What if we prevent obesity? Risk reduction in knee osteoarthritis estimated through a meta-analysis of observational studies

Causal associations of central and peripheral risk factors with knee osteoarthritis: a longitudinal and Mendelian Randomisation study using UK Biobank data

ABSTRACT

Our aim was to investigate relative contributions of central and peripheral mechanisms to knee osteoarthritis (OA) diagnosis and their independent causal association with knee OA. We performed longitudinal analysis using data from UK-Biobank participants. Knee OA was defined using International Classification of Diseases manual 10 codes from participants' hospital records. Central mechanisms were proxied using multisite chronic pain (MCP) and peripheral mechanisms using body mass index (BMI). Odds ratios (ORs) and 95% confidence intervals (CIs) were estimated, and proportional risk contribution (PRC) was estimated from receiver-operator-characteristic (ROC) analysis. To estimate the causal effects, we performed 2-sample multivariable Mendelian Randomisation (MR) analysis. We selected genetic instruments from the largest Genome Wide Association Study of BMI (N = 806,834) and MCP (N = 387,649) and estimated the instruments genetic associations with knee OA in the largest available dataset (62,497 cases and 333,557 control subjects). The multivariable MR was performed using modified inverse-variance weighting methods. Of the 203,410 participants, 6% developed knee OA. Both MCP (OR 1.23, 95% CI; 1.21-1.24) and BMI (1.10, 95% CI; 1.10-1.11) were associated with knee OA diagnosis. The PRC was 6.9% (95% CI; 6.7%-7.1%) for MCP and 21.9% (95% CI; 21.4%-22.5%) for BMI; the combined PRC was 38.8% (95% CI; 37.9%-39.8%). Body mass index and MCP had independent causal effects on knee OA (OR 1.76 [95% CI, 1.64-1.88] and 1.83 [95% CI, 1.54-2.16] per unit change, respectively). In conclusion, peripheral risk factors (eg, BMI) contribute more to the development of knee OA than central risk factors (eg, MCP). Peripheral and central factors are independently causal on knee OA.

Cost of overweight, obesity, and related complications in Switzerland 2021

Background

The prevalence of obesity has increased significantly in recent decades. Today, it is estimated that more than one-third of the world's population has overweight or obesity, rendering it one of the most significant global health concerns. This article provides a current estimate of the direct costs associated with managing overweight and obesity, including treatment of related complications, among adolescents (≥15 years) and adults in Switzerland.

Methods

Prevalence of overweight and obesity based on the BMI reported in the 2017 Swiss Health Survey was extrapolated to 2021. Systematic literature searches were performed to identify treatment costs and epidemiological data of obesity-related complications and costs were extrapolated to 2021. Costing methodology was based on available source data for individual related complications. Treatment costs for complications attributable to overweight and obesity were estimated by applying their population attributable fraction (PAF).

Results

More than 3.1 million inhabitants of Switzerland aged ≥15 years met the criteria for overweight or obesity in 2021. The prevalence of overweight increase over the past decades from 30.4% in 1992 to 41.9% in 2017 while prevalence of obesity doubled from 5.4 to 11.3%. Overall, the total attributable costs of overweight and obesity caused by seven assessed obesity-related complications (asthma, coronary heart disease, depression, diabetes mellitus, hypertension, osteoarthritis, and stroke) are estimated at CHF 3657-5208 million with most of the costs (97-98%) caused by the assessed obesity-related complications. Only 2-3% of the total costs were attributable to the combined direct management of overweight and obesity by bariatric surgery (CHF 83 million), pharmacological therapy (CHF 26 million) and dietary counseling (CHF 18 million).

Conclusion

Overweight and obesity impose a significant cost impact on the Swiss healthcare system, accounting for 4.2-6.1% of total healthcare expenditures in 2021. Notably, direct treatment of overweight and obesity accounts for only 0.08-0.18% of the total healthcare expenditures. The analysis also revealed a significant lack of available health economic evidence, necessitating the use of assumptions and approximations in this estimation. This is noteworthy, as respective data would be available in healthcare systems but are either unpublished or inaccessible.

Platelet-Rich Plasma for Knee Osteoarthritis: What Does the Evidence Say?

The utilization of platelet-rich-plasma as a therapeutic intervention for knee osteoarthritis has gained immense attention since 2008. The increase in the number of scientific publications dedicated to this area can be attributed to the majority of favorable results reported in clinical trials and basic science studies. However, despite the growing evidence, the use of platelet-rich plasma in clinical practice still poses controversial aspects. The potential mechanisms of action described for platelet-rich-plasma so far indicate that it could serve as a disease-modifying drug, acting to counteract important aspects of knee osteoarthritis pathophysiology (cartilage breakdown, inflammation, and bone remodeling). Nevertheless, its efficacy in slowing down the progression of knee osteoarthritis remains unproven. While inconsistencies have been noted, the majority of controlled clinical trials and meta-analyses advocate for the utilization of platelet-rich-plasma in treating knee osteoarthritis, as it has demonstrated greater efficacy than hyaluronic acid and placebo, with a follow-up of at least 1 year. Despite advancements made in certain areas, significant diversity persists regarding the formulations used, therapeutic regimen, extended follow-up periods, patient selection, and assessment of clinically relevant outcomes. Consequently, the leading clinical practice guidelines do not recommend its use. In light of the emerging evidence, this narrative review aims to provide an objective evaluation of the recent available scientific literature (last 5 years) focused on randomized clinical trials and meta-analyses to present a current overview of the topic.

Association Between Change in Body Mass Index and Knee and Hip Replacements: A Survival Analysis of Seven to Ten Years Using Multicohort Data

OBJECTIVE

To define the association between change in body mass index (BMI) and the risk of knee and hip replacement.

METHODS

We used data from 3 independent cohort studies: the Osteoarthritis Initiative (OAI), the Multicenter Osteoarthritis Study (MOST), and the Cohort Hip and Cohort Knee (CHECK) study, which collected data from adults (45-79 years of age) with or at risk of clinically significant knee osteoarthritis. We conducted Cox proportional hazards regression analysis with clustering of both knees and hips per person to determine the association between change in BMI (our exposure of interest) and the incidence of primary knee and hip replacement over 7-10 years' follow-up. Change in BMI (in kg/m2 ) was calculated between baseline and the last follow-up visit before knee or hip replacement, or for knees and hips that were not replaced, the last follow-up visit.

RESULTS

A total of 16,362 knees from 8,181 participants, and 16,406 hips from 8,203 participants, were eligible for inclusion in our knee and hip analyses, respectively. Change in BMI was positively associated with the risk of knee replacement (adjusted hazard ratio [HRadj ] 1.03 [95% confidence interval (95% CI) 1.00-1.06]) but not hip replacement (HRadj 1.00 [95% CI 0.95-1.04]). The association between change in BMI and knee replacement was independent of participants' BMI category at baseline (i.e., normal, overweight, or obese).

CONCLUSION

Public health strategies incorporating weight loss interventions could reduce the burden of knee but not hip replacement surgery.

A causal relationship between childhood obesity and risk of osteoarthritis: results from a two-sample Mendelian randomization analysis

PURPOSE

It has been found that childhood obesity (CO) may play an important role in the onset and progression of osteoarthritis (OA). Thus we conducted this mendelian randomisation analysis (MR) to evaluate the causal association between childhood obesity and osteoarthritis.

METHODS

Instrumental variables (IVs) were obtained from publicly available genome-wide association study datasets. The leave-one-out sensitivity test, MR Pleiotropy RESidual Sum and Outlier test (MR-PRESSO), and Cochran's Q test were used to confirm the heterogeneity and pleiotropy of identified IVs, then five different models, including the inverse variance weighted model (IVW), weighted median estimator model (WME), weighted model-based method (WM), MR-Egger regression model (MER), and MR-Robust Adjusted Profile Score (MRAPS) were applied in this MR analysis.

