Obesity and knee osteoarthritis: new insights provided by body composition studies

Timing Matters: Optimizing the Timeframe for Preoperative Weight Loss to Mitigate Postoperative Infection Risks in Total Knee Arthroplasty

BACKGROUND

We explore the incidence of periprosthetic infections post-total knee arthroplasty (TKA) in morbidly obese patients who achieved weight loss. Current American Academy of Orthopaedic Surgeons guidelines suggest a preoperative body mass index (BMI) below 40 for TKA. This study assesses infection risks in patients initially who had a BMI of 40-50 who reduced their BMI to under 35 at varying intervals prior to surgery.

METHODS

We reviewed a national, all-payer database, PearlDiver, for patients undergoing primary TKA. Patients were stratified based on initial BMI of 40 to 50 and reduction of BMI to less than 35 at 3 months (n = 1,932), 3 to 6 months (n = 794), 6 to 9 months (n = 2,233), and 9 to 12 months (n = 1,194) prior to TKA, as well as patients who had a BMI between 40 to 50 (n = 41,632) on the day of surgery. The nonobese group comprised of patients who had a BMI between 20 and 30 (n = 33,294). Multivariate analyses were performed at one-year follow-up.

RESULTS

We found an increased risk of PJI for patients who had achieved BMI reduction less than nine months prior to TKA, compared to the BMI 20 to 30 cohort at the one-year follow-up (P < .001). Patients who achieved BMI reduction nine to twelve months prior to TKA showed no significant difference in PJI risk compared to the matching nonobese cohort at one-year follow-up (P = .400).

CONCLUSIONS

In conclusion, our results suggest that weight loss should be achieved at least nine months before TKA to decrease infection risks. These findings have significant implications for surgical considerations in obese patients undergoing TKA.

Association of Body Mass Index and Waist Circumference with Osteoarthritis among Korean Adults: A Nationwide Study

BACKGROUND

Evidence on the association between obesity parameters, including body mass index (BMI) and waist circumference (WC), and osteoarthritis is limited. This study aimed to investigate these associations in Korean adults.

METHODS

This nationwide cross-sectional study used data from 24,101 adults aged ≥19 years who participated in the Korea National Health and Nutrition Examination Survey 2016-2020. Odds ratios (ORs) and 95% confidence intervals (CIs) for osteoarthritis according to BMI and WC were analyzed using multivariable logistic regression analyses.

RESULTS

The prevalence of osteoarthritis was higher in individuals with general (10.0%) and abdominal obesity (12.8%) compared with those without. Greater BMI and WC were associated with a higher prevalence (P<0.001) and risk of osteoarthritis (Model 3, P for trend <0.001). Individuals with general and abdominal obesity were associated with a 1.50-fold (OR, 1.50; 95% CI, 1.35-1.67) and 1.64-fold (OR, 1.64; 95% CI, 1.47-1.84) increased risk of osteoarthritis, compared with those without. Similar associations were observed in subgroups according to age, sex, smoking status, and presence of diabetes mellitus. The odds of osteoarthritis 1.73-fold increased (OR, 1.73; 95% CI, 1.53-1.95) in individuals with both general and abdominal obesity compared with those without any of them.

CONCLUSION

Greater BMI, WC, and general and abdominal obesity were associated with an increased risk of osteoarthritis in Korean adults. Appropriate management of abdominal and general obesity may be important to reduce the risk of osteoarthritis.

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSION

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

LEVEL OF EVIDENCE

Level III.

The Length of Incision in Unicondylar Knee Arthroplasty Is More Affected by the Patient's Height Than Their Weight

