Individual risk factors for hip osteoarthritis: obesity, hip injury, and physical activity

Selection of a surgical approach for total hip arthroplasty according to the depth to the surgical site

BACKGROUND

The surgical depths of approaches for total hip arthroplasty (THA) have not been reported previously. In this study, we investigate the relationships between the distances to the centre of the femoral head in different approaches and body mass index (BMI).

METHODS

The study included patients with normal hip joints who presented to our hospital. We used the pelvic coordinate system relative to the anterior pelvic plane and the femur coordinate system relative to the posterior condylar plane. We assessed the anterior, anterolateral, lateral and posterior approaches, and defined each approach line. We evaluated each distance in terms of BMI and gender.

RESULTS

164 hips were assessed. The distance to the centre of the femoral head was the longest in the posterior approach, followed by the lateral, anterolateral, and anterior approaches (p<0.05). Additionally, the distance in each approach increased as patients' BMI increased. The approximated line tilts were almost the same. The correlation coefficients between BMI and the distance to the centre of the femoral head were high in all approaches. In the anterior and anterolateral approaches, men with low BMI had a short distance to the femoral head. The distance for each approach was measured according to the pelvic coordinate system and the femur coordinate system. The results showed no significant differences between them.

CONCLUSIONS

The distance to the centre of the femoral head is the shortest in the anterior approach, regardless of BMI and gender. The distance in each approach might increase with an increase in BMI. BMI has similar effects in all approaches.

Adipokine Contribution to the Pathogenesis of Osteoarthritis

Recent studies have shown that overweight and obesity play an important role in the development of osteoarthritis (OA). However, joint overload is not the only risk factor in this disease. For instance, the presence of OA in non-weight-bearing joints such as the hand suggests that metabolic factors may also contribute to its pathogenesis. Recently, white adipose tissue (WAT) has been recognized not only as an energy reservoir but also as an important secretory organ of adipokines. In this regard, adipokines have been closely associated with obesity and also play an important role in bone and cartilage homeostasis. Furthermore, drugs such as rosuvastatin or rosiglitazone have demonstrated chondroprotective and anti-inflammatory effects in cartilage explants from patients with OA. Thus, it seems that adipokines are important factors linking obesity, adiposity, and inflammation in OA. In this review, we are focused on establishing the physiological mechanisms of adipokines on cartilage homeostasis and evaluating their role in the pathophysiology of OA based on evidence derived from experimental research as well as from clinical-epidemiological studies.

Objective functional results in patients with knee osteoarthritis submitted to a 2-day educational programme: a prospective randomised clinical trial

BACKGROUND

Although education is recommended for the treatment of knee osteoarthritis (KOA), its effectiveness in osteoarthritis (OA) remains low according to subjective questionnaires. The timed-up-and-go (TUG) and five-times-sit-to-stand tests (FTSST) reflect muscle strength and balance and could be used as objective measures of effectiveness.

AIM

To measure the effect of an educational programme in patients with KOA by TUG and FTSST and correlate these results to those of subjective questionnaires.

METHODS

Prospective randomised controlled trial of patients with KOA. Participants (n=198) were allocated into four groups. Three groups participated in 2 days of lectures with 1 (group 1), 2 (group 2) and 3-month (group 3) intervals between classes. Group 4 had no classes. Participants were asked to exercise at least three times a week. Half of the patients from all groups received bimonthly telephone calls reinforcing diet and exercise instructions. All four groups received the printed and video material presented in the classes. At baseline and at 1 year after initial assessment, patients performed the FTSST and TUG and answered WOMAC, Lequesne, SF-36 and Visual Analogue Scale questionnaires.

RESULTS

The TUG results did not change at 1 year follow-up, whereas FTSST improved (average difference of 4.66, p<0.001) irrespective of the implementation of classes or telephone calls. Both baseline and 1 year TUG and FTSST results correlated weakly (r<0.3) to the subjective functional, pain and quality of life results (p<0.001).

CONCLUSIONS

This educational programme improved function as determined by lower limb muscle strength (FTSST) irrespective of the patients' subjective non-improvement.

TRIAL REGISTRATION NUMBER

Clinical trials registration number: NCT01572051.

LEVEL OF EVIDENCE

Level 1A.

Factors associated with functional limitations in the daily living activities of Japanese hip osteoarthritis patients

AIM

As society ages, there is a vast number of elderly people with locomotive syndrome. In this study, the factors associated with functional limitations in daily living activities evaluated by female hip osteoarthritis (OA) patients were investigated.

METHODS

This study was a cross-sectional study. The subjects were 353 female patients who were newly diagnosed with hip OA at an orthopedic clinic with no history of hip joint surgery. Outcome indices were functional limitations in two daily living activities obtained from a questionnaire completed by the patients: (i) standing up (standing from a crouched position) and (ii) stair-climbing (climbing and/or descending stairs). The odds ratios (ORs) and 95% confidence intervals (CIs) were computed for explanatory variables using the proportional odds model in logistic regression to evaluate their associations with functional limitations.

RESULTS

Functional limitations in standing up were associated with heavy weight (third tertile vs. first tertile: 1.91, 1.11-3.27), participation in sports at school (0.62, 0.40-0.98), parity (vs. nullipara: 1.96, 1.08-3.56), old age and OA stage. Associations with functional limitations in stair-climbing were seen with short height (< 151.0 cm vs. ≥ 156.0 cm: 2.05, 1.02-4.12), bilateral involvement (vs. unilateral: 1.71, 1.01-2.88), old age and OA stage.

CONCLUSION

Old age, OA stage, heavy weight, parity, shorter height and bilateral OA were associated with functional limitations in standing up and/or stair-climbing, whereas participation in sports such as club activities in school maintained standing up.

Surgical Risks and Costs of Care are Greater in Patients Who Are Super Obese and Undergoing THA

BACKGROUND

Patients with morbid obesity, defined as a BMI greater than 40 kg/m², and super obesity, defined as a BMI greater than 50 kg/m², increasingly present for total hip replacement. There is disagreement in the literature whether these individuals have greater surgical risks and costs for the episode of care, and the magnitude of those risks and costs. There also is no established threshold for obesity as defined by BMI in identifying increased complications, risks, and costs of care. Until recently, analysis of higher BMI data was limited to small cohorts from hospital-based data banks, based on BMI or height and weight only, often as part of a multivariate analysis. On October 1, 2010 the Centers for Medicare & Medicaid Services added a fifth digit to the BMI data, V85.xx, in the Medicare data bank, which allowed data mining of cases of patients with higher BMI. To our knowledge, our study is the first large retrospective Medicare data mining study, which allows us to examine BMI levels greater than 40 and 50 kg/m² to delineate risks, complications, and costs for these patients.

QUESTIONS/PURPOSES

We sought to quantify (1) the surgical risk, and (2) the costs associated with complications after THA in patients who were morbidly obesity (BMI ≥ 40 kg/m²) or super obese (BMI ≥ 50 kg/m²).

METHODS

This is a retrospective study of patients, using Medicare hospital claims data, who underwent THA. The ICD-9 Clinical Modification (CM) diagnosis code V85.4x was used to identify patients with morbid obesity and with super obesity from October 1, 2010 through December 31, 2014. Patients without any BMI-related diagnosis codes were used as the control group. Twelve complications occurring during the 90 days after THA were analyzed using multivariate Cox models adjusting for patient demographic, comorbidities, and institutional factors. In addition, hospital charges and payments were compared from primary surgery through the subsequent 90 days.