RESULTS

After excluding all outliers identified by the MR-PRESSO test, no evident directional pleiotropy was found. Significant heterogeneity was found in the secondary MR and as a result, the multiplicative random-effect model was used. Significant causal association between CO and OA (OR 1.0075, 95% CI [1.0054, 1.0010], p = 8.12 × 10^-13). The secondary MR also revealed that CO was causally associated with knee OA (OR 1.1067, 95% CI [1.0769, 1.1373], p = 3.30 × 10^-13) and hip OA (OR 1.1272, 95% CI [1.0610, 1.1976], p = 1.07 × 10^-4). The accuracy and robustness of these findings were confirmed by sensitivity tests.

CONCLUSION

There appears to be a causal relationship between childhood obesity and OA. Our results indicate that individuals with a history of childhood obesity require specific clinical attention to prevent the development of knee and hip OA.

Analysis of correlation between the consumption of beverages and the risk of radiographic knee osteoarthritis in Korean people: A cross-sectional study using the Fifth Korea National Health and Nutrition Examination Survey (KNHANES V-1, 2)

The purposes were to analyze correlations between the frequency of beverage drinking (coffee, green tea, milk, and soft drinks) and the presence of radiographic knee osteoarthritis (OA) in relation to sex. We performed this study using the Korea National Health and Nutrition Examination Survey (KHANES V-1, 2). We examined data from 5503 subjects after exclusion. We utilized the food frequency questionnaires from KHANES, and reorganized them into 2 or 3 groups according to the frequency of beverage consumption. We analyzed the relationship between radiographic knee OA and beverage consumption statistically after adjusting confounding factors with multivariable logistic regression analysis. Knee OA was inversely associated with coffee consumption only in women (P < .05). The odds ratio of knee OA was lower in those who drank at least a cup of coffee than in those who did not drink coffee in women (P for trend < .05). However, there was no significant linear trend of the odds ratio of each group in both sexes for drinking other beverages. As the coffee consumption increased, the radiographic knee OA group showed decreasing linear trend only in women. However, other beverages did not show a significant relation to the radiographic knee OA in both sexes.

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.

Fibromyalgia and obesity: A comprehensive systematic review and meta-analysis

INTRODUCTION

Obesity has been associated with several complications, including musculoskeletal disorders. Aim of the present systematic review was to identify all available evidence on the relationship between fibromyalgia (FM) and obesity, including epidemiological association, impact of obesity on FM severity and effect of weight loss strategies on FM symptoms.

METHODS

MedLine, Cochrane Central Register of Controlled Trials and Web of Science databases were searched up to September 2020 to identify eligible articles. Data from studies reporting the prevalence of obesity in FM patients were pooled using a random-effects model.

RESULTS

After removal of duplicate records, 393 studies proceeded to review. A total of 41 articles were deemed eligible for inclusion in final synthesis. Quality assessment revealed that the overall risk of bias was high. The overall prevalence of obesity in FM was 35.7% (95% CI: 31.8 - 39.9%), with higher figures reported for USA. The majority of studies included demonstrated that obesity is associated with different domains of the disorder, including composite measures of activity, pain severity, tender point count, stiffness, fatigue, physical functioning/disability, sleep, cognitive dysfunction, and quality of life; the strength of correlation was weak on average. Inconsistent data were available regarding the correlation with depression and anxiety. Only few studies addressed the effect of therapeutic weight loss in FM, either by bariatric surgery, diet/exercise combination or behavioral weight loss, providing preliminary evidence for a potential benefit of weight loss in ameliorating FM symptoms.

CONCLUSIONS

Available data support a potential interplay between obesity and FM-related symptoms. Weight management should be encouraged in patients with FM.

Can intermittent fasting be helpful for knee osteoarthritis?

Obesity and Knee Osteoarthritis (KOA) has a proven association. The obese individuals are likely to have early and more severe KOA, and the complications and overall results of surgery are also inferior. Hence, weight reduction is of paramount importance for these individuals. Due to the inability to do intense physical activities, these individuals cannot lose weight and instead perpetually kept gaining weight. Hence, intermittent fasting as a non-operative means of weight reduction is an attractive and viable option. This review article would help sensitize the Orthopaedic Surgeons about fasting in weight reduction and assisting the KOA. Hence, the choice of intermittent fasting should be offered to obese patients with KOA for weight reduction.

To what extent is severe osteoarthritis preventable? Occupational and non-occupational risk factors for knee and hip osteoarthritis

OBJECTIVES

To explore the relative contribution of cumulative physical workload, sociodemographic and lifestyle factors, as well as prior injury to hospitalization due to knee and hip OA.

METHODS

We examined a nationally representative sample of persons aged 30-59 years, who participated in a comprehensive health examination (the Health 2000 Study). A total of 4642 participants were followed from mid-2000 to end-2015 for the first hospitalization due to knee or hip OA using the National Hospital Discharge Register. We examined the association of possible risk factors with the outcome using a competing risk regression model (death was treated as competing risk) and calculated population attributable fractions for statistically significant risk factors.

RESULTS

Baseline age and BMI as well as injury were associated with the risk of first hospitalization due to knee and hip OA. Composite cumulative workload was associated with a dose-response pattern with hospitalizations due to knee OA and with hospitalizations due to hip OA at a younger age only. Altogether, prior injury, high BMI and intermediate to high composite cumulative workload accounted for 70% of hospitalizations due to knee OA. High BMI alone accounted for 61% and prior injury only for 6% of hospitalizations due to hip OA.

CONCLUSION

Our results suggest that overweight/obesity, prior injury and cumulative physical workload are the most important modifiable risk factors that need to be targeted in the prevention of knee OA leading to hospitalization. A substantial proportion of hospitalizations due to hip OA can be reduced by controlling excess body weight.

Methodological quality of systematic reviews on interventions for osteoarthritis: a cross-sectional study

Background

Healthcare providers need reliable evidence for supporting the adoption of new interventions, of which the source of evidence often originates from systematic reviews (SRs). However, little assessment on the rigor of SRs related to osteoarthritis interventions has been conducted. This cross-sectional study aimed to evaluate the methodological quality and predictors among SRs on osteoarthritis interventions.

Methods

Four electronic databases (Cochrane Database of Systematic Reviews, MEDLINE, Embase, and PsycINFO) were searched, from 1 January 2008 to 10 October 2019. An SR was eligible if it focused on osteoarthritis interventions, and we performed at least one meta-analysis. Methodological quality was assessed using the validated AMSTAR 2 instrument. Multivariate regression analyses were conducted to assess predictors of methodological quality.

Results

In total, 167 SRs were included. The most SRs were non-Cochrane reviews (88.6%), and 54.5% investigated non-pharmacological interventions. Only seven (4.2%) had high methodological quality. Respectively, eight (4.8%), 25 (15.0%), and 127 (76.0%) SRs had moderate, low, and critically low quality. Main methodological weaknesses were as follows: only 16.8% registered protocol a priori, 4.2% searched literature comprehensively, 25.7% included lists of excluded studies with justifications, and 30.5% assessed risk of bias appropriately by considering allocation concealment, blinding of patients and assessors, random sequence generation and selective reported outcomes. Cochrane reviews [adjusted odds ratio (AOR) 251.5, 95% confidence interval (CI) 35.5-1782.6], being updates of previous SRs (AOR 3.9, 95% CI 1.1-13.7), and SRs published after 2017 (AOR 7.7, 95% CI 2.8-21.5) were positively related to higher methodological quality.