Objective Obesity leads to osteoarthritis due to increased loading forces on joint cartilage and inflammatory agents released from adipose tissue. In patients with a high body mass index (BMI), during hip and total knee arthroplasty, surgical technical challenges such as longer incisions and wider exposure are encountered, resulting in increased postoperative complications (wound healing problems and infection, venous thromboembolism (VTE)- pulmonary embolism (PE), dislocation, early implant failure) and ultimately decreased patient satisfaction and implant survival. This study investigates whether BMI, height, weight, and patient age are associated with longer incisions in patients undergoing unicondylar knee prosthesis (UKP) placement. Method Between January 2017 and December 2018, 30 patients (29 females and 1 male) who underwent UKP surgery due to medial gonarthrosis were included in the study. The UKP used in the procedures was the Oxford Knee Phase III by Biomet Ltd., UK. The study comprised 43 knees, 13 being bilateral cases, 8 on the right, and 9 on the left. Data regarding the patient's height, weight, BMI, age, and the operated side were collected and compiled. The relationships between these variables and the surgical incision length were statistically analyzed. Results The average age of the patients was 66.3 years, with an average weight and height of 77.6 kg (ranging from 62 to 98 kg) and 167 cm (ranging from 150 to 184 cm), respectively. The lengths of the surgical incisions ranged from 70 mm to 160 mm, with an average length of 124.5 mm. When comparing the incision lengths between the right and left sides, it was observed that the incisions on the left side were longer. The average incision length on the right side was 122.09 mm, while on the left, it was 126.86 mm. Moreover, in the 13 patients who underwent bilateral surgery, this difference in incision length was even more pronounced. The average incision length on the right side was 117.15 mm, whereas on the left, it was 124.23 mm. Bivariate correlation analyses were performed to examine the relationship between the length of the incision and BMI and age. However, no significant relationship was found between the incision length and BMI or age. On the other hand, there was a correlation between the patient's weight values and the incision length (p < 0.05, correlation 0.335). Furthermore, a higher correlation was observed between the patient's height and the incision length (p < 0.01, correlation 0.595). Conclusion The latest advances in surgical techniques and instrumentation have enabled surgeons to perform the procedure using a reliable mini-incision approach. Mid-term evaluation of UKP with mini-incision shows faster recovery and lower morbidity. The findings show that in UKP, the length of the surgical incision is more strongly related to the patient's height than their weight.

Nesfatin-1 suppresses autophagy of chondrocytes in osteoarthritis via remodeling of cytoskeleton and inhibiting RhoA/ROCK signal pathway

Autophagy and cytoskeleton integrity of chondrocytes are a considered as major factors in the progression of osteoarthritis (OA) involving excessive chondrocyte apoptosis and senescence. Nesfatin-1, an adipokine, has been reported to be closely related to cell autophagy and cytoskeleton malfunction. Our previous study found that nesfatin-1 was highly correlated with OA progress in OA patient, and the expression of nesfatin-1 rises in knee articular tissue, serum and chondrocytes. In current study, we aimed to explore the therapeutic effect of nesfatin-1 on OA and its molecular mechanism related to chondrocyte autophagy and cytoskeleton malfunction. We firstly demonstrated that nesfatin-1 effectively suppressed excessive autophagy of OA chondrocytes at both gene and protein levels. Meanwhile, we also found that nesfatin-1 significantly improved cytoskeleton integrity by showing higher F-actin/G-actin ratio, as well as more organized actin fiber structure. Mechanistically, utility of RhoA activator and inhibitor revealed that regulation of autophagy and cytoskeleton integrity via nesfatin-1 was realized via RhoA/ROCK pathway. We also confirmed that nesfatin-1 significantly ameliorated IL-1β induced cartilage degeneration via destabilization of the medial meniscus (DMM) model. Overall, our study indicates that nesfatin-1 might be a promising therapeutic molecule for OA intervention.

Gender related results in total knee arthroplasty: a 15-year evaluation of the Italian population

INTRODUCTION

This study aimed to estimate separately in women and men the number of Total knee arthroplasty (TKA) procedures performed in Italy from 2001 to 2016, exploring specific gender-related characteristics and trends.

MATERIALS AND METHODS

Data of this study were collected from the National Hospital Discharge Reports (NHDR) reported at the Italian Ministry of Health in the years between 2001 and 2016. The information included in this archive are the patient's sex, age, the year when the surgical procedure was performed and the length of the hospitalization.

RESULTS

Between the years 2001 and 2016, a total of 848,863 TKAs have been performed in Italy. TKAs in women passed from 20,719 in 2001 to 49,320 in 2016 showing an increase of 138%, while TKAs in men passed from 6631 in 2001 to 23,601 in 2016 showing an increase of 256%. From the age of 50 onwards, there was a prevalence of procedures in women, from 63.2% in the 50-54 group to 85.7% in the 100 + group. Conversely, under the age of 50, there was a higher percentage of surgeries performed in males, 57.1% on a total of 16,434 TKA surgeries carried out in this age group.

CONCLUSIONS

This study showed that TKA is growing and heavily affecting the female population (70.6% of all TKAs) between 2001 and 2016. However, under 50 years old there was a higher percentage of surgeries performed in males (57.1%). The average number of days of hospitalization in females was higher than in males.

Causal associations of obesity related anthropometric indicators and body compositions with knee and hip arthritis: A large-scale genetic correlation study

Backgrounds

Epidemiological studies have repeatedly investigated the association between obesity related anthropometric indicators and body compositions and osteoarthritis (OA). However, the results have remained inconsistent. This work aimed to investigate the genetic correlation and causal associations of obesity related anthropometric indicators and body compositions with knee and hip OA.