RESULTS

Patients with morbid obesity had increased postoperative complications including prosthetic joint infection (hazard ratio [HR], 3.71; 95% CI, 3.2-4.31; p < 0.001), revision (HR, 1.91; 95% CI, 1.69-2.16; p < 0.001), and wound dehiscence (HR, 3.91; 95% CI, 3.14-4.86; p < 0.001). In addition, patients with morbid obesity had increased risk of deep vein thrombosis (HR, 1.43; 95% CI, 1.14-1.79; p < 0.002), pulmonary embolism (HR, 1.57; 95% CI, 1.25-1.99; p < 0.001), implant failure (HR, 1.48; 95% CI, 1.3-1.68; p < 0.001), acute renal failure (HR, 1.68; 95% CI, 1.56-1.80; p < 0.001), and all-cause readmission (HR, 1.48; 95% CI, 1.40-1.56; p < 0.001). However, death (HR, 0.94 95% CI, 0.73-1.19 p < 0.592), acute myocardial infarction (HR, 0.94; 95% CI, 0.74-1.2 p < 0.631), and dislocation (HR 1.07; 95% CI, 0.85-1.34; p < 0.585) were not different between patients in the control and morbidly obese groups. Super obese patients had an increased risk of infection (HR, 6.48; 95% CI, 4.54-9.25; p < 0.001), wound dehiscence (HR, 9.81; 95% CI, 6.31-15.24; p < 0.001), and readmission (HR, 2.16; 95% CI, 1.84-2.54; p < 0.001) compared with patients with normal BMI. Controlling for patient and institutional factors, each THA had mean total hospital charges of USD 88,419 among patients who were super obese compared with USD 73,827 for the control group, a difference of USD 14,591. Medicare payment for the patients who were super obese also was higher, but only by USD 3631.

CONCLUSIONS

Patients who are super obese are at increased risk for serious complications compared with patients with morbid obesity, whose risks are elevated relative to patients whose BMI is less than 40 kg/m². Costs of care for patients who were super obese, likewise, were increased. We present BMI outcomes to allow an objective basis for patient counseling, risk stratification, maintaining access to orthopaedic surgical care, and maintaining hospital operating margins.

LEVEL OF EVIDENCE

Level III, therapeutic study.

Risk and Cost of 90-Day Complications in Morbidly and Superobese Patients After Total Knee Arthroplasty

BACKGROUND

This study investigated the risk and cost of postoperative complications associated with morbid and super obesity after total knee arthroplasty (TKA).

METHODS

A retrospective cohort study was conducted of patients who underwent TKA using Medicare hospital claims data. The International Classification of Diseases, Ninth Revision, Clinical Modification diagnosis code V85.4x was used to identify morbidly obese patients (body mass index [BMI] ≥40 kg/m(2)) and superobese patients (BMI ≥50 kg/m(2)) in 2011-2013. Patients without any BMI-related diagnosis codes were used as controls. Twelve complications occurred in the 90-day period after TKA were analyzed using multivariate Cox models, adjusting for patient demographic, morbidity, and institutional factors. In addition, hospital charges and payments were compared from primary surgery through subsequent 90 days.

RESULTS

Morbidly obese patients showed a significantly elevated risk in most complications examined, with a 2-fold or higher risk in dislocation and wound dehiscence. In addition, death, periprosthetic joint infection, acute renal failure, and knee revision had significant hazard ratios between 1.5 and 2.0. However, risk of deep vein thrombosis and acute myocardial infarction did not increase for the morbidly obese patients. Superobese patients had significant increase in risk of infection, wound dehiscence, acute renal failures, revisions, death, and readmission compared with patients with BMI 40-49 kg/m(2). Significant dose-response trend was found between the level of BMI and risk for death, dislocation, implant failure, infection, readmission, revision, wound dehiscence, and acute renal failure. Controlling for patient and institutional factors, each TKA had an average total hospital charges of $75,884 among superobese patients, compared to $65,118 for the control group, a difference of $10,767. Medicare payment for the superobese patients was also higher, but only by $2703.

CONCLUSION

Morbidly obese patients pose a significantly higher risk profile than normal-weight patients in a broad range of complications after TKA. Superobese patients add another layer of risk compared with less obese patients and are considerably more expensive to treat by health care systems. Technical difficulties and the high demand on resources present a severe challenge for providing treatment for such patients.

A review of important medical and surgical considerations for obese patients undergoing arthroscopic surgery

Obesity represents a unique challenge in orthopaedic surgery, the impact of which is seen through all phases of injury: in the development of disease, during the operative procedure, and throughout the rehabilitation period. Given the high prevalence of obesity in the United States and around the world, this patient population represents a substantial proportion of patients in need of orthopedic care. The effects of this disease constrain both medical and financial resources. For obese patients undergoing orthopedic procedures, adequate steps must be taken to minimize the risks that occur before, during, and after surgical intervention. This literature review discusses the impact of obesity on arthroscopic procedures, with a focus on procedures involving the shoulder, hip, and knee. The management of obese patients during the perioperative period should address the specific concerns relating to these patients. Obesity is a risk factor for numerous comorbidities, is associated with surgical complications, and is a predictor of poor functional outcomes following arthroscopy. Efforts to minimize the negative impact of obesity on arthroscopic procedures are crucial.

The effects of long-term whole-body vibration and aerobic exercise on body composition and bone mineral density in obese middle-aged women

PURPOSE

The purpose of this study was to determine the effectiveness of whole-body passive vibration exercise and its differences from aerobic exercise on body composition, bone mineral density (BMD) and bone mineral content (BMC).

METHODS

Obese middle-aged women (n=33 out of 45) with 34±3% body fat completed the training protocol. They were randomly assigned into diet (n=9; control group), diet plus whole-body vibration exercise (n=13; vibration group), and diet plus aerobic exercise (n=11; aerobic group) groups and we compared their body composition, BMD, and BMC before and after 9 months of training. There were no significant differences in nutrient intake among groups during the training period.

RESULTS

Relative body fat (%) decreased significantly (p < .05) in all three groups and the exercise groups showed a greater reduction in fat mass than the diet only group. BMD in the whole body, lumbar spine, hip and forearm were not significantly different among the three groups. Total body BMC increased significantly in the vibration group throughout the first 6 months of training.

CONCLUSION

Results suggest that long- term vibration training when used in conjunction with a diet program is as effective as aerobic exercise with a diet program in improving body composition of obese middle-aged women without compromising BMC or BMD. Thus, it can be considered a novel and effective method for reducing body fat.

Professional golfers’ hips: prevalence and predictors of hip pain with clinical and MR examinations

Aims

This study aimed to determine the prevalence of hip pain in professional golfers, comparing the lead (left hip in right-handed golfer) and trail hips, and to establish what player characteristics predicted hip symptoms.

Methods

Male elite professional golf players were invited to complete questionnaires and undergo clinical and MR examinations while attending the Scottish Hydro Challenge 2015. Questionnaires determined player demographics, self-reported hip pain and an International Hip Outcome Tool 12 (iHOT12) score (hip-related quality of life). Clinical examinations determined hip range of motion and the presence of a positive impingement test. MR scans determined the presence of labral pathology and player hip morphology with measures of α angle (cam), acetabular depth (pincer) and femoral neck antetorsion.

Results

A total of 109 (70% of tournament field) of players completed questionnaires, 73 (47%) underwent clinical examination and 55 (35%) underwent MR examination. 19.3% of players reported of hip pain. 11.9% of lead and 9.1% of trail hips were painful (p=0.378), iHOT12 scores were lower in the lead (94.1) compared to the trail hip (95.3) (p=0.007). Stepwise multiple linear regression modelling was able to predict 20.7% of the variance in iHOT12 scores with mean α angles between 12 and 3 o'clock, and increasing age-significant variables (R2=0.207, p<0.001; β=−0.502, p<0.001 and β=−0.399, p=0.031, respectively).