Conclusion

Despite signs of improvement in recent years, most of the SRs on osteoarthritis interventions have critically low methodological quality, especially among non-Cochrane reviews. Future SRs should be improved by conducting comprehensive literature search, justifying excluded studies, publishing a protocol, and assessing the risk of bias of included studies appropriately.

Serum fatty acid chain length associates with prevalent symptomatic end-stage osteoarthritis, independent of BMI

Higher body mass index (BMI) is associated with osteoarthritis (OA) in both weight-bearing and non-weight-bearing joints, suggesting a link between OA and poor metabolic health beyond mechanical loading. This risk may be influenced by systemic factors accompanying BMI. Fluctuations in concentrations of metabolites may mark or even contribute to development of OA. This study explores the association of metabolites with radiographic knee/hip OA prevalence and progression. A ¹H-NMR-metabolomics assay was performed on plasma samples of 1564 cases for prevalent OA and 2,125 controls collected from the Rotterdam Study, CHECK, GARP/NORREF and LUMC-arthroplasty cohorts. OA prevalence and 5 to 10 year progression was assessed by means of Kellgren-Lawrence (KL) score and the OARSI-atlas. End-stage knee/hip OA (TJA) was defined as indication for arthroplasty surgery. Controls did not have OA at baseline or follow-up. Principal component analysis of 227 metabolites demonstrated 23 factors, of which 19 remained interpretable after quality-control. Associations of factor scores with OA definitions were investigated with logistic regression. Fatty acids chain length (FALen), which was included in two factors which associated with TJA, was individually associated with both overall OA as well as TJA. Increased Fatty Acid chain Length is associated with OA.

Population growth, ageing and obesity do not sufficiently explain the increased utilization of total knee replacement in Australia

BACKGROUND

The utilization of total knee replacement (TKR) has increased significantly. The objective of this study was to assess the impact of changes in population demography (population growth, ageing and gender) and body mass indices (BMIs) on the additional volume of knee replacement surgery undertaken in Australia.

METHODS

Using national data, we compared estimates based on changes in population demography and BMIs to the reported increase in TKR between 2007 and 2017. The costs of additional surgery were estimated using the National Hospital Cost Data Collection.

RESULTS

An additional 25 814 TKRs were performed in 2017 compared to 2007. Contributions from population growth, ageing and changing BMIs were 27.1%, 10.4%, and 6.3%-15.3%, respectively. Other drivers contributed between 47.2% and 56.2%, representing 12 176-14 506 TKRs at a financial cost of A$320.9 million to A$382.3 million per year in 2017.

CONCLUSION

The volume of additional surgery being performed considerably exceeded estimates based on changing population demography and rising rates of obesity. The other drivers of additional TKR utilization will likely have significant implications for the health budget and warrant further investigation. This may involve an examination of the current indications for surgery and the cost-effectiveness of TKR in various settings, reviewing patient expectations and preferences, and assessing the impact of policies which relate to the funding and provision of TKR.

Correlation network analysis shows divergent effects of a long-term, high-fat diet and exercise on early stage osteoarthritis phenotypes in mice

BACKGROUND

Obesity increases knee osteoarthritis (OA) risk through metabolic, inflammatory, and biomechanical factors, but how these systemic and local mediators interact to drive OA pathology is not well understood. We tested the effect of voluntary running exercise after chronic diet-induced obesity on knee OA-related cartilage and bone pathology in mice. We then used a correlation-based network analysis to identify systemic and local factors associated with early-stage knee OA phenotypes among the different diet and exercise groups.

METHODS

Male C57BL/6J mice were fed a defined control (10% kcal fat) or high fat (HF) (60% kcal fat) diet from 6 to 37 weeks of age. At 25 weeks, one-half of the mice from each diet group were housed in cages with running wheels for the remainder of the study. Histology, micro computed tomography, and magnetic resonance imaging were used to evaluate changes in joint tissue structure and OA pathology. These local variables were then compared to systemic metabolic (body mass, body fat, and glucose tolerance), inflammatory (serum adipokines and inflammatory mediators), and functional (mechanical tactile sensitivity and grip strength) outcomes using a correlation-based network analysis. Diet and exercise effects were evaluated by two-way analysis of variance.

RESULTS

An HF diet increased the infrapatellar fat pad size and posterior joint osteophytes, and wheel running primarily altered the subchondral cortical and trabecular bone. Neither HF diet nor exercise altered average knee cartilage OA scores compared to control groups. However, the coefficient of variation was ≥25% for many outcomes, and some mice in both diet groups developed moderate OA (≥33% maximum score). This supported using correlation-based network analyses to identify systemic and local factors associated with early-stage knee OA phenotypes. In wheel-running cohorts, an HF diet reduced the network size compared to the control diet group despite similar running distances, suggesting that diet-induced obesity dampens the effects of exercise on systemic and local OA-related factors. Each of the 4 diet and activity groups showed mostly unique networks of local and systemic factors correlated with early-stage knee OA.

CONCLUSION

Despite minimal group-level effects of chronic diet-induced obesity and voluntary wheel running on knee OA pathology under the current test durations, diet and exercise substantially altered the relationships among systemic and local variables associated with early-stage knee OA. These results suggest that distinct pre-OA phenotypes may exist prior to the development of disease.

Best Evidence Rehabilitation for Chronic Pain Part 5: Osteoarthritis

Osteoarthritis (OA) is a leading cause of chronic pain and disability in older adults, which most commonly affects the joints of the knee, hip, and hand. To date, there are no established disease modifying interventions that can halt or reverse OA progression. Therefore, treatment is focused on alleviating pain and maintaining or improving physical and psychological function. Rehabilitation is widely recommended as first-line treatment for OA as, in many cases, it is safer and more effective than the best-established pharmacological interventions. In this article, we describe the presentation of OA pain and give an overview of its peripheral and central mechanisms. We then provide a state-of-the-art review of rehabilitation for OA pain—including self-management programs, exercise, weight loss, cognitive behavioral therapy, adjunct therapies, and the use of aids and devices. Next, we explore several promising directions for clinical practice, including novel education strategies to target unhelpful illness and treatment beliefs, methods to enhance the efficacy of exercise interventions, and innovative, brain-directed treatments. Finally, we discuss potential future research in areas, such as treatment adherence and personalized rehabilitation for OA pain.

Evaluation of the Effect of Bariatric Surgery-Induced Weight Loss on Knee Gait and Cartilage Degeneration

The objective of the study was to investigate the effects of bariatric surgery-induced weight loss on knee gait and cartilage degeneration in osteoarthritis (OA) by combining magnetic resonance imaging (MRI), gait analysis, finite element (FE) modeling, and cartilage degeneration algorithm. Gait analyses were performed for obese subjects before and one-year after the bariatric surgery. FE models were created before and after weight loss for those subjects who did not have severe tibio-femoral knee cartilage loss. Knee cartilage degenerations were predicted using an adaptive cartilage degeneration algorithm which is based on cumulative overloading of cartilage, leading to iteratively altered cartilage properties during OA. The average weight loss was 25.7±11.0 kg corresponding to a 9.2±3.9 kg/m2 decrease in body mass index (BMI). External knee rotation moment increased, and minimum knee flexion angle decreased significantly (p < 0.05) after weight loss. Moreover, weight loss decreased maximum cartilage degeneration by 5±23% and 13±11% on the medial and lateral tibial cartilage surfaces, respectively. Average degenerated volumes in the medial and lateral tibial cartilage decreased by 3±31% and 7±32%, respectively, after weight loss. However, increased degeneration levels could also be observed due to altered knee kinetics. The present results suggest that moderate weight loss changes knee kinetics and kinematics and can slow-down cartilage degeneration for certain patients. Simulation results also suggest that prediction of cartilage degeneration is subject-specific and highly depend on the altered gait loading, not just the patient's weight.