Methods

Single-nucleotide polymorphisms associated with the exposures were searched from the recent genome-wide association studies (GWAS) to obtain full statistics. Summary-level results of knee and hip OA were from the UK Biobank and arcOGEN. First, linkage disequilibrium score regression (LD score regression) was applied to detect the genetic correlation (rg). We further performed a series of sensitivity analyses as validation of primary mendelian randomization (MR) results and the specific evidence of potential causal effects was defined.

Results

We found that genetic components in OA had significant correlation with obesity related traits, except waist-to-hip ratio. In the univariable MR analysis, with the exception of waist-to-hip ratio, obesity related anthropometric indicators were causally associated with increased risks of knee and hip OA. For obesity related body compositions, higher fat-free mass in arm, leg, and whole body increased the risk of knee OA but only fat-free mass in leg showed a significant association with hip OA. Meanwhile trunk fat mass and trunk fat percentage, were associated with knee but not with hip OA. Higher fat mass, and fat percentage in arm, leg, and whole body increased the risk of both knee and hip OA. After adjusting for BMI, the multivariable MR showed maintained results in knee OA. However, in hip OA, only fat mass and fat-free mass in arm, leg, trunk and whole body were significantly associated with the risk of hip OA.

Conclusion

The present study suggests genetic evidence for certain causal associations of obesity related anthropometric indicators and body compositions with knee and hip OA, which may provide important insights for the prevention and treatment on OA.

Utilization of chiropractic services in patients with osteoarthritis and spine pain at a publicly funded healthcare facility in Canada: A retrospective study

BACKGROUND

Osteoarthritis (OA) is one of the most prevalent and disabling musculoskeletal diseases worldwide. There is preliminary evidence from experimental studies and consensus documents that chiropractic management may alleviate spine and/or extremity OA related pain in the short term.

OBJECTIVE

This research explores the potential relationship of a pragmatic course of care, including soft tissue therapy, spinal manipulation, and other treatments commonly delivered by chiropractors, to spine and extremity pain in patients with OA.

METHODS

A retrospective analysis of prospectively collected data from the chiropractic program at a publicly funded healthcare facility was conducted. The primary outcome measures for patients diagnosed with spine and/or extremity OA (n= 76) were numeric pain scores of each spinal and extremity region at baseline and discharge, and a change score was determined.

RESULTS

Statistically significant improvements that exceed a clinically meaningful difference in pain numeric rating scale scores were demonstrated by point change reductions from baseline to discharge visits. Change scores exceeding a minimally clinically important difference of "2-points" were present in the sacroiliac (-2.91), extremity (-2.84), cervical (-2.73), thoracic (-2.61), and lumbar (-2.59) regions.

CONCLUSION

Patients diagnosed with OA in a socioeconomically disadvantaged community demonstrated reductions in mean pain scores in both a clinically meaningful and statistically significant manner concurrent with a course of chiropractic care.

Depressive symptoms and multi-joint pain partially mediate the relationship between obesity and opioid use in people with knee osteoarthritis

OBJECTIVES

To assess the relation of obesity to opioid use in people with or at risk of knee osteoarthritis (OA), and the extent to which this association is mediated by number of painful joints or depressive symptoms.

METHODS

We used data from the Multicenter Osteoarthritis Study, a longitudinal cohort of older adults with or at risk of knee OA. Opioid use was identified by prescription medications and self-report. Obesity was defined as BMI ≥ 30 kg/m2. Multi-joint pain was assessed using a standardized body homunculus, and depressive symptoms using the Center for Epidemiological Studies Depression scale. We quantified the direct and indirect effect of obesity on opioid use through the number of painful joints or depressive symptoms using causal mediation analysis by natural-effects models.

RESULTS

We studied 2,335 participants (mean age: 68; mean BMI 31 kg/m2; 60% women). Persons with obesity had ∼50% higher odds of opioid use than those without. Estimates of indirect (mediated) effect by the number of painful joints and depressive symptoms suggested an increased odds of opioid use by 34% (odds ratio [OR] = 1.34, 95% CI: 1.04, 1.70) and 35% (OR 1.35, 95% CI: 1.05, 1.71), respectively, in obese vs non-obese individuals. The total effect of obesity on opioid use was higher in women than in men.

CONCLUSIONS

Multi-joint pain and depressive symptoms partially explained greater opioid use among obese persons with knee OA, demonstrating that the negative impact of obesity on knee OA extends beyond its influence on knee pain and structural progression.