Conclusions

19.3% of male professional golfers reported hip pain. The presence of an increasing α angle and increasing age were significant predictors of reduced hip-related quality of life.

Association between direct and indirect smoking and osteoarthritis prevalence in Koreans: a cross-sectional study

OBJECTIVES

To assess the association between smoking patterns and knee and hip joint osteoarthritis (OA) prevalence in Koreans aged 50 years or older with focus on knee OA.

DESIGN

Cross-sectional study using nationally representative data.

SETTING

Data were collected at portable Health Examination Centres in Korea.

PARTICIPANTS

Data of 9064 participants of the 5th Korean National Health and Nutrition Examination Survey (2010-2012) aged 50 years or older who received knee or hip joint X-rays out of 31,596 total surveyees were analysed.

PRIMARY OUTCOME MEASURES

OA prevalence by smoking behaviour (current smoking, past smoking, indirect smoking and non-smoking).

SECONDARY OUTCOME MEASURES

Estimated risk of OA by smoking amount, period, pack-years and indirect smoking exposure time to assess the association between smoking-related factors and knee OA by calculating ORs and adjusting for covariates in a complex sampling design. A multinomial logistic regression analysis and backward elimination method was used.

RESULTS

OA prevalence in Koreans aged 50 years or older was 13.9%, with prevalence about 3.5 times higher in women (men 5.7%, women 20.1%). ORs for knee and hip joint OA prevalence by smoking behaviour in male indirect-smokers were lower than those in non-smokers in age and sex (OR 0.271; 95% CI 0.088 to 0.828), and selective adjustments (OR 0.314; 95% CI 0.102 to 0.966). All other analyses for smoking behaviour and total OA prevalence, and knee OA prevalence were not significantly different. Associations between smoking amount, period, pack-years and knee OA prevalence were non-significant in ever-smokers. Associations between indirect smoking exposure time and knee OA prevalence were also non-significant.

CONCLUSIONS

This study found that though direct and previous smoking and OA prevalence were not associated, there was a weak relationship between indirect smoking and OA.

Association between hip morphology and prevalence, clinical severity and progression of hip osteoarthritis over 3 years: The knee and hip osteoarthritis long-term assessment cohort results

OBJECTIVE

To assess the effects of variations in hip morphology on prevalence, clinical severity and progression of hip osteoarthritis.

METHODS

From 2007 to 2009, we conducted a study of 242 patients aged between 40 and 75 years with symptomatic lower limb osteoarthritis, as part of a population-based osteoarthritis cohort study in France. Standard radiographs of both hips were obtained at baseline and at three years. The progression of hip osteoarthritis was evaluated according to the radiological Kellgren-Lawrence score (KL) and clinical severity from the scores on a Visual Analogic Scale (VAS) for pain recorded yearly. Five measures were used to describe hip morphology: centre edge angle, acetabular index (AI), vertical centre anterior angle, acetabular depth and neck-shaft angle.

RESULTS

Of the 484 hips studied, 205 (42%) showed osteoarthritis at baseline and 16 (11 right and 5 left) underwent joint replacement during the follow-up. AI was the morphological measure most consistently and strongly associated with radiographic osteoarthritis at baseline (odds-ratio=1.05, 95% CI: 1.01-1.08 per degree of angle change), clinical severity (correlation coefficient with VAS during 3 years=0.15, P=0.004), radiological progression (odds-ratio=1.05, 95% CI: 1.00-1.10 per degree) and joint replacement (hazard ratio=1.18, 95% CI: 1.07-1.29 per degree).

CONCLUSIONS

Acetabular obliquity and especially AI is strongly, and likely causally, associated with the existence, severity and progression of hip osteoarthritis.

Prevalence of radiographic hip osteoarthritis and its association with hip pain in Japanese men and women: the ROAD study

OBJECTIVE

Although hip osteoarthritis (OA) is a major cause of hip pain and disability in elderly people, few epidemiologic studies have been performed. We investigated the prevalence of radiographic hip OA and its association with hip pain in Japanese men and women using a large-scale population of a nationwide cohort study, Research on Osteoarthritis/osteoporosis Against Disability (ROAD).

METHODS

From the baseline survey of the ROAD study, 2975 participants (1043 men and 1932 women), aged 23-94 years (mean 70.2 years), living in urban, mountainous, and coastal communities were analyzed. The radiographic severity at both hips was determined by the Kellgren/Lawrence (K/L) grading system. Radiographic hip OA was defined as K/L ≥ 2, and severe radiographic hip OA as K/L ≥ 3.

RESULTS

The crude prevalence of radiographic hip OA was 18.2% and 14.3% in men and women, respectively, that of severe radiographic hip OA was 1.34% and 2.54%, and that of symptomatic K/L ≥ 2 OA was 0.29% and 0.99%, respectively. The crude prevalence of hip OA, including severe OA, was not age-dependent in men or women. Male sex was a risk factor for radiographic hip OA, whereas female sex was a risk factor for severe radiographic hip OA and hip pain. Compared with K/L = 0/1, hip pain was significantly associated with K/L ≥ 3, but not with K/L = 2.

CONCLUSION

The present cross-sectional study revealed the prevalence of radiographic hip OA and severe hip OA in Japanese men and women. Hip pain was strongly associated with K/L ≥ 3.

The impact of obesity on skeletal muscle strength and structure through adolescence to old age

Obesity is associated with functional limitations in muscle performance and increased likelihood of developing a functional disability such as mobility, strength, postural and dynamic balance limitations. The consensus is that obese individuals, regardless of age, have a greater absolute maximum muscle strength compared to non-obese persons, suggesting that increased adiposity acts as a chronic overload stimulus on the antigravity muscles (e.g., quadriceps and calf), thus increasing muscle size and strength. However, when maximum muscular strength is normalised to body mass, obese individuals appear weaker. This relative weakness may be caused by reduced mobility, neural adaptations and changes in muscle morphology. Discrepancies in the literature remain for maximal strength normalised to muscle mass (muscle quality) and can potentially be explained through accounting for the measurement protocol contributing to muscle strength capacity that need to be explored in more depth such as antagonist muscle co-activation, muscle architecture, a criterion valid measurement of muscle size and an accurate measurement of physical activity levels. Current evidence demonstrating the effect of obesity on muscle quality is limited. These factors not being recorded in some of the existing literature suggest a potential underestimation of muscle force either in terms of absolute force production or relative to muscle mass; thus the true effect of obesity upon skeletal muscle size, structure and function, including any interactions with ageing effects, remains to be elucidated.

Arthroscopy and obesity

Obesity is a major public health issue, as incidence is rising in all developed countries, although the proportion is lower in Europe than in the U.S. Over and above the metabolic consequences and increased risk of diabetes, cardiovascular pathology and certain forms of cancer, the present study focuses on osteoarticular risk, and in particular on pathologies manageable by arthroscopy. It also analyzes results and complications specific to arthroscopy in these indications. Meniscal and ligamentous pathologies of the knee, rotator-cuff pathology in the shoulder and tendon pathology in the elbow were not significantly elevated, although a trend emerged. In contrast, there was significant elevation of Achilles and plantar aponeurosis pathology. In terms of postoperative complications, thromboembolic risk was elevated, but there were not significantly more complications specific to arthroscopy. Finally, subjective results were comparable to those for non-obese patients.

LEVEL OF EVIDENCE

Review.