Consumption of dairy products in relation to the presence of clinical knee osteoarthritis: The Maastricht Study

PURPOSE

Observational studies showed inverse associations between milk consumption and knee osteoarthritis (knee OA). There is lack of information on the role of specific dairy product categories. We explored the association between dairy consumption and the presence of knee osteoarthritis in 3010 individuals aged 40-75 years participating in The Maastricht Study.

METHODS

The presence of knee OA was defined according to a slightly modified version of the American College of Rheumatology (ACR) clinical classification criteria. Data on dairy consumption were appraised by a 253-item FFQ covering 47 dairy products with categorization on fat content, fermentation or dairy type. Multivariable logistic regression analyses were performed to estimate odd ratios (ORs) and 95% confidence intervals (95%CI), while correcting for relevant factors.

RESULTS

427 (14%) participants were classified as having knee OA. Significant inverse associations were observed between the presence of knee OA and intake of full-fat dairy and Dutch, primarily semi-hard, cheese, with OR for the highest compared to the lowest tertile of intake of 0.68 (95%CI 0.50-0.92) for full-fat dairy, and 0.75 (95%CI 0.56-0.99) for Dutch cheese. No significant associations were found for other dairy product categories.

CONCLUSION

In this Dutch population, higher intake of full-fat dairy and Dutch cheese, but not milk, was cross-sectionally associated with the lower presence of knee OA. Prospective studies need to assess the relationship between dairy consumption, and in particular semi-hard cheeses, with incident knee OA.

Role of infrapatellar fat pad in pathological process of knee osteoarthritis: Future applications in treatment

It has been found that obese people have a higher proportion in suffering from osteoarthritis (OA), not only in the weight-bearing joints like knee and hip joints, even in non-weight-bearing joints such as hand joints. One of the reasons is because the large amount of adipose tissue secretes some factors, which can promote the occurrence of arthritis. As an important structure of the knee joint, the infrapatellar fat pad (IPFP) is actually a piece of adipose tissue. The aim of this review is to offer a comprehensive view of the anatomy and physiological characteristics of IPFP and its relationship with the pathological process of OA, indicating the important function of IPFP in OA. At the same time, with the development of adipose derived stem cells in the treatment of OA, owing to its special advantages, the IPFP is becoming a kind of important, minimally invasive fat stem cell source, providing a new approach for the treatment of OA. We hope that this review will offer an overview of all published data regarding the IPFP and will indicate novel directions for future research.

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.

Evaluation of a health trainer–led service for people with knee, hip and back pain

Aims:

Chronic knee, hip and back pain is extremely prevalent. Management guidelines emphasise maintaining physical activity and healthy weight to reduce pain and improve physical and mental wellbeing. Unfortunately, few people receive support to make lifestyle changes. We evaluated whether a health trainer—led ‘joint pain advice’ (JPA) service delivering person-centred lifestyle coaching was feasible, acceptable and effective for people with knee, hip and back pain.

Methods:

Feasibility of delivering a JPA service was assessed by documenting whether the health trainers could deliver JPA and its uptake. Nine health trainers delivered JPA. Participants were offered up to four appointments. At each appointment, health trainers gave people information about their condition, co-developed care plans, suggested self-management strategies and used behavioural change techniques (motivational interviewing, goal-setting and action planning) to increase physical activity and reduce body weight. Pain, function, physical activity and body mass index (BMI) were collected at baseline, 3 weeks, 6 weeks and 6 months. Focus groups captured people’s opinions of the service’s effectiveness, acceptability and usefulness.

Results:

Of the 105 people who enquired about JPA, 85 (81%) used the service, after which their physical activity and function improved, and pain, use of analgesia and BMI decreased. They felt more knowledgeable and better motivated to adopt and maintain healthier behaviours. They attributed these improvements to the JPA service, because of its better consultations and collaborative holistic approach. Only a minority attended all four appointments because they felt they received sufficient advice from the initial appointments. The health trainers gained knowledge and skills to support clients with musculoskeletal conditions.

Conclusions:

Using a holistic, patient-centred approach, health trainers can deliver lifestyle advice to people with chronic knee, hip or back pain safely, effectively and efficiently. The service was popular with recipients and health trainers, and helped people adopt healthier lifestyles that lead to reduced pain and other clinical improvements.

Osteoarthritis

Osteoarthritis is a leading cause of disability and source of societal cost in older adults. With an ageing and increasingly obese population, this syndrome is becoming even more prevalent than in previous decades. In recent years, we have gained important insights into the cause and pathogenesis of pain in osteoarthritis. The diagnosis of osteoarthritis is clinically based despite the widespread overuse of imaging methods. Management should be tailored to the presenting individual and focus on core treatments, including self-management and education, exercise, and weight loss as relevant. Surgery should be reserved for those that have not responded appropriately to less invasive methods. Prevention and disease modification are areas being targeted by various research endeavours, which have indicated great potential thus far. This narrative Seminar provides an update on the pathogenesis, diagnosis, management, and future research on osteoarthritis for a clinical audience.

The projected burden of primary total knee and hip replacement for osteoarthritis in Australia to the year 2030

Background

Comprehensive national joint replacement registries with well-validated data offer unique opportunities for examining the potential future burden of hip and knee osteoarthritis (OA) at a population level. This study aimed to forecast the burden of primary total knee (TKR) and hip replacements (THR) performed for OA in Australia to the year 2030, and to model the impact of contrasting obesity scenarios on TKR burden.

Methods

De-identified TKR and THR data for 2003–2013 were obtained from the Australian Orthopaedic Association National Joint Replacement Registry. Population projections and obesity trends were obtained from the Australian Bureau of Statistics, with public and private hospital costs sourced from the National Hospital Cost Data Collection. Procedure rates were projected according to two scenarios: (1) constant rate of surgery from 2013 onwards; and (2) continued growth in surgery rates based on 2003–2013 growth. Sensitivity analyses were used to estimate future TKR burden if: (1) obesity rates continued to increase linearly; or (2) 1–5% of the overweight or obese population attained a normal body mass index.

Results

Based on recent growth, the incidence of TKR and THR for OA is estimated to rise by 276% and 208%, respectively, by 2030. The total cost to the healthcare system would be $AUD5.32 billion, of which $AUD3.54 billion relates to the private sector. Projected growth in obesity rates would result in 24,707 additional TKRs totalling $AUD521 million. A population-level reduction in obesity could result in up to 8062 fewer procedures and cost savings of up to $AUD170 million.

Conclusions

If surgery trends for OA continue, Australia faces an unsustainable joint replacement burden by 2030, with significant healthcare budget and health workforce implications. Strategies to reduce national obesity could produce important TKR savings.

Electronic supplementary material

The online version of this article (10.1186/s12891-019-2411-9) contains supplementary material, which is available to authorized users.