Colchicine versus Physical Therapy in Knee Osteoarthritis

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

Elderly Runners and Osteoarthritis: A Systematic Review

PURPOSE

The impact of running on the onset of osteoarthritis (OA) is controversial. This study compared the incidence of OA in elderly runners versus nonrunners.

MATERIAL AND METHODS

This systematic review was conducted according to the PRISMA guidelines. PubMed, Google scholar, Embase, and Web of Science databases were accessed in January 2022. All the published clinical studies investigating OA onset in runners versus non-runners were considered. Studies reporting data on OA and participants in other sports were excluded. Only studies investigating patients with a mean age older than 55 years were considered. The methodological quality of the articles was evaluated using the Newcastle-Ottawa Scale (NOS).

RESULTS

Data from 3001 participants and 6674 joints were retrieved. The mean age was 59.4±2.7 years. The mean body mass index was 24.6±2.5 kg/m2. The 5 included articles (963 runners, 2038 nonrunners) did not report significant differences in runners compared with controls.

CONCLUSION

Middle aged runners did not present greater imaging or clinical signs of OA compared with nonrunner controls. Running at elite or recreational level did not increase the rate of OA progression in individuals older than 50 years.

Intensive Physical Activity Increases the Risk of Knee and Hip Arthroplasty: A Systematic Review

PURPOSE

The present study investigated the type of sport and activity level of athletes before they underwent knee and/or hip arthroplasty for osteoarthritis (OA), and compared them with a control group of subjects who did not undergo knee and hip arthroplasty. We hypothesed athletes exposed to high physical loads during sports had the highest risk of developing OA requiring arthroplasty.

MATERIALS AND METHODS

This systematic review was conducted according to the PRISMA guidelines. All the comparative clinical trials to August 2021 investigating the sport activity level between subjects who underwent arthroplasty versus those who did not undergo arthroplasty for OA were considered.

RESULTS

Data from 5 studies and 3638 patients were collected. The mean age for both groups was 47.61±15.5 years, and the mean body mass index was 24.6±2.1 kg/m2 17.6% were women. The Newcastle-Ottawa scale attested good quality of the methodology of the investigations included in the present study.

CONCLUSION

Intense physical exercise, implying a high cumulative number of hours of exercise which can lead to excessive joint overload, in both sexes is associated with greater likelihood of early knee and hip OA which may lead to prosthetic surgery. Moderate and recreational exposure to sport has minor degenerative effects, and is not associated with early onset OA requiring arthroplasty.

Effect of a PA-led arthritis center on hip and knee osteoarthritis care

OBJECTIVE

To evaluate the effect of an arthritis center on patient care and operational throughput.

METHODS

A single-institution, retrospective review was conducted of patients with hip or knee osteoarthritis from January 2016 to October 2019. Our physician assistant (PA) led arthritis center opened in November 2017, and manages nonoperative treatment of osteoarthritis by formulating individualized treatment plans. Descriptive and inferential statistics comparing operational measures, treatment patterns, and patient satisfaction pre- and postcenter opening were performed.

RESULTS

Overall patient volume, new patient volume, and the proportion of new patients seen increased after the arthritis center opened. Encounters per patient and clinicians seen per patient decreased, while the rate of injections and surgery increased. Patient satisfaction improved after opening of the arthritis center.

CONCLUSIONS

The establishment of a dedicated PA-led arthritis center is associated with improved access to care, operational efficiency, and patient satisfaction in patients with hip and knee osteoarthritis.

Obesity Is Preferentially Associated With Patellofemoral Compartment Wear: A Magnetic Resonance Imaging Assessment

BACKGROUND

A well-known association exists between obesity and knee osteoarthritis (OA) for both incidence and progression of the disease. However, the cartilage wear patterns in OA associated with obesity are less well studied.

METHODS

The OA initiative, a prospective sample of 4,796 patients, was used for this study. After the application of inclusion and exclusion criteria, patients were stratified into increasing body mass index (BMI) cohorts (BMI < 25, 25 ≤ BMI < 30, 30 ≤ BMI < 40, and 40 ≤ BMI). Knee MRIs were assessed using the semiquantitative MRI Osteoarthritis Knee Score scores. Patellofemoral (PF), medial, and lateral compartment cartilage scores were compared among BMI cohorts, controlling for confounders using linear regression models.