Association between serum concentration of 25-hydroxyvitamin D and the risk of hip arthroplasty for osteoarthritis: result from a prospective cohort study

OBJECTIVES

There is ongoing debate regarding the optimal serum concentrations of 25-hydroxy-vitamin D for musculoskeletal health, including osteoarthritis (OA). The aim of this prospective cohort study was to determine whether serum 25-hydroxy-vitamin D concentrations were associated with the risk of hip arthroplasty for OA.

DESIGN

This study examined 9135 participants from the Australian Diabetes, Obesity and Lifestyle Study who had serum 25-hydroxy-vitamin D measured in 1999-2000 and were aged ≥40 years at the commencement of arthroplasty data collection. The incidence of hip arthroplasty for OA during 2002-2011 was determined by linking cohort records to the Australian Orthopaedic Association National Joint Replacement Registry.

RESULTS

Over an average 9.1 (standard deviation (SD) 2.7) years of follow-up, 201 hip arthroplasties for OA were identified (males n = 90; females n = 111). In males, a one-standard-deviation increase in 25-hydroxy-vitamin D was associated with a 25% increased incidence (HR 1.25, 95% CI 1.02-1.56), with a dose response relationship evident by quartiles of 25-hydroxy-vitamin D concentration (P for trend 0.04). These results were independent of age, body mass index (BMI), ethnicity, smoking status, physical activity, season of blood collection, latitude, hypertension and diabetes, area level disadvantage or after excluding those with extreme low 25-hydroxy-vitamin D concentrations. No significant association was observed in women (HR 1.10, 95% CI 0.87, 1.39).

CONCLUSIONS

Increasing serum 25-hydroxy-vitamin D concentrations were associated with an increased risk of hip arthroplasty for OA in males, while no significant association was observed in females. The mechanism for the association warrants further investigation.

Can We Identify Patients with High Risk of Osteoarthritis Progression Who Will Respond to Treatment? A Focus on Biomarkers and Frailty

Osteoarthritis (OA), a disease affecting different patient phenotypes, appears as an optimal candidate for personalized healthcare. The aim of the discussions of the European Society for Clinical and Economic Aspects of Osteoporosis and Osteoarthritis (ESCEO) working group was to explore the value of markers of different sources in defining different phenotypes of patients with OA. The ESCEO organized a series of meetings to explore the possibility of identifying patients who would most benefit from treatment for OA, on the basis of recent data and expert opinion. In the first meeting, patient phenotypes were identified according to the number of affected joints, biomechanical factors, and the presence of lesions in the subchondral bone. In the second meeting, summarized in the present article, the working group explored other markers involved in OA. Profiles of patients may be defined according to their level of pain, functional limitation, and presence of coexistent chronic conditions including frailty status. A considerable amount of data suggests that magnetic resonance imaging may also assist in delineating different phenotypes of patients with OA. Among multiple biochemical biomarkers identified, none is sufficiently validated and recognized to identify patients who should be treated. Considerable efforts are also being made to identify genetic and epigenetic factors involved in OA, but results are still limited. The many potential biomarkers that could be used as potential stratifiers are promising, but more research is needed to characterize and qualify the existing biomarkers and to identify new candidates.

Assessing risk factors for early hip osteoarthritis in activity-related hip pain: a Delphi study

OBJECTIVE

Hip pain and injury as a result of activity can lead to the development of early hip osteoarthritis (OA) in susceptible individuals. Our understanding of the factors that increase susceptibility continues to evolve. The ability to clearly identify individuals (and cohorts) with activity-related hip pain who are at risk of early hip OA is currently lacking. The purpose of this study was to gain expert consensus on which key clinical measures might help predict the risk of early hip OA in individuals presenting with activity-related hip pain. The agreed measures would constitute a standardised approach to initial clinical assessment to help identify these individuals.

METHODS

This Dephi study used online surveys to gain concordance of expert opinion in a structured process of 'rounds'. In this study, we asked 'What outcome measures are useful in predicting hip OA in activity-related hip pain?' The Delphi panel consisted of experts from sport and exercise medicine, orthopaedics, rheumatology, physiotherapy and OA research.

RESULTS

The study identified key clinical measures in the history, examination and investigations (plain anteroposterior radiograph and femoroacetabular impingement views) that the panel agreed would be useful in predicting future risk of hip OA when assessing activity-related hip pain. The panel also agreed that certain investigations and tests (eg, MR angiography) did not currently have a role in routine assessment. There was a lack of consensus regarding the role of MRI, patient-reported outcome measures (PROMs) and certain biomechanical and functional assessments.

CONCLUSIONS

We provide a standardised approach to the clinical assessment of patients with activity-related hip pain. Assessment measures rejected by the Delphi panel were newer, more expensive investigations that currently lack evidence. Assessment measures that did not reach consensus include MRI and PROMs. Their role remains ambiguous and would benefit from further research.

Is osteoarthritis a metabolic disorder?

BACKGROUND

Obesity is associated with an increased risk of developing osteoarthritis (OA), even in non-weight bearing joints. High levels of adipose tissue-associated inflammation may explain this association.

SOURCES OF DATA AND AREAS OF DEBATE

Published evidence looking at the associations between components of Metabolic Syndrome (MetS) and knee, hip or hand OA and the higher mortality described with knee OA.

EMERGING POINTS

Development of MetS and OA shares a relationship with adipose tissue-associated inflammation. This review supports this inflammatory pathway being part of the shared mechanism behind obesity as a risk factor for OA and the recently described OA-associated increased mortality.

TIMELY AREAS FOR DEVELOPMENT

In an era of an obesity epidemic, this review identifies a need for well-designed cohort studies assessing early metabolic changes in populations at high risk of OA and MetS, and to identify risk factors for increased mortality in patients with OA.

Lower limb clinical and radiographic osteoarthritis in former elite male athletes

PURPOSE

To investigate the prevalence of lower extremities clinical and radiographic OA in former elite male athletes and referents from the general population and to examine its association with the participants' demographic characteristics.

METHODS

Two hundred and eighteen former elite male athletes (soccer, volleyball, martial arts, track and field and basketball players, and skiers) and 181 male controls that reported no systematic athletic activity were examined by means of questionnaire, clinical and radiographic evaluation. Exclusion criteria were age younger than 40 years and a positive history of lower extremity surgery, bone or soft tissue trauma and inflammatory arthropathy.

RESULTS

Overall, the prevalence of clinical OA between former elite athletes (15.6 %) and controls (14.4 %) was similar (n.s.). The prevalence of radiographic OA was significantly higher (p = 0.03) in former elite athletes (36.6 %) compared with controls (23.9 %). All the participants with clinical OA who underwent radiographic examination also had radiographic OA. The prevalence of clinical and radiographic OA was similar (n.s.) between former athletes of different sports. Age, body mass index (BMI) and occupation variably predicted the prevalence of hip, knee and ankle OA in both study groups.

CONCLUSIONS

In the absence of major bone and soft tissue lower limb trauma during their athletic career, former elite athletes may not be at increased risk of developing clinical OA. Radiographic signs of OA present at a significantly higher incidence and possibly precede the clinical onset of OA. Age, BMI and occupation are identified as strong predictors of the development of OA in former elite athletes.

Socio-economic status and the risk of developing hand, hip or knee osteoarthritis: a region-wide ecological study

OBJECTIVE

To determine the association between socio-economic status (SES) and risk of hand, hip or knee osteoarthritis (OA) at a population level.

DESIGN

Retrospective ecological study using the System for the Development of Research in Primary Care (SIDIAP) database (primary care anonymized records for >5 million people in Catalonia (Spain)). Urban residents >15 years old (2009-2012) were eligible.