Associations between Alternate Healthy Eating Index-2010, Body Composition, Osteoarthritis Severity, and Interleukin-6 in Older Overweight and Obese African American Females with Self-Reported Osteoarthritis

Osteoarthritis (OA) is a leading cause of immobility in the United States and is associated with older age, inflammation, and obesity. Prudent dietary patterns have been associated with disease prevention, yet little evidence exists describing diet quality (DQ) in older overweight or obese African American (AA) adults with OA and its relation to body composition. We conducted a secondary data analysis of a dataset containing alternate Healthy Eating Index-2010 (AHEI-2010), body composition, OA severity, and serum interleukin-6 (IL-6) data from 126 AA females (aged 60–87 years) with OA to examine the relationships between these variables. Our sample had poor DQ and reported having higher OA severity as measured by the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC). Interleukin-6 was negatively correlated with AHEI-2010, and AHEI-2010 and the WOMAC physical function subcategory (WOMACpf) were significant predictors of IL-6 (odds ratio (OR): 0.95, 95% confidence interval (CI) 0.92–0.99 and 1.04, 95% CI 1.01–1.07, respectively, p < 0.05) but not body composition. In conclusion, AHEI-2010 and WOMACpf were significant predictors of inflammation (IL-6) and AHEI-2010 accounted for ~16% of the variation of IL-6 (inflammation) in this sample.

Lower extremity osteoarthritis: optimising musculoskeletal health is a growing global concern: a narrative review

The burden of non-communicable diseases, such as osteoarthritis (OA), continues to increase for individuals and society. Regrettably, in many instances, healthcare professionals fail to manage OA optimally. There is growing disparity between the strength of evidence supporting interventions for OA and the frequency of their use in practice. Physical activity and exercise, weight management and education are key management components supported by evidence yet lack appropriate implementation. Furthermore, a recognition that treatment earlier in the disease process may halt progression or reverse structural changes has not been translated into clinical practice. We have largely failed to put pathways and procedures in place that promote a proactive approach to facilitate better outcomes in OA. This paper aims to highlight areas of evidence-based practical management that could improve patient outcomes if used more effectively.

Improving access to better care for people with knee and/or hip pain: service evaluation of allied health professional-led primary care

INTRODUCTION

Chronic knee and hip pain is prevalent, impairing mobility, function and quality of life. Allied health professions (AHPs) are better trained and have more time than general practitioners in primary care to advise and support people to adopt healthier lifestyles (maintain healthy weight, increase physical activity) that reduce joint pain. We evaluated whether AHP-led primary care delivering person-centred, practical lifestyle coaching was a feasible, effective way to manage chronic knee and/or hip pain.

METHODS

At initial assessment the 'Joint Pain Advisor' assessed pain, function, quality of life, physical activity, waist circumference and body mass, taught simple self-management strategies and used behaviour change techniques (motivational interviewing, goal setting, action/coping planning) to alter participants' lifestyles. Participants were invited for 6-week and 6-month reviews, when the Advisor reassessed clinical outcomes, fed back progress and reinforced health messages. Feasibility and effectiveness of the service was evaluated using quantitative and qualitative methods.

RESULTS

Uptake of the service was good: 498 people used the service. Between initial assessment and reviews, participants' pain, function, quality of life, weight, waist circumference and physical activity improved (p < 0.005). Service user satisfaction was high; they reported easier access to advice and support tailored to their needs that translated into clinical benefits and a more efficient pathway reducing unnecessary consultations and investigations. Relatively few people returned for a 6-month review as they considered they had received sufficient advice.

CONCLUSIONS

AHP-led care is a popular, effective, efficient and sustainable way to manage joint pain, without compromising safety or quality of care.

Effect of Obesity on Total Knee Arthroplasty Costs and Revision Rate

An increasing number of total knee arthroplasties (TKAs) are performed on obese patients. It is imperative to remain up to date on the effect of obesity on surgical outcomes and reimbursement trends. The purpose of this study was to evaluate the impact different severities of obesity have on primary and revision TKA, specifically: (1) incidence and trends over time; (2) annual growth rate; and (3) admission costs from 2010 to 2014. A retrospective review of a large commercial private payer database within the PearlDiver Supercomputer application (Warsaw, IN) of TKA procedures was conducted. Patients who underwent TKA and subsequent revision were identified by Current Procedural Terminology (CPT) and ninth revision International Classification of Disease (ICD-9) codes. The index procedure was linked with ICD-9 codes for body mass indexes (BMIs) from <19 to >70. Statistical analysis was primarily descriptive to demonstrate the revision incidence and reimbursement deviations due to BMI. Compound annual growth rate (CAGR) was also calculated. Our query returned a total of 87,607 TKA patients within the study BMI ranges. The majority of patients had a BMI of 40 to 44.9 (12.2%) and least in the BMI >70 (0.2%) range. BMI of 40 to 44.9 had the highest overall 5-year mean reimbursement of $11,521 and the highest overall mean 5-year deviation from normal BMI (19-24) patients of $3,300. The incidence and burden of TKA revision was highest in patients with a BMI of 60 to 69.9 (21 and 17.3%, respectively). Average 5-year revision reimbursement and deviation from normal BMI (19-24) was highest in patients with a BMI of 40 to 44.9 ($13,883 and $4,030, respectively). The number of obese patients receiving TKA is steadily rising. The cost of treating obese patients rises as BMI deviates from normal, as does the incidence of revision surgery. Therefore, surgeons must be active in counseling patients on weight optimization as part of preoperative standard of care.

A Fresh Perspective on a Familiar Problem: Examining Disparities in Knee Osteoarthritis Using a Markov Model

Supplemental Digital Content is available in the text.

Background:

Disparities in the presentation of knee osteoarthritis (OA) and in the utilization of treatment across sex, racial, and ethnic groups in the United States are well documented.

Objectives:

We used a Markov model to calculate lifetime costs of knee OA treatment. We then used the model results to compute costs of disparities in treatment by race, ethnicity, sex, and socioeconomic status.

Research Design:

We used the literature to construct a Markov Model of knee OA and publicly available data to create the model parameters and patient populations of interest. An expert panel of physicians, who treated a large number of patients with knee OA, constructed treatment pathways. Direct costs were based on the literature and indirect costs were derived from the Medical Expenditure Panel Survey.

Results:

We found that failing to obtain effective treatment increased costs and limited benefits for all groups. Delaying treatment imposed a greater cost across all groups and decreased benefits. Lost income because of lower labor market productivity comprised a substantial proportion of the lifetime costs of knee OA. Population simulations demonstrated that as the diversity of the US population increases, the societal costs of racial and ethnic disparities in treatment utilization for knee OA will increase.

Conclusions:

Our results show that disparities in treatment of knee OA are costly. All stakeholders involved in treatment decisions for knee OA patients should consider costs associated with delaying and forgoing treatment, especially for disadvantaged populations. Such decisions may lead to higher costs and worse health outcomes.

Gout and risk of knee replacement for severe knee osteoarthritis in the Singapore Chinese Health Study

OBJECTIVE

While cross-sectional and retrospective case-control studies suggest that gout is associated with knee osteoarthritis (KOA), no prospective study has evaluated the risk of total knee replacement (TKR) for KOA in association with gout. We prospectively evaluated the association between gout and the risk of TKR due to severe KOA.

DESIGN

We used data from the Singapore Chinese Health Study (SCHS), a prospective cohort with 63,257 Chinese adults aged 45-74 years at recruitment (1993-1998). Self-report of physician-diagnosed gout was enquired at follow-up I interview (1999-2004) from 52,322 subjects. TKR cases for KOA after follow-up I were identified via linkage with nationwide hospital discharge database through 31 December 2011. Multivariable Cox proportional hazards regression model was applied with adjustment for potential risk factors of KOA.

RESULTS

Among 51,858 subjects (22,180 men and 29,678 women) included in this analysis, after average 9.7 follow-up years, there were 1,435 cases of TKR. Gout was associated with 39% higher risk of TKR in women [hazard ratio (HR) 1.39; 95% confidence interval (CI) 1.08-1.79] but not in men (HR 0.78; 95% CI 0.49-1.23). The positive gout-TKR association in women remained after excluding participants with self-reported history of arthritis (HR 1.57; 95% CI 1.04-2.37). This association was stronger in women who were lean (body mass index [BMI] < 23 kg/m²) (HR 2.17; 95% CI 1.30-3.64) compared to their heavier counterparts (P_interaction = 0.016).