RESULTS

In total, 2,006 patients were present in our cohort, 773 men (38.5%) and 1,233 women (61.5%); the mean age was 61.7 ± 8.9 years. Increasing BMI was independently associated with increasing grades of PF wear for both right and left knees in the lateral patella facet (right knee β: 0.208, 95% confidence interval [CI]: 0.128 to 0.288, P < 0.001, left knee β: 0.147, 95% CI: 0.056 to 0.237, P = 0.002), medial femoral trochlea (right knee β: 0.135, 95% CI: 0.065 to 0.204, P < 0.001, left knee β: 0.142, 95% CI: 0.063 to 0.221, P < 0.001), and lateral femoral trochlea (right knee β: 0.163, 95% CI: 0.093 to 0.232, P < 0.001, left knee β: 0.147, 95% CI: 0.067 to 0.226, P < 0.001). For the right knee, increasing BMI was associated with medial compartment wear in the posterior femoral area (β: 0.070, 95% CI: 0.015 to 0.126, P = 0.013) and lateral compartment wear in the central tibial area (β: 0.070, 95% CI: 0.002 to 0.138, P = 0.045). For the left knee, increasing BMI was associated with medial compartment wear in the central femoral area (β: 0.093, 95% CI: 0.016 to 0.171, P = 0.018).

DISCUSSION

Obesity is preferentially associated with increasing cartilage wear in the PF compartment in comparison to the tibiofemoral compartment. Physical therapy and exercise programs that promote weight loss should be modified to decrease forces on the PF joint.

Extensive cytokine analysis in synovial fluid of osteoarthritis patients

OBJECTIVE

Osteoarthritis (OA) is a joint disease characterized by articular cartilage loss and afflicts many people worldwide. However, diagnostic methods and treatment options remain limited and are often characterized by low sensitivity and low efficacy. The focus of the present study was to identify proteomic biomarkers in synovial fluid to improve diagnosis and therapy of OA patients.

METHODS

Antibody array technology was utilized for protein expression profiling of synovial fluid from 24 OA patients and 24 healthy persons.

RESULTS

Compared with healthy persons, twenty proteins showed lower expression levels in OA patients, while thirty proteins had higher levels. Among these differential proteins, GITRL, CEACAM-1, FSH, EG-VEGF, FGF-4, PIGF, Cystatin EM and NT-4 were found for the first time to be differentially expressed in OA. Bioinformatics analysis showed that most of these differential proteins were involved leukocytes events, and some differentially expressed proteins including IL-18, CXCL1, CTLA4, MIP-3b, CD40, MMP-1, THBS1, CCL11, PAI-1, BAFF, aggrecan, angiogenin and follistatin were located in central positions of the protein-protein interaction (PPI) network.

CONCLUSION

We speculate that leukocyte proliferation and migration to the joint may be an important pathogenesis of OA, which needs a further validation. The central proteins of the PPI network may play a more pivotal role in OA. The newly identified differentially expressed proteins may be novel biomarkers for OA diagnosis and targets for OA therapy.

A critical review of weight loss recommendations before total knee arthroplasty

OBJECTIVE

Increased infection risk after total knee arthroplasty (TKA) in patients with a higher body mass index (BMI), particularly a BMI ≥40kg/m², suggests that BMI reduction (through weight loss) prior to TKA may be important. However, the impact of weight loss on TKA risk reduction is unclear. Furthermore, weight loss could have detrimental consequences with respect to muscle loss and development of sarcopenic obesity, whereby a potential weight loss paradox in adults with advanced knee OA and obesity may be present. Using a critical review approach, we examined the current evidence supporting weight loss in adults with obesity and advanced knee osteoarthritis (OA). We focused on three key areas: (1) TKA complication risk with severe obesity compared to obesity (BMI ≥40kg/m² versus 30.0-39.9kg/m²); (2) weight loss recommendations for individuals with advanced knee OA; and (3) TKA outcomes after pre-surgical weight loss.

METHODS

Medline and CINAHL databases were examined from Jan 2010 to May 2020 to identify high-level and/or clinically-influential evidence (systematic reviews, meta-analyses and clinical practice guidelines).

RESULTS

The literature does not show a clear relationship between weight loss and reduction in TKA complications, and no indication that a patients' individual risk is lowered by reducing their BMI from a threshold of ≥40kg/m² to ≤39.9kg/m². Studies that have found a benefit of weight loss for knee OA have not included patients with higher BMIs (≥40kg/m²) or more advanced knee OA. Furthermore, there is unclear evidence of a benefit of pre-surgical weight loss on TKA outcomes. These are important evidence gaps, suggesting that recommendations for BMI reduction prior to TKA should be tempered by the current uncertainty in the literature.