OUTCOMES

Validated area-based SES deprivation index MEDEA (proportion of unemployed, temporary workers, manual workers, low educational attainment and low educational attainment among youngsters) was estimated for each area based on census data as well as incident diagnoses (ICD-10 codes) of hand, hip or knee OA (2009-2012). Zero-inflated Poisson models were fitted to study the association between MEDEA quintiles and the outcomes.

RESULTS

Compared to the least deprived, the most deprived areas were younger (43.29 (17.59) vs 46.83 (18.49), years (Mean SD), had fewer women (49.1% vs 54.8%), a higher percentage of obese (16.2% vs 8.4%), smokers (16.9% vs 11.9%) and high-risk alcohol consumption subjects (1.5% vs 1.3%). Compared to the least deprived, the most deprived areas had an excess risk of OA: age-sex-adjusted Incidence Rate Ratio (IRR) 1.26 (1.11-1.42) for hand, 1.23 (1.17-1.29) hip, and 1.51 (1.45-1.57) knee. Adjustment for obesity attenuated this association: 1.06 (0.93-1.20), 1.04 (0.99-1.09), and 1.23 (1.19-1.28) respectively.

CONCLUSIONS

Deprived areas have higher rates OA (hand, hip, knee). Their increased prevalence of obesity accounts for a 50% of the excess risk of knee OA observed. Public health interventions to reduce the prevalence of obesity in this population could reduce health inequalities.

Patient, Surgery, and Hospital Related Risk Factors for Surgical Site Infections following Total Hip Arthroplasty

Surgical site infections (SSI) following total hip arthroplasty (THA) have a significantly adverse impact on patient outcomes and pose a great challenge to the treating surgeon. Therefore, timely recognition of those patients at risk for this complication is very important, as it allows for adopting measures to reduce this risk. This review discusses literature reported risk factors for SSI after THA. These can be classified into patient-related factors (age, gender, obesity, comorbidities, history of infection, primary diagnosis, and socioeconomic profile), surgery-related factors (allogeneic blood transfusion, DVT prophylaxis and coagulopathy, duration of surgery, antibiotic prophylaxis, bearing surface and fixation, bilateral procedures, NNIS index score, and anesthesia type), and hospital-related factors (duration of hospitalization, institution and surgeon volume, and admission from a healthcare facility). All these factors are discussed with respect to potential measures that can be taken to reduce their effect and consequently the overall risk for infection.

Bone geometry of the hip is associated with obesity and early structural damage--a 3.0 T magnetic resonance imaging study of community-based adults

Introduction

The mechanism by which obesity increases the risk of hip osteoarthritis is unclear. One possibility may be by mediating abnormalities in bony geometry, which may in turn be associated with early structural abnormalities, such as cartilage defects and bone marrow lesions.

Methods

One hundred and forty one older adults with no diagnosed hip osteoarthritis had weight and body mass index measured between 1990 and 1994 and again in 2009 to 2010. Acetabular depth and lateral centre edge angle, both measures of acetabular over-coverage, as well as femoral head cartilage volume, cartilage defects and bone marrow lesions were assessed with 3.0 T magnetic resonance imaging performed in 2009 to 2010.

Results

Current body mass index, weight and weight gain were associated with increased acetabular depth and lateral centre edge angle (all P ≤ 0.01). For every 1 mm increase in acetabular depth, femoral head cartilage volume reduced by 59 mm³ (95% confidence interval (CI) 20 mm³ to 98 mm³, P < 0.01). Greater acetabular depth was associated with an increased risk of cartilage defects (odds ratio (OR) 1.22, 95% CI 1.03 to 1.44, P = 0.02) and bone marrow lesions (OR 1.29, 95% CI 1.01 to 1.64, P = 0.04) in the central region of the femoral head. Lateral centre edge angle was not associated with hip structure.

Conclusions

Obesity is associated with acetabular over-coverage. Increased acetabular depth, but not the lateral centre edge angle, is associated with reduced femoral head cartilage volume and an increased risk of cartilage defects and bone marrow lesions. Minimising any deepening of the acetabulum (for example, through weight management) might help to reduce the incidence of hip osteoarthritis.

Early cartilage abnormalities at the hip are associated with obesity and body composition measures - a 3.0T MRI community-based study

Introduction

Although obesity is a risk factor for hip osteoarthritis (OA), the role of body composition, if any, is unclear. This study examines whether the body mass index (BMI) and body composition are associated with hip cartilage changes using magnetic resonance imaging (MRI) in community-based adults.

Methods

141 community-based participants with no clinical hip disease, including OA, had BMI and body composition (fat mass and fat free mass) measured at baseline (1990 to 1994), and BMI measured and 3.0 T MRI performed at follow-up (2009–2010). Femoral head cartilage volume was measured and femoral head cartilage defects were scored in the different hip regions.

Results

For females, baseline BMI (β = −26 mm³, 95% Confidence interval (CI) -47 to −6 mm³, p = 0.01) and fat mass (β = −11 mm³, 95% CI −21 to −1 mm³, p = 0.03) were negatively associated with femoral head cartilage volume. Also, while increased baseline fat mass was associated with an increased risk of cartilage defects in the central superolateral region of the femoral head (Odds Ratio (OR) = 1.08, 95% CI 1.00–1.15, p = 0.04), increased baseline fat free mass was associated with a reduced risk of cartilage defects in this region (OR = 0.82, 95% CI 0.67–0.99; p = 0.04). For males, baseline fat free mass was associated with increased femoral head cartilage volume (β = 40 mm³, 95% CI 6 to 74 mm³, p = 0.02).

Conclusions

Increased fat mass was associated with adverse hip cartilage changes for females, while increased fat free mass was associated with beneficial cartilage changes for both genders. Further work is required to determine whether modifying body composition alters the development of hip OA.

Future projections of total hip and knee arthroplasty in the UK: results from the UK Clinical Practice Research Datalink

OBJECTIVE

To estimate the future rate of primary total hip (THR) or knee (TKR) replacement in the UK to 2035 allowing for changes in population demographics and obesity.

DESIGN

Using age/gender/body mass index (BMI)-specific incidence rates from a population-based cohort study of 50,000 THR and 45,609 TKR patients from the UK Clinical Practice Research Datalink (CPRD) between 1991 and 2010, we projected future numbers of THR and TKR using two models: a static, estimated rate from 2010 applied to population growth forecasts to 2035, and a log-linear rate extrapolation over the same period. Both scenarios used population forecast data from the UK Office for National Statistics (ONS).

RESULTS

Assuming rates of THR and TKR for 2010, and given projected population changes in age, gender and BMI, the number of THRs and TKRs performed in the UK in 2035 is estimated to be, respectively: 95,877 and 118,666. By comparison, an exponential extrapolation of historical rates using a log-linear model produces much higher estimates of THR and TKR counts in 2035 at 439,097 and 1,219,362 respectively. Projected counts were higher for women than men. Assuming a changing (rather than fixed) future BMI distribution increases TKRs by 2035 but not THRs.

CONCLUSIONS

Using historical rates and population forecasts we have projected the number of THR/TKR operations in the UK up to 2035. This study will inform policymakers requiring estimates of future demand for surgery. Incorporating future forecasts for BMI into projections of joint replacement may be more relevant for TKR rather than THR.

Risk factors for osteoarthritis and contributing factors to current arthritic pain in South Korean older adults

PURPOSE

Although previous studies have focused on risk factors for osteoarthritis, there is some debate on this issue. Furthermore, associated factors with arthritic symptom (arthralgia) have not been sufficiently investigated, despite its clinical importance in the management of osteoarthritis. This study was performed to examine the risk factors for osteoarthritis and the contributing factors to current arthritic pain in older adults.