CONCLUSION

Gout is associated with risk of severe KOA, especially in lean women, suggesting the crystal arthritis may play a role in the pathogenesis or progression of OA.

Knee Biomechanics During Jogging After Arthroscopic Partial Meniscectomy: A Longitudinal Study

BACKGROUND

Altered knee joint biomechanics is thought to play a role in the pathogenesis of knee osteoarthritis and has been reported in patients after arthroscopic partial meniscectomy (APM) while performing various activities. Longitudinally, understanding knee joint biomechanics during jogging may assist future studies to assess the implications of jogging on knee joint health in this population.

PURPOSE

To investigate knee joint biomechanics during jogging in patients 3 months after APM and a healthy control group at baseline and 2 years later at follow-up.

STUDY DESIGN

Controlled laboratory study.

METHODS

Seventy-eight patients who underwent medial APM and 38 healthy controls underwent a 3-dimensional motion analysis during barefoot overground jogging at baseline. Sixty-four patients who underwent APM and 23 controls returned at follow-up. External peak moments (flexion and adduction) and the peak knee flexion angle during stance were evaluated for the APM leg, non-APM leg (nonoperated leg), and control leg.

RESULTS

At baseline, the peak knee flexion angle was 1.4° lower in the APM leg compared with the non-APM leg ( P = .03). No differences were found between the moments in the APM leg compared with the control leg (all P > .05). However, the normalized peak knee adduction moment was 35% higher in the non-APM leg compared with the control leg ( P = .008). In the non-APM leg, the normalized peak knee adduction and flexion moments were higher compared with the APM leg by 16% and 10%, respectively, at baseline ( P ≤ .004). Despite the increase in the peak knee flexion moment in the APM leg compared with the non-APM leg ( P < .001), there were no differences in the peak knee flexion moment or any other parameter assessed at 2-year follow-up between the legs ( P > .05).

CONCLUSION

Comparing the APM leg and control leg, no differences in knee joint biomechanics during jogging for the variables assessed were observed. Higher knee moments in the non-APM leg may have clinical implications for the noninvolved leg. Kinematic differences were small (~1.4°) and therefore of questionable clinical relevance.

CLINICAL RELEVANCE

These results may facilitate future clinical research regarding the implications of jogging on knee joint health in middle-aged, overweight patients after APM.

Serum insulin in pathogenesis and treatment of osteoarthritis

Osteoarthritis (OA) is one of the major health problems that's development and progression is obesity-related. We believe that higher levels of insulin may explains this link especially. High levels of insulin in obesity and metabolic syndrome can induce numerous complications. Insulin can increase proliferation of chondrocyte but simultaneously, it prevents their differentiation. Moreover, hyperinsulinemia reduces the circulating level of serum T4 and conversion of T4 to T3, mimicking hypothyroidism, because thyroid hormones are necessary for the maturation of chondrocytes. So maybe decreasing insulin levels, prevents OA progression or improve the treatment process.

Emerging role of metabolic signaling in synovial joint remodeling and osteoarthritis

Obesity and associated metabolic diseases collectively referred to as the metabolic syndrome increase the risk of skeletal and synovial joint diseases, including osteoarthritis (OA). The relationship between obesity and musculoskeletal diseases is complex, involving biomechanical, dietary, genetic, inflammatory, and metabolic factors. Recent findings illustrate how changes in cellular metabolism and metabolic signaling pathways alter skeletal development, remodeling, and homeostasis, especially in response to biomechanical and inflammatory stressors. Consequently, a better understanding of the energy metabolism of diarthrodial joint cells and tissues, including bone, cartilage, and synovium, may lead to new strategies to treat or prevent synovial joint diseases such as OA. This rationale was the basis of a workshop presented at the 2016 Annual ORS Meeting in Orlando, FL on the emerging role of metabolic signaling in synovial joint remodeling and OA. The topics we covered included (i) the relationship between metabolic syndrome and OA in clinical and pre-clinical studies; (ii) the effect of biomechanical loading on chondrocyte metabolism; (iii) the effect of Wnt signaling on osteoblast carbohydrate and amino acid metabolism with respect to bone anabolism; and (iv) the role of AMP-activated protein kinase in chondrocyte energetic and biomechanical stress responses in the context of cartilage injury, aging, and OA. Although challenges exist for measuring in vivo changes in synovial joint tissue metabolism, the findings presented herein provide multiple lines of evidence to support a central role for disrupted cellular energy metabolism in the pathogenesis of OA. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 34:2048-2058, 2016.

An update on primary care management of knee osteoarthritis

Primary care providers often make the initial diagnosis and play an important role in the effective management of knee osteoarthritis. This article reviews new treatment guidelines from the American Academy of Orthopedic Surgeons and discusses when to refer patients to specialists.

A Meta-Analysis Comparing All-Polyethylene Tibial Component to Metal-Backed Tibial Component in Total Knee Arthroplasty: Assessing Survivorship and Functional Outcomes

BACKGROUND

This meta-analysis compares the clinical performance of all-polyethylene tibial (APT) to the metal-backed tibial (MBT) components.

METHODS

We included comparative studies in primary total knee arthroplasty involving APT and MBT implant components. The primary outcomes were function, durability, and reports of adverse events.

RESULTS

Twenty-eight articles with 95 847 knees were available for synthesis. The meta-analysis showed an association of APT with lower revision rates (incidence rate ratio, 0.709; P = .002) and adverse events (incidence rate ratio, 0.785; P = .204). Moderator analyses were performed to determine the effect of posterior cruciate ligament status on outcome, and no statistically significant effect was found for revision risk or adverse events incidence.

CONCLUSION

All-polyethylene tibial components seem to be an equal option, with less financial burden than the MBT.

Association of urinary metabolites with radiographic progression of knee osteoarthritis in overweight and obese adults: an exploratory study

INTRODUCTION

Metabolic factors may contribute to osteoarthritis (OA). This study employed metabolomics analyses to determine if differences in metabolite profiles could distinguish people with knee OA who exhibited radiographic progression.

METHODS

Urine samples obtained at baseline and 18 months from overweight and obese adults in the Intensive Diet and Exercise for Arthritis (IDEA) trial were selected from two subgroups (n = 22 each) for metabolomics analysis: a group that exhibited radiographic progression (≥0.7 mm decrease in joint space width, JSW) and an age, gender, and body mass index (BMI) matched group who did not progress (≤0.35 mm decrease in JSW). Multivariate analysis methods, including orthogonal partial least square discriminate analysis, were used to identify metabolite profiles that separated progressors and non-progressors. Plasma levels of IL-6 and C-reactive protein (CRP) were evaluated as inflammatory markers.

RESULTS

Multivariate analysis of the binned metabolomics data distinguished progressors from non-progressors. Library matching revealed that glycolate, hippurate, and trigonelline were among the important metabolites for distinguishing progressors from non-progressors at baseline whereas alanine, N,N-dimethylglycine, glycolate, hippurate, histidine, and trigonelline, were among the metabolites that were important for the discrimination at 18 months. In non-progressors, IL-6 decreased from baseline to 18 months while IL-6 was unchanged in progressors; the change over time in IL-6 was significantly different between groups.

CONCLUSION

These findings support a role for metabolic factors in the progression of knee OA and suggest that measurement of metabolites could be useful to predict progression. Further investigation in a larger sample that would include targeted investigation of specific metabolites is warranted.