CONCLUSION

Evidence to support a benefit of weight loss prior to TKA is lacking. Until knowledge gaps are clarified, it is recommended that practitioners consider individual patient needs and risk before recommending weight loss (and therefore BMI reduction).

Knee Injuries in Normal-Weight, Overweight, and Obese Runners: Does Body Mass Index Matter?

OBJECTIVE

To investigate whether the proportion of running-related knee injuries differed in normal-weight, overweight, and obese runners.

DESIGN

Comparative study.

METHODS

Data from 4 independent prospective studies were merged (2612 participants). The proportion of running-related knee injuries out of the total number of running-related injuries was calculated for normal-weight, overweight, and obese runners, respectively. The measure of association was absolute difference in proportion of running-related knee injuries with normal-weight runners as the reference group.

RESULTS

A total of 571 runners sustained a running-related injury (181 running-related knee injuries and 390 running-related injuries in other anatomical locations). The proportion of running-related knee injuries was 13% lower (95% confidence interval: -22%, -5%; P = .001) among overweight runners compared with normal-weight runners. Similarly, the proportion of running-related knee injuries was 12% lower (95% confidence interval: -23%, -1%; P = .042) among obese runners compared with normal-weight runners.

CONCLUSION

Overweight and obese runners had a lower proportion of running-related knee injuries than normal-weight runners. J Orthop Sports Phys Ther 2020;50(7):397-401. doi:10.2519/jospt.2020.9233.

How to Choose Platelet-Rich Plasma or Hyaluronic Acid for the Treatment of Knee Osteoarthritis in Overweight or Obese Patients: A Meta-Analysis

Objective

The purpose of this meta-analysis was to determine whether platelet-rich plasma (PRP) was better than hyaluronic acid (HA) for the treatment of knee osteoarthritis (OA) in overweight or obese patients.

Design

Two reviewers independently used the keywords combined with free words to search English-based electronic databases according to Cochrane Collaboration guidelines, such as PubMed, Embase, ScienceDirect, and Cochrane library. The pooled data were analyzed using RevMan 5.3.

Results

Ten randomized controlled trials (RCTs) with 1096 patients were included. During the first two months of follow-up, there was no significant difference between the two groups. At the 3rd, 6th, and 12th months of follow-up, the pooled analysis showed that PRP was better than HA for the treatment of knee OA in overweight or obese patients. There were significant differences between the two groups at Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) total score (3 months: MD = -1.35, [95% CI: -2.19 to -0.50], P=0.002, I 2 = 0%; 6 months: MD = -7.62, [95% CI: -13.51 to -1.72], P=0.01, I 2 = 88%; 12 months: MD = -12.11, [95% CI: -20.21 to -4.01], P=0.003, I 2 = 94%).

Conclusions

For overweight or obese patients with knee OA, intra-articular injection of PRP in a short time was not necessarily superior to HA, but long-term use was better than HA in pain and functional relief.

Treat-to-target strategy for knee osteoarthritis. International technical expert panel consensus and good clinical practice statements

Background:

In this work, we aimed to establish a clinical target in the management of knee osteoarthritis (KOA) and to propose good clinical practice (GCP) statements for carrying out a treat-to-target strategy.

Methods:

A steering committee of seven experts had formulated a provisional set of recommendations that were exposed for discussion and modification to a technical expert panel (TEP) of 25 multidisciplinary experts from Europe, North America, South America and Asia. The level of evidence and strength of each recommendation was discussed. The TEP formulated overarching principles and GCP statements based on the level of agreement for each item with a vote using a 10-point numerical scale.

Results:

Two overarching principles and 10 GCP statements were formulated by the TEP. These GCP statements suggest: treatment should achieve clinical improvement bringing the patient to the Patient Acceptable Symptom State (PASS); pharmacological and nonpharmacological treatment should begin as early as possible, with an early diagnosis of symptomatic KOA; the patient should be evaluated every 3–6 months; risk factors of KOA progression should be identified and managed with patients at the beginning of the treatment and monitored regularly; treatment should be adapted according to patient phenotype and disease severity; healthy lifestyle must be promoted and monitored. The level of agreement average ranged from 8.7 to 9.6 on scale.

Conclusions:

The proposed overarching principles and GCP statements have the aim of involving patients, general practitioners and multidisciplinary specialists in sharing a therapeutic treat-to-target strategy for KOA management based on the best evidence and expert opinions.

The different influence of high levels of physical activity on the incidence of knee OA in overweight and obese men and women-a gender specific analysis

OBJECTIVE

To investigate the influence of physical activity on incidence of knee osteoarthritis (OA) in overweight and obese men and women.