MATERIALS AND METHODS

The Fourth Korean National Health and Nutrition Examination Surveys was conducted in 2009. Therein, 720 males and 1008 females aged 65 years and older were included. Comprehensive data on habitual, socioeconomic, medical, nutritional, and psychological factors were collected along with the presence of osteoarthritis and arthritic pain. After univariate analysis, binary logistic regression analysis was performed to identify risk factors for osteoarthritis and contributing factors to current arthritic pain.

RESULTS

Age (p=0.005), female gender (p<0.001), higher body mass index (BMI) (p<0.001), and osteoporosis (p<0.001) were significant risk factors for osteoarthritis, while higher education level (p=0.025) was a protective factor for osteoarthritis. Higher BMI (p=0.047), lack of weekly moderate intensity activity (p<0.001), and unfavorable subjective health status (p<0.001) were significant factors contributing to current arthritic pain among subjects with osteoarthritis. Both osteoarthritis and current arthritic pain adversely affected health related quality of life.

CONCLUSION

Higher BMI, lack of weekly moderate intensity activity, and unfavorable subjective health status were significant factors contributing to current arthritic pain. More attention needs to be paid to psychiatric effects on osteoarthritis and joint related pain.

Free fatty acids: potential proinflammatory mediators in rheumatic diseases

OBJECTIVES

Due to their role in inflammatory metabolic diseases, we hypothesised that free fatty acids (FFA) are also involved in inflammatory joint diseases. To test this hypothesis, we analysed the effect of FFA on synovial fibroblasts (SF), human chondrocytes and endothelial cells. We also investigated whether the toll-like receptor 4 (TLR4), which can contribute to driving arthritis, is involved in FFA signalling.

METHODS

Rheumatoid arthritis SF, osteoarthritis SF, psoriatic arthritis SF, human chondrocytes and endothelial cells were stimulated in vitro with different FFA. Immunoassays were used to quantify FFA-induced protein secretion. TLR4 signalling was inhibited extracellularly and intracellularly. Fatty acid translocase (CD36), responsible for transporting long-chain FFA into the cell, was also inhibited.

RESULTS

In rheumatoid arthritis synovial fibroblasts (RASF), FFA dose-dependently enhanced the secretion of the proinflammatory cytokine IL-6, the chemokines IL-8 and MCP-1, as well as the matrix-degrading enzymes pro-MMP1 and MMP3. The intensity of the response was mainly dependent on the patient rather than on the type of disease. Both saturated and unsaturated FFA showed similar effects on RASF, while responses to the different FFA varied for human chondrocytes and endothelial cells. Extracellular and intracellular TLR4 inhibition as well as fatty acid transport inhibition blocked the palmitic acid-induced IL-6 secretion of RASF.

CONCLUSIONS

The data show that FFA are not only metabolic substrates but may also directly contribute to articular inflammation and degradation in inflammatory joint diseases. Moreover, the data suggest that, in RASF, FFA exert their effects via TLR4 and require extracellular and intracellular access to the TLR4 receptor complex.

Current and future impact of osteoarthritis on health care: a population-based study with projections to year 2032

OBJECTIVE

To estimate the current and future (to year 2032) impact of osteoarthritis (OA) health care seeking.

METHOD

Population-based study with prospectively ascertained data from the Skåne Healthcare Register (SHR), Sweden, encompassing more than 15 million person-years of primary and specialist outpatient care and hospitalizations. We studied all Skåne region residents aged ≥45 by the end of 2012 (n = 531, 254) and determined the prevalence of doctor-diagnosed OA defined as the proportion of the prevalent population that had received a diagnosis of OA of the knee, hip, hand, or other locations except the spine between 1999 and 2012. We projected consultation prevalence of OA until year 2032 using Statistics Sweden's (SCB) projected age and sex structure and prevalence of overweight and obesity.

RESULTS

In 2012 the proportion of population aged ≥45 with any doctor-diagnosed OA was 26.6% (95% confidence interval (CI): 26.5-26.8) (men 22.4%, women 30.5%). The most common locations were knee (13.8%), hip (5.8%) and hand (3.1%). Of the prevalent cases 26.8% had OA in multiple joints. By the year 2032, the proportion of the population aged ≥45 with doctor-diagnosed OA is estimated to increase from 26.6% to 29.5% (any location), from 13.8% to 15.7% for the knee and 5.8-6.9% for the hip.

CONCLUSION

In 2032, at least an additional 26,000 individuals per 1 million population aged ≥45 years are estimated to have consulted a physician for OA in a peripheral joint compared to 2012. These findings underscore the need to address modifiable risk factors and develop new effective OA treatments.

Defining structural abnormalities of the hip joint at risk of degeneration

The purpose of this review is to explore the mounting evidence that primary osteoarthritis is secondary to childhood disorders such as dysplasia and/or to subtle morphologic and structural to subtle morphologic and structural abnormalities of the proximal femur and/or acetabulum that were previously unrecognized or underestimated. These structural deformities lead to early impingement through range of motion and subsequent joint degeneration. The review also presents a brief synopsis of the genetic components that influence structural morphology of the hip joint and the impact of genetic pathways on OA development. If subtle deformities can be shown to be effective predictors of OA in the general population, it may be possible to identify hips that are at risk before they progress to end-stage OA. Furthermore, if these early risk factors are modifiable, it may be possible to implement preventative measures before the requirement of total hip arthroplasty.

Body mass index and risk of perioperative cardiovascular adverse events and mortality in 34,744 Danish patients undergoing hip or knee replacement

BACKGROUND AND PURPOSE

Obesity is a risk factor for osteoarthritis in the lower limb, yet the cardiovascular risks associated with obesity in hip or knee replacement surgery are unknown. We examined associations between body mass index (BMI) and the risk of a major adverse cardiovascular event (MACE: ischemic stroke, acute myocardial infarction, or cardiovascular death) or the risk of all-cause mortality in a nationwide Danish cohort of patients who underwent primary hip or knee replacement surgery.

METHODS

Using Danish nationwide registries, we identified 34,744 patients aged ≥ 20 years who underwent elective primary hip or knee replacement surgery between 2005 and 2011. We used multivariable Cox regression models to calculate the 30-day risks of MACE and mortality associated with 5 BMI groups (underweight (BMI < 18.5 kg/m(2)), normal weight (18.5-24 kg/m(2)), overweight (25-29 kg/m(2)), obese 1 (30-34 kg/m(2)), and obese 2 (≥ 35 kg/m(2))).

RESULTS

In total, 232 patients (0.7%) had a MACE and 111 (0.3%) died. Compared with overweight, adjusted hazard ratios (HRs) were 1.2 (95% CI: 0.4-3.3), 1.3 (0.95-1.8), 1.6 (1.1-2.2), and 1.0 (0.6-1.9) for underweight, normal weight, obese 1, and obese 2 regarding MACE. Regarding mortality, the corresponding HRs were 7.0 (2.8-15), 2.0 (1.2-3.2), 1.5 (0.9-2.7), and 1.9 (0.9-4.2). Cubic splines suggested a significant U-shaped relationship between BMI and risks with nadir around 27-28.

INTERPRETATION

In an unselected cohort of patients undergoing elective primary hip or knee replacement surgery, U-shaped risks of perioperative MACE and mortality were found in relation to BMI. Patients within the extreme ranges of BMI may warrant further attention.