Effects of Reductions in Body Mass Index on the Future Osteoarthritis Burden in Canada: A Population-Based Microsimulation Study

OBJECTIVE

Osteoarthritis (OA) is the most common joint disease and a major cause of disability. Incidence and prevalence of OA are expected to increase due to population aging and increased levels of obesity. The purpose of this study was to project the effect of hypothetical interventions that change the distribution of body mass index (BMI) on OA burden in Canada.

METHODS

We used a microsimulation computer model of OA based on the Population Health Model platform. The model used demographic predictions for Canada and population data from an administrative database in British Columbia and national Canadian surveys.

RESULTS

Under the base-case scenario, between 2010 and 2030, OA prevalence is expected to increase from 11.5% to 15.6% in men and 16.3% to 21.1% in women. In scenarios assuming, on average, a 0.3-, 0.5-, or 1-unit drop in BMI per year, OA prevalence in 2030 would reach 14.9%, 14.6%, and 14.2% in men and 20.3%, 19.7%, and 18.5%, in women, respectively. Under these scenarios, the proportion of new cases prevented would be 9.5%, 13.2%, and 16.7%, respectively, in men, and 9.1%, 15.2%, and 25.0% in women. Targeting only those people ages ≥50 years for weight reduction would achieve approximately 70% of the impact of a full population strategy. Targeting only the obese (BMI ≥30) would likely result in a larger benefit for men than women.

CONCLUSION

Due to the aging of the population, OA will remain a major and growing health issue in Canada over the next 2 decades, regardless of the course of the obesity epidemic.

Functional and Therapeutic Indications of Liposuction: Personal Experience and Review of the Literature

Liposuction is the most common cosmetic surgical procedure worldwide. It has evolved from being designed primarily for body contouring to becoming essential adjunct to various other aesthetic procedures, greatly enhancing their outcome. Despite its hard clear differentiation between an aesthetic and therapeutic indication for some pathologic conditions, liposuction has been increasingly applied to a gamut of disorders as a therapeutic tool or to improve function. In fact, liposuction has ceased to define a specific procedure and became synonymous to a surgical technique or tool same as the surgical knife, laser, electrocautery, suture material, or even wound-dressing products. At present, there seems to be an enormous potential for the application of the basic liposuction technique in ablative and reconstructive surgery outside the realm of purely aesthetic procedures. The present review contemplates the various nonaesthetic applications of liposuction, displaying the enormous potentials of what should be considered a basic surgical technique rather than a specific aesthetic procedure. Implications of this new definition of liposuction should induce third-party public payers and insurance companies to reconsider their remuneration and reimbursement policies.

Current state of unloading braces for knee osteoarthritis

PURPOSE

Unicompartmental knee osteoarthritis (OA) is often treated with the prescription of an unloading knee brace to decrease pain and stiffness. Braces have been shown to improve the quality of life by applying an external moment to offset increased compressive tibiofemoral contact loads, but evidence regarding mechanical efficacy at the joint is controversial. Thus, the purpose of this study was to review the current state of unloading braces on knee mechanics, clinical impact, and long-term disease progression.

METHODS

A literature search was performed through the PubMed MEDLINE database for the search terms "osteoarthritis," "knee," "brace," and derivatives of the keyword "unload." Articles published since January 1, 1980 were reviewed for their relevance. Evidence for the effectiveness of unloading braces for disease management both biomechanically and clinically was considered.

RESULTS

While significant research has been done to show improvement in OA symptoms with the use of an unloading brace, current literature suggests a debate regarding the effectiveness of these braces for biomechanical change. Clinical findings reveal overall improvements in parameters such as pain, instability, and quality of life.

CONCLUSION

Although clinical evidence supports brace use to improve pain and functional ability, current biomechanical evidence suggests that unloading of the affected knee compartment does not significantly hinder disease progression.

LEVEL OF EVIDENCE

III.

Beer and wine consumption and risk of knee or hip osteoarthritis: a case control study

Introduction

The aim of this study was to investigate the association between alcoholic and non-alcoholic beverages and knee or hip osteoarthritis (OA).

Methods

We conducted a case–control study of Caucasian men and women aged 45 to 86 years of age from Nottingham, UK. Cases had clinically severe symptoms and radiographic knee or hip OA; controls had no symptoms and no radiographic knee or hip OA. Exposure information was sought using interview-based questionnaires and a semi-quantitative food frequency questionnaire to assess beverage consumption at ages 21 to 50 years. Odds ratios (ORs), adjusted ORs (aORs), 95% confidence intervals (CI) and P values were estimated using logistic regression models.

Results

A total of 1,001 knee OA, 993 hip OA and 933 control participants were included in the study. Increasing beer consumption was associated with an increasing risk of OA (P for trend ≤0.001). Compared to those who did not consume beer, aORs for people who consumed 20 or more servings of beer were 1.93 (95% CI 1.26 to 2.94) and 2.15 (95% CI 1.45 to 3.19) for knee OA and hip OA, respectively. In contrast, increasing levels of wine consumption were associated with decreased likelihood of knee OA (P for trend <0.001). Compared to those who did not consume wine, aOR for knee OA among those who consumed 4 to 6 glasses of wine per week and ≥7 glasses of wine per week was 0.55 (95% CI 0.34 to 0.87) and 0.48 (95% CI 0.29 to 0.80), respectively. No association was identified between non-alcoholic beverages and knee or hip OA.

Conclusions

Beer consumption appears to be a risk factor for knee and hip OA whereas consumption of wine has a negative association with knee OA. The mechanism behind these findings is speculative but warrants further study.

Electronic supplementary material

The online version of this article (doi:10.1186/s13075-015-0534-4) contains supplementary material, which is available to authorized users.

Association between body mass index and risk of total knee replacement, the Singapore Chinese Health Study

PURPOSE

Data on the association between body mass index (BMI) and risk of knee osteoarthritis (KOA) are sparse for Asian populations who are leaner than Western populations. We evaluated the association between BMI and risk of total knee replacement (TKR) due to severe KOA among Chinese in Singapore.

METHODS

We used data from the Singapore Chinese Health Study (SCHS), a population-based prospective cohort of 63,257 Chinese men and women, aged 45-74 years at enrollment from 1993 to 1998. Information on height, weight, diet and lifestyle factors were obtained via in-person interviews. TKR cases for severe KOA were identified via linkage with the nationwide hospital discharge database through 2011. Cox regression and weighted least squares regression were used in the analysis.

RESULTS

The mean BMI among cohort participants was 23.1 kg/m(2), and more than two-thirds had BMI below 25 kg/m(2). A total of 1649 had TKR attributable to severe KOA. Risk of TKR increased in a strong dose-dependent manner with increasing BMI throughout the 15-32 kg/m(2) range and became less clear at BMI >32 kg/m(2). In the BMI range 16-27 kg/m(2), there was a 27% increase in TKR risk for each unit increase in BMI (P for trend < 0.001). Compared to BMI 19-20 kg/m(2), the risk estimates of TKR were all statistically significant with increasing unit of BMI ≥21 kg/m(2). Results were similar for men and women.

CONCLUSION

Our results provided evidence for a constant mechanical mechanism underlying BMI and KOA initiation and/or progression.

Body mass index and knee osteoarthritis risk: a dose-response meta-analysis

OBJECTIVE

Evidence shows obesity is an important risk factor for knee osteoarthritis (OA). However, the dose-response relationship between body mass index (BMI) and knee OA risk is unclear. The purpose of the current study is to establish a nonlinear dose-response relationship between BMI and risk of knee OA.