DESIGN

Data were extracted from the Osteoarthritis Initiative cohort on 1,667 participants without symptomatic knee OA at baseline. We used logistic regression and marginal effect models to estimate the effect of body mass index (BMI) and reported physical activity score, together with the interaction between them, on the development of radiographic knee OA, symptomatic knee OA and joint space narrowing (JSN) after 96-months.

RESULTS

Men in the most active quartile had almost double the likelihood of knee OA, independent of OA definition [e.g., odds ratio (OR) 2.4 (95%CI: 1.2-4.5) for radiographic knee OA]. Interaction analyses showed statistically significant interactions between physical activity and BMI on developing knee OA (i) radiographic OA _interaction(P = 0.039), (ii) symptomatic OA _interaction(P = 0.022), (iii) JSN _interactionP = 0.012). The margin plots in men also demonstrated that the effect of physical activity on different measures of knee OA were modified by high levels of BMI. These effects were not mirrored in women where at all BMI levels, the level of reported physical activity did not influence likelihood of knee OA independent of OA definition.

CONCLUSIONS

In overweight and obese men, there appears to be a threshold above which increasing levels of physical activity are associated with higher risk of knee OA. This is absent in women.

The role of thermal balneotherapy in the treatment of obese patient with knee osteoarthritis

Osteoarthritis (OA) is the most common form of arthritis clinically characterized by joint pain, functional limitation, and reduced quality of life. Several studies have shown a clear link between obesity and higher risk of knee OA. According to the multifactorial OA pathogenesis, the management of this condition requires a multidisciplinary approach. The objective of this study is to evaluate hydrokinesitherapy effects in thermal setting in obese patients with knee OA. Fifty-three patients were assessed for eligibility, of which 33 refused the treatment, while 10 patients dropped out after the enrollment for personal reasons or inability to adhere to the program. Ten patients (8 females, 2 males, mean age of 59.4 years) with obesity (range BMI 30-45 kg/m2) and knee OA (II-III grade of Kellgren-Lawrence scale) treated with hydrokinetic therapy in thermal water (two sessions per week for 8 consecutive weeks) completed the study. Primary outcome measure was pain (VAS). Secondary outcomes were clinical knee evaluation (range of motion-ROM, lower-limb muscle strength), WOMAC, and Lequesne Algofunctional Index. Patellar tendon and peri-articular soft tissue ultrasound evaluation and gait analysis at baseline (T0), at the end of treatment (T1), and at 6 months of follow-up (T2) were performed. Significant decrease on VAS pain during walking on a flat surface and going up/down stairs was reached from baseline at T1 (p = 0.0039; p = 0.0098) and was maintained at T2 (p = 0.00954) exclusively for VAS pain during walking on a flat surface. WOMAC score showed a significant reduction between T0 and T1 (p = 0.0137) and between T0 and T2 (p = 0.006438), as ROM evaluations. Kinematic path assessment did not show significant results in individual gait steps, except for the space-time variables of the average speed and the values of ground reaction force (GRF) obtained with force platforms. Hydrokinesitherapy in thermal environment in obese patients with knee OA may determine pain relief, joint function improvement, and walking speed increase until 6 months of follow-up.

Review of Prospects of Biological Fluid Biomarkers in Osteoarthritis

Osteoarthritis (OA) is a degenerative disease of the joints and is one of the leading causes of disability in adults. However, there are no key therapeutics for OA and medical treatment is based on managing the symptoms and slowing down progression of the disease. Diagnostics based on clinical examination and radiography have provided little information about metabolic changes in joint tissues, disease onset and progression. Due to lack of effective methods for early detection and evaluation of treatment outcome, the measurement of biochemical markers (biomarkers) shows promise as a prospective method aiding in disease monitoring. OA biomarkers that are present in biological fluids such as blood, urine and synovial fluid, sources that are easily isolated from body, are of particular interest. Moreover, there are increasingly more studies identifying and developing new biomarkers for OA. In this review, efforts have been made to summarize the biomarkers that have been reported in recent studies on patients. We also tried to classify biomarkers according to tissue metabolism (bone, cartilage and synovial metabolism markers), pathological pathways (inflammatory and genetic markers) and biological function (chemokines, growth factors, acute phase proteins, etc.).

Mediating role of body mass index in knee osteoarthritis

Objective

This study explores the role of knee circumference, body mass index (BMI), and range of motion (ROM) in predicting knee osteoarthritis (KOA). The objective is to elucidate the mediating role of BMI in influencing the relationship between age, knee circumference and pain in knee osteoarthritis, as measured with the help of the knee outcome survey (KOS) questionnaire.