Musculoskeletal Function and Obesity: Implications for Physical Activity

However quantified, obesity is a global health problem of significant magnitude. The condition is no longer limited to the developed world, with an increasing proportion of low-to-middle income countries burdened by obesity and its comorbidities. Specifically, obesity is a risk factor for a raft of psychosocial, physiological, cardiovascular, and metabolic problems. The carriage of excess body weight, including an unhealthy proportion of body fat, also has important implications for musculoskeletal health. To date, this important relationship has not received as much attention by the research community. Coincidentally, there has been a heightened interest in the role of physical activity and exercise across the lifespan in the prevention, treatment and management of obesity. This paper considers some of the more common musculoskeletal problems in children, adolescents and adults with implications for the overweight and obese and their meaningful engagement in physical activity.

A guide to exercise prescription

Exercise is a fundamental component of good health. The American College of Sports Medicine and "Exercise is Medicine" recommend treating exercise as a vital sign, and assessing and prescribing physical activity at every medical visit. Meeting the recommended goals of physical activity results in a significant reduction in all-cause mortality. Physicians can improve health by prescribing exercise.

Toward the interpretation of the combined effect of size and body weight on the tribological performance of total knee prostheses

PURPOSE

The research questions of the present study were: (1) Is total knee prosthesis wear behaviour influenced by implant size, body weight and their combined effect? (2) Are these findings significant and helpful from a clinical point of view?

METHODS

Two very different sizes of the same total knee prosthesis (TKP), previously tested with ISO 14243 parameters, were tested on a knee simulator for a further two million cycles using a modified ISO 14243 load waveform. Roughness examination was performed on the metallic components. Gravimetric and micro-Raman spectroscopic analyses were carried out on the polyethylene inserts.

RESULTS

The average volumetric mass loss was 69 ± 3 mm(3) and 88 ± 4 mm(3) for smaller and bigger size, respectively. Bigger TKPs are little influenced by an increased load, while the wear trend of the smaller TKP showed a redoubled slope, and more significant morphology changes were observed. However, the two sizes seem to behave similarly when subjected to a load increase of 15 %; the slope of the volumetric mass loss trend was comparable for the two sets of inserts, which did not appear significantly different also at the molecular level. Roughness average parameters of the lateral femoral condyle support this evidence.

CONCLUSIONS

It can be asserted that the body weight and implant size are relevant to the understanding of TKP wear behaviour. A post-implantation body weight increase in a patient with smaller knee dimensions could results in more critical effects on prosthesis long-term performance.

Medicinal chemistry of the epigenetic diet and caloric restriction

The pronounced effects of the epigenetic diet (ED) and caloric restriction (CR) have on epigenetic gene regulation have been documented in many pre-clinical and clinical studies. Understanding epigenetics is of high importance because of the concept that external factors such as nutrition and diet may possess the ability to alter gene expression without modifying the DNA sequence. The ED introduces bioactive medicinal chemistry compounds such as sulforaphane (SFN), curcumin (CCM), epigallocatechin gallate (EGCG) and resveratrol (RSV) that are thought to aid in extending the human lifespan. CR, although similar to ED in the target of longevity, mildly reduces the total daily calorie intake while concurrently providing all beneficial nutrients. Both CR and ED may act as epigenetic modifiers to slow the aging process through histone modification, DNA methylation, and by modulating microRNA expression. CR and ED have been proposed as two important mechanisms that modulate and potentially slow the progression of age-related diseases such as cardiovascular disease (CVD), cancer, obesity, Alzheimer's and osteoporosis to name a few. While many investigators have examined CR and ED as separate entities, this review will primarily focus on both as they relate to age-related diseases, their epigenetic effects and their medicinal chemistry.

The Association between a History of Parental Addictions and Arthritis in Adulthood: Findings from a Representative Community Survey

Aims. To examine the relationship between a history of parental addictions and the cumulative lifetime incidence of arthritis while controlling for age, sex, race, and four clusters of risk factors: (1) other adverse childhood experiences, (2) adult health behaviors (i.e., smoking, obesity, inactivity, and alcohol consumption), (3) adult socioeconomic status and (4) mental health. Materials and Methods. Secondary analysis of 13,036 Manitoba and Saskatchewan respondents of the population-based 2005 Canadian Community Health Survey. Sequential logistic regression analyses were conducted. Findings. After controlling for demographic characteristics, including age, gender, and race, respondents who reported a history of parental addictions had significantly higher odds of arthritis in comparison to individuals without (OR=1.58; 95% CI 1.38–1.80). Adjustment for socioeconomic status, adult health behaviors, and mental health conditions had little impact on the parental addictions and arthritis relationship. The association between parental addictions and arthritis was substantially reduced when adverse childhood experiences (OR=1.33; 95% CI 1.15–1.53) and all four groups of risk factors collectively (OR=1.30; 95% CI = 1.12–1.51) were included in the analyses; however, the relationship remained statistically significant. Conclusions. A robust association was found between parental addictions and cumulative lifetime incidence of arthritis. This link remained even when controlling for four groups of potential risk factors.

Effects of obesity on lower extremity muscle function during walking at two speeds

Walking is a recommended form of physical activity for obese adults, yet the effects of obesity and walking speed on the biomechanics of walking are not well understood. The purpose of this study was to examine joint kinematics, muscle force requirements and individual muscle contributions to the walking ground reaction forces (GRFs) at two speeds (1.25 ms(-1) and 1.50 ms(-1)) in obese and nonobese adults. Vasti (VAS), gluteus medius (GMED), gastrocnemius (GAST), and soleus (SOL) forces and their contributions to the GRFs were estimated using three-dimensional musculoskeletal models scaled to the anthropometrics of nine obese (35.0 (3.78 kg m(-2))); body mass index mean (SD)) and 10 nonobese (22.1 (1.02 kg m(-2))) subjects. The obese individuals walked with a straighter knee in early stance at the faster speed and greater pelvic obliquity during single limb support at both speeds. Absolute force requirements were generally greater in obese vs. nonobese adults, the main exception being VAS, which was similar between groups. At both speeds, lean mass (LM) normalized force output for GMED was greater in the obese group. Obese individuals appear to adopt a gait pattern that reduces VAS force output, especially at speeds greater than their preferred walking velocity. Greater relative GMED force requirements in obese individuals may contribute to altered kinematics and increased risk of musculoskeletal injury/pathology. Our results suggest that obese individuals may have relative weakness of the VAS and hip abductor muscles, specifically GMED, which may act to increase their risk of musculoskeletal injury/pathology during walking, and therefore may benefit from targeted muscle strengthening.

Altered mechano-chemical environment in hip articular cartilage: effect of obesity

The production of extracellular matrix (ECM) components of articular cartilage is regulated, among other factors, by an intercellular signaling mechanism mediated by the interaction of cell surface receptors (CSR) with insulin-like growth factor-1 (IGF-1). In ECM, the presence of binding proteins (IGFBP) hinders IGF-1 delivery to CSR. It has been reported that levels of IGF-1 and IGFBP in obese population are, respectively, lower and higher than those found in normal population. In this study, an experimental-numerical approach was adopted to quantify the effect of this metabolic alteration found in obese population on the homeostasis of femoral hip cartilage. A new computational model, based on the mechano-electrochemical mixture theory, was developed to describe competitive binding kinetics of IGF-1 with IGFBP and CSR, and associated glycosaminoglycan (GAG) biosynthesis. Moreover, a gait analysis was carried out on obese and normal subjects to experimentally characterize mechanical loads on hip cartilage during walking. This information was deployed into the model to account for effects of physiologically relevant tissue deformation on GAG production in ECM. Numerical simulations were performed to compare GAG biosynthesis in femoral hip cartilage of normal and obese subjects. Results indicated that the lower ratio of IGF-1 to IGFBP found in obese population reduces cartilage GAG concentration up to 18 % when compared to normal population. Moreover, moderate physical activity, such as walking, has a modest beneficial effect on GAG production. The findings of this study suggest that IGF-1/IGFBP metabolic unbalance should be accounted for when considering the association of obesity with hip osteoarthritis.