METHODS

The electronic database of PubMed, Web of Science, and translating research into practice (TRIP) database were searched. Observational studies for BMI and knee OA risk were included. Restricted cubic splines and generalized least-squares regression methods were used to model a potential curvilinear relationship and to make a dose-response meta-analysis.

RESULTS

A total of 12 studies were included in the meta-analysis. A non-linear dose-response association between BMI and risk of knee OA was significant (P = 0.001). The relative risks were 1.59 (95% CI: 1.34-1.81), 3.55 (95% CI: 2.51-5.11), and 7.45 (95% CI: 4.19-13.13) when BMI was at the point of 25, 30, and 35 kg/m(2) compared with reference (22.5 kg/m(2) , the median value of the lowest category), respectively. Non-linear dose-response association was also significant in male and female subgroup. In male subgroup, the relative risks were 1.39 (95% CI: 0.99-1.92), 3.41 (95% CI: 2.07-5.48), and 5.71 (95% CI: 3.12-9.95) when BMI was at the point of 25, 30, and 32.5 kg/m(2) compared with reference, respectively. In female subgroup, the relative risks were 1.72 (95% CI: 1.51-1.99), 3.51 (95% CI: 2.65-4.51), and 4.72 (95% CI: 3.25-6.91) compared with reference when BMI was at the point of 25, 30, and 32.5 kg/m(2) compared with reference, respectively. Modest publication bias was found in the meta-analysis. However, sensitivity analysis showed a high stability for the result.

CONCLUSIONS

The meta-analysis indicated that knee OA risk increased almost exponentially according with the increase of body mass index. Knee OA prevention will benefit from weight control.

Functional imaging in OA: role of imaging in the evaluation of tissue biomechanics

Functional imaging refers broadly to the visualization of organ or tissue physiology using medical image modalities. In load-bearing tissues of the body, including articular cartilage lining the bony ends of joints, changes in strain, stress, and material properties occur in osteoarthritis (OA), providing an opportunity to probe tissue function through the progression of the disease. Here, biomechanical measures in cartilage and related joint tissues are discussed as key imaging biomarkers in the evaluation of OA. Emphasis will be placed on the (1) potential of radiography, ultrasound, and magnetic resonance imaging to assess early tissue pathomechanics in OA, (2) relative utility of kinematic, structural, morphological, and biomechanical measures as functional imaging biomarkers, and (3) improved diagnostic specificity through the combination of multiple imaging biomarkers with unique contrasts, including elastography and quantitative assessments of tissue biochemistry. In comparison to other modalities, magnetic resonance imaging provides an extensive range of functional measures at the tissue level, with conventional and emerging techniques available to potentially to assess the spectrum of preclinical to advance OA.

Associations between vitamin D receptor gene polymorphisms and osteoarthritis: an updated meta-analysis

OBJECTIVE

Vitamin D receptor (VDR) gene polymorphisms may be associated with the risk of OA, however, evidence for this is controversial. This meta-analysis aims to confirm whether VDR gene polymorphisms are associated with OA.

METHODS

Meta-analyses on the association between OA and VDR ApaI, BsmI, TaqI and FokI polymorphisms were conducted using allele and homozygote contrast and contrasts in the recessive and dominant models. Stratification analyses by different demographic regions (Europe vs Asian) were also performed and pooled odds ratios (ORs) were obtained using the random effects model if the results were heterogeneous.

RESULTS

A total of 13 relevant studies involving OA patients (n = 2104) and controls (n = 2939) were included in the analysis. There were significant associations between VDR ApaI polymorphisms and OA in the Asian population (A vs a: OR= 1.16, 95% CI 1.02, 1.32, P = 0.025; AA vs Aa/aa: OR= 1.36, 95% CI 1.04, 1.77, P = 0.025; AA vs aa: OR= 1.35, 95% CI 1.00, 1.80, P = 0.047), but not in the whole population. There was also a statistically significant association between FokI polymorphism and OA (FF vs Ff/ff: OR= 0.65, 95% CI 0.44, 0.95, P = 0.024); however, this result was derived from only two studies. No significant associations were found between VDR TaqI and BsmI polymorphisms and OA.

CONCLUSION

There are modest but statistically significant associations between VDR ApaI polymorphisms and the susceptibility of OA in the Asian population.

Determinants of MSK health and disability: lifestyle determinants of symptomatic osteoarthritis

It is frequently considered that, for many people, symptomatic osteoarthritis involving the lower limb joints is a largely preventable 'lifestyle disease'. The purpose of this review is to evaluate the most recent scientific evidence examining the effect of various lifestyle factors, such as physical activity, obesity, diet, smoking, alcohol and injury, on the development of symptomatic knee or hip osteoarthritis. The strengths and weaknesses of various studies are discussed, the magnitude of any demonstrated risks presented and current overall conclusions drawn.

Pharmacologic regimens for knee osteoarthritis prevention: can they be cost-effective?

OBJECTIVE

We sought to determine the target populations and drug efficacy, toxicity, cost, and initiation age thresholds under which a pharmacologic regimen for knee osteoarthritis (OA) prevention could be cost-effective.

DESIGN

We used the Osteoarthritis Policy (OAPol) Model, a validated state-transition simulation model of knee OA, to evaluate the cost-effectiveness of using disease-modifying OA drugs (DMOADs) as prophylaxis for the disease. We assessed four cohorts at varying risk for developing OA: (1) no risk factors, (2) obese, (3) history of knee injury, and (4) high-risk (obese with history of knee injury). The base case DMOAD was initiated at age 50 with 40% efficacy in the first year, 5% failure per subsequent year, 0.22% major toxicity, and annual cost of $1,000. Outcomes included costs, quality-adjusted life expectancy (QALE), and incremental cost-effectiveness ratios (ICERs). Key parameters were varied in sensitivity analyses.

RESULTS

For the high-risk cohort, base case prophylaxis increased quality-adjusted life-years (QALYs) by 0.04 and lifetime costs by $4,600, and produced an ICER of $118,000 per QALY gained. ICERs >$150,000/QALY were observed when comparing the base case DMOAD to the standard of care in the knee injury only cohort; for the obese only and no risk factors cohorts, the base case DMOAD was less cost-effective than the standard of care. Regimens priced at $3,000 per year and higher demonstrated ICERs above cost-effectiveness thresholds consistent with current US standards.

CONCLUSIONS

The cost-effectiveness of DMOADs for OA prevention for persons at high risk for incident OA may be comparable to other accepted preventive therapies.

Lower impulsive loadings following intensive weight loss after bariatric surgery in level and stair walking: a preliminary study

BACKGROUND

There are currently very few of studies which have evaluated the role of bariatric surgery in joint loadings and changes in gait. We wanted to examine how impulsive loading would change level and stair walking in severely or morbidly obese subjects after they had undergone bariatric surgery and weight loss.

METHODS

Thirteen female and three male adults aged between 30 and 63 years, cleared for Roux-en-Y gastric bypass, were recruited into this study. All subjects were severely or morbidly obese i.e., body mass index was >35 kg/m(2). The measurement methods consisted of triaxial skin mounted accelerometers and ground reaction force (GRF); conducted at two different predetermined gait speeds.

RESULTS

The average weight loss was 27.4 (SD8.7) kg after 8.8 (SD3.9) months of follow-up period. Most of the absolute GRF parameters decreased in proportion to weight loss. However, medio-lateral GRF parameters decreased more than expected. The general trend in the knee accelerations demonstrated lower impulsive loadings in both axial and horizontal directions after weight loss. We did not observe any significant changes in stair walking.

CONCLUSIONS

Weight loss after bariatric surgery not only induces a simple mass-related adaptation in gait but also achieves mechanical plasticity in gait strategy.