associated with decreased gait speed (B = - 0.072, 95% CI [- 0.10 to - 0.043], p < 0.001), (B = - 0.064, 95% CI [- 0.12 to - 0.012], p = 0.015), respectively. Combined arthritis and diabetes was associated with a greater decline in gait speed compared with diabetes only, arthritis only, or neither group. Key Points • Combined arthritis and diabetes were associated with declined gait speed. • Gait speed did not differ between people with arthritis compared with people with diabetes. • We recommended including gait speed assessment in regular clinical visits to capture gait speed declines for further health assessments.

Relation of Patellofemoral Joint Alignment, Morphology, and Radiographic Osteoarthritis to Frequent Anterior Knee Pain: Data from the Multicenter Osteoarthritis Study

OBJECTIVE

Patellofemoral (PF) alignment and trochlear morphology are associated with PF osteoarthritis (OA) and knee pain, but whether they are associated with localized anterior knee pain is unknown, which is believed to be a symptom specific to PF joint pathology. We therefore aimed to evaluate the relation of PF alignment and morphology, as well as PFOA and tibiofemoral OA, to anterior knee pain.

METHODS

The Multicenter Osteoarthritis Study is a cohort study of individuals with, or at risk for, knee OA. We evaluated cross-sectional associations of PF alignment, trochlear morphology, and PF and tibiofemoral radiographic OA, with localized anterior knee pain (defined with a pain map). We used 2 approaches: a within-person knee-matched evaluation of participants with unilateral anterior knee pain (conditional logistic regression), and a cohort approach comparing those with anterior knee pain to those without (binomial regression).

RESULTS

With the within-person knee-matched approach (n = 110; 64% women, mean age 70 years, body mass index [BMI] 30.9), PF alignment, morphology, and tibiofemoral OA were not associated with unilateral anterior knee pain. Radiographic PFOA was associated with pain, odds ratio 5.3 (95% confidence interval [95% CI] 1.6-18.3). Using the cohort approach (n = 1,818; 7% of knees with anterior knee pain, 59% women, mean age 68 years, BMI 30.4), results were similar: only PFOA was associated with pain, with a prevalence ratio of 2.2 (95% CI 1.4-3.4).

CONCLUSION

PF alignment and trochlear morphology were not associated with anterior knee pain in individuals with, or at risk for, knee OA. Radiographic PFOA, however, was associated with pain, suggesting that features of OA, more so than mechanical features, may contribute to localized symptoms.

Pathogenesis of Osteoarthritis: Risk Factors, Regulatory Pathways in Chondrocytes, and Experimental Models

As the most common chronic degenerative joint disease, osteoarthritis (OA) is the leading cause of pain and physical disability, affecting millions of people worldwide. Mainly characterized by articular cartilage degradation, osteophyte formation, subchondral bone remodeling, and synovial inflammation, OA is a heterogeneous disease that impacts all component tissues of the articular joint organ. Pathological changes, and thus symptoms, vary from person to person, underscoring the critical need of personalized therapies. However, there has only been limited progress towards the prevention and treatment of OA, and there are no approved effective disease-modifying osteoarthritis drugs (DMOADs). Conventional treatments, including non-steroidal anti-inflammatory drugs (NSAIDs) and physical therapy, are still the major remedies to manage the symptoms until the need for total joint replacement. In this review, we provide an update of the known OA risk factors and relevant mechanisms of action. In addition, given that the lack of biologically relevant models to recapitulate human OA pathogenesis represents one of the major roadblocks in developing DMOADs, we discuss current in vivo and in vitro experimental OA models, with special emphasis on recent development and application potential of human cell-derived microphysiological tissue chip platforms.

Correlation between radiographic knee osteoarthritis and lifetime cigarette smoking amount in a Korean population: A cross-sectional study

Although the inverse correlation between smoking and degenerative arthritis is controversial, quantitative analysis of the correlation between lifetime cigarette smoking amount and degenerative arthritis has not been performed. We investigated the correlation between knee radiographic osteoarthritis (ROA) and lifetime cigarette smoking amount in the general population.This cross-sectional study used the Fifth and Sixth Korean National Health and Nutrition Examination Survey (2010-2013) data. Subjects included 11,638 community-dwelling adults aged ≥50 years. Knee ROA was defined as a Kellgren/Lawrence grade ≥2 on plain radiography. Lifetime cigarette smoking amount was calculated in terms of pack-year and further divided into quartile groups. Independent correlation between smoking and knee ROA was determined using odds ratios (OR) adjusted for age, sex, obesity, physical activity, and household income on multivariate logistic regression analysis.Knee ROA prevalence was 37.3%; prevalence of lifetime cigarette smokers was 26.0%. Subjects with knee ROA had higher mean age, female sex ratio, and body mass index but lower physical activity level. The adjusted logistic regression model revealed that female sex (OR, 2.110; 95% confidence interval [CI], 1.895-2.349) was significantly associated with knee ROA. Older age, obesity, and lower household income were positively correlated with knee ROA. Second-and fourth-quartile groups of smokers had the lower ROA prevalence than never-smokers (OR, 0.800; 95% CI, 0.643-0.99; OR, 0.812; 95% CI, 0.684-0.965, respectively).An inverse correlation with knee ROA was confirmed in mid-light to heavy smokers. Prospective studies are needed to reveal whether knee ROA involves smoking.