Is osteoarthritis a metabolic disease?

Obesity, together with aging and injury, is among the main risk factors for osteoarthritis. Obesity-related osteoarthritis can affect not only the weight-bearing joints, but also the hands, suggesting a role for circulating mediators released by the adipose tissue and known as adipokines. Thus, osteoarthritis may have a systemic metabolic component. Evidence from both epidemiological and biological studies support the concept of metabolic osteoarthritis, defined as a broad clinical phenotype that includes obesity-related osteoarthritis. Thus, osteoarthritis can be related to metabolic syndrome or to an accumulation of metabolic abnormalities. In addition, studies have demonstrated associations linking osteoarthritis to several components of the metabolic syndrome, such as hypertension and type 2 diabetes, independently from obesity or any of the other known risk factors for osteoarthritis. Both in vitro and in vitro findings indicate a deleterious effect of lipid and glucose abnormalities on cartilage homeostasis. Chronic low-grade inflammation is a feature shared by osteoarthritis and metabolic disorders and may contribute to the genesis of both. Thus, osteoarthritis is emerging as a disease that has a variety of phenotypes including a metabolic phenotype, in addition to the age-related and injury-related phenotypes.

Endoprosthesis and obesity

INTRODUCTION

Obesity represents a significant risk factor in the pathophysiology of degenerative changes in coxarthrosis.

OBJECTIVE

The study aims to investigate obesity as a risk factor in the examined sample comprising 136 patients who underwent hip endoprothesis implantation.

MATERIAL AND METHODS

The series comprised 136 patients with a hip endoprosthesis implanted, where the patients' BMI, amount of blood used, duration of surgery, number of assistants, and type of anaesthesia were observed. Wounds and late post-operative complications, infections, haemorrhage, vein thrombosis, endoprosthesis dislocations, length of inpatient stay, start of physical therapy and full weight-bearing were also observed. The observation period lasted six months on average.

DISCUSSION

In simple terms, the three greatest factors when implanting a hip endoprosthesis are as follows: properties of the endoprosthesis, the orthopaedic surgeon's skill and experience, and individual characteristics of the patient, i.e. age, sex, health condition, body weight, BMI, adequate physical therapy.

CONCLUSION

We believe that the implantation of a hip endoprosthesis should be postponed for patients with a BMI exceeding 29.99. Such patients should receive endocrine treatment, they should undergo a weight loss programme in order to reduce their body weight and in order to reduce their BMI to under 29.99.

Methodologies for semiquantitative evaluation of hip osteoarthritis by magnetic resonance imaging: approaches based on the whole organ and focused on active lesions

OBJECTIVE

As a wider variety of therapeutic options for osteoarthritis (OA) becomes available, there is an increasing need to objectively evaluate disease severity on magnetic resonance imaging (MRI). This is more technically challenging at the hip than at the knee, and as a result, few systematic scoring systems exist. The OMERACT (Outcome Measures in Rheumatology) filter of truth, discrimination, and feasibility can be used to validate image-based scoring systems. Our objective was (1) to review the imaging features relevant to the assessment of severity and progression of hip OA; and (2) to review currently used methods to grade these features in existing hip OA scoring systems.

METHODS

A systematic literature review was conducted. MEDLINE keyword search was performed for features of arthropathy (such as hip + bone marrow edema or lesion, synovitis, cyst, effusion, cartilage, etc.) and scoring system (hip + OA + MRI + score or grade), with a secondary manual search for additional references in the retrieved publications.

RESULTS

Findings relevant to the severity of hip OA include imaging markers associated with inflammation (bone marrow lesion, synovitis, effusion), structural damage (cartilage loss, osteophytes, subchondral cysts, labral tears), and predisposing geometric factors (hip dysplasia, femoral-acetabular impingement). Two approaches to the semiquantitative assessment of hip OA are represented by Hip OA MRI Scoring System (HOAMS), a comprehensive whole organ assessment of nearly all findings, and the Hip Inflammation MRI Scoring System (HIMRISS), which selectively scores only active lesions (bone marrow lesion, synovitis/effusion). Validation is presently confined to limited assessment of reliability.

CONCLUSION

Two methods for semiquantitative assessment of hip OA on MRI have been described and validation according to the OMERACT Filter is limited to evaluation of reliability.

A Review on the Management of Hip and Knee Osteoarthritis

Arthritis is the most common chronic condition affecting patients over the age of 70. The prevalence of osteoarthritis increases with age, and with an aging population, the effect of this disease will represent an ever-increasing burden on health care. The knee is the most common joint affected in osteoarthritis, with up to 41% of limb arthritis being located in the knee, compared to 30% in hands and 19% in hips. We review the current concepts with regard to the disease process and risk factors for developing hip and knee osteoarthritis. We then explore the nonsurgical management of osteoarthritis as well as the operative management of hip and knee arthritis. We discuss the indications for surgical treatment of hip and knee arthritis, looking in particular at the controversies affecting young and obese patients in both hip and knee replacements. Patient and implant related outcomes along with survivorships are addressed as well as the experiences and controversies described in national joint registries.

Are joint injury, sport activity, physical activity, obesity, or occupational activities predictors for osteoarthritis? A systematic review

STUDY DESIGN

Systematic review with meta-analysis.

OBJECTIVES

To identify risk factors for osteoarthritis (OA) of the knee, hip, and ankle, including joint injury, sport, physical activity, overweight/obesity, and occupational activity, in all age groups.

BACKGROUND

OA is a significant health problem worldwide, affecting up to 10% of men and 18% of women over 60 years of age. There has not been a comprehensive review examining modifiable physical risk factors associated with the onset of OA. This evidence is important to inform the physiotherapy management of individuals following onset of OA.

METHODS

Twelve electronic databases were systematically reviewed. The studies selected met the following criteria: (1) original data; (2) joint injury, sport activity, physical activity, overweight/obesity, and/or occupational activity investigated as risk factors; (3) outcomes included OA (hip, knee, and/or ankle); and (4) analytic component of study design. The data extracted included study design, years of follow-up, study population, OA definition, risk factors, and results (effect estimates reported or calculated where available). The quality of evidence was assessed based on a modified version of the Downs and Black checklist.

RESULTS

Joint injury, obesity, and occupational activity were associated with an increased risk of OA of the knee and hip. Sport and physical activity produced inconsistent findings. Joint injury was identified as a significant risk factor for knee OA (combined odds ratio = 3.8; 95% confidence interval: 2.0, 7.2) and hip OA (combined odds ratio = 5.0; 95% confidence interval: 1.4, 18.2), as was previous meniscectomy with or without anterior cruciate ligament injury for knee OA (combined odds ratio = 7.4; 95% confidence interval: 4.0, 13.7). There is a paucity of research examining risk factors associated with ankle OA; this review identified only 2 studies with this outcome.

CONCLUSION

Joint injury, obesity, and occupational activity are associated with an increased risk of knee and hip OA. Some findings remain inconclusive, including levels of physical activity and sport specificity in individuals who do not suffer an injury. Early identification of individuals at risk for OA provides an opportunity for physiotherapy management or other interventions to modify risk-related behavior. There is a need in the literature for additional high-quality studies, such as prospective cohort studies, that minimize potential bias in examining the relationship between physical risk factors and OA.

LEVEL OF EVIDENCE

Prognosis, level 2a-.