Methods

The design used in this study was causal comparative. The study consisted of 66 patients with symptomatic KOA and 60 matched asymptomatic individuals.

Result

BMI was significantly and positively correlated with both pain and knee girth for the symptomatic KOA group. This finding signifies a relationship between KOA and other indicators, such as age and knee circumference.

Conclusions

The results of the study would indicate an important milestone in clinical rehabilitation, especially for physical therapists, enabling them to plan, modify, and design interventions to improve the health status of KOA patients.

Molecular genetics of human obesity: A comprehensive review

Obesity and its related health complications is a major problem worldwide. Hypothalamus and their signalling molecules play a critical role in the intervening and coordination with energy balance and homeostasis. Genetic factors play a crucial role in determining an individual's predisposition to the weight gain and being obese. In the past few years, several genetic variants were identified as monogenic forms of human obesity having success over common polygenic forms. In the context of molecular genetics, genome-wide association studies (GWAS) approach and their findings signified a number of genetic variants predisposing to obesity. However, the last couple of years, it has also been noticed that alterations in the environmental and epigenetic factors are one of the key causes of obesity. Hence, this review might be helpful in the current scenario of molecular genetics of human obesity, obesity-related health complications (ORHC), and energy homeostasis. Future work based on the clinical discoveries may play a role in the molecular dissection of genetic approaches to find more obesity-susceptible gene loci.

Pathophysiology of obesity on knee joint homeostasis: contributions of the infrapatellar fat pad

Osteoarthritis (OA) is a debilitating condition characterized by inflammation, breakdown, and consequent loss of cartilage of the joints. Epidemiological studies indicate obesity is an important risk factor involved in OA initiation and progression. Traditional views propose OA to be a biomechanical consequence of excess weight on weight-bearing joints; however, emerging data demonstrates that systemic and local factors released from white adipose depots play a role. Hence, current views characterize OA as a condition exacerbated by a metabolic link related to adipose tissue, and not solely related to redistributed/altered weight load. Factors demonstrated to influence cartilage and bone homeostasis include adipocyte-derived hormones (“adipokines”) and adipose depot released cytokines. Epidemiological studies demonstrate a positive relation between systemic circulating cytokines, leptin, and resistin with OA types, while the association with adiponectin is controversial. Local factors in joints have also been shown to play a role in OA. In particular, this includes the knee, a weight-bearing joint that encloses a relatively large adipose depot, the infrapatellar fat pad (IFP), which serves as a source of local inflammatory factors. This review summarizes the relation of obesity and OA as it specifically relates to the IFP and other integral supporting structures. Overall, studies support the concept that metabolic effects associated with systemic obesity also extend to the IFP, which promotes inflammation, pain, and cartilage destruction within the local knee joint environment, thus contributing to development and progression of OA.

Vastus medialis fat infiltration - a modifiable determinant of knee cartilage loss

BACKGROUND

There is growing interest in the role of intramuscular fat and how it may influence clinical outcomes. Vastus medialis (VM) is a functionally important quadriceps muscle that helps to stabilise the knee joint. This longitudinal study examined the determinants of VM fat infiltration and whether VM fat infiltration influenced knee cartilage volume.

METHODS

250 participants without any diagnosed arthropathy were assessed at baseline between 2005 and 2008, and 197 participants at follow-up between 2008 and 2010. Ambulatory and sporting activity were assessed and magnetic resonance imaging (MRI) was used to determine knee cartilage volume and VM fat infiltration.

RESULTS

Age, female gender, BMI and weight were positively associated with baseline VM fat infiltration (P ≤ 0.03), while ambulatory and sporting activity were negatively associated with VM fat infiltration (P ≤ 0.05). After adjusting for confounders, a reduction in VM fat infiltration was associated with a reduced annual loss of medial tibial (β = -10 mm(3); 95% CI -19 to 0 mm(3); P = 0.04) and patella (β = -18 mm(3); 95% CI -36 to 0 mm(3); P = 0.04) cartilage volume.

CONCLUSION

This community-based study of healthy adults has shown that VM fat infiltration can be modified by lifestyle factors including weight loss and exercise, and reducing fat infiltration in VM has beneficial effect on knee cartilage preservation. The findings suggest that modifying VM fat infiltration via lifestyle interventions may have the potential to reduce the risk of knee OA.

Meniscus is more susceptible than cartilage to catabolic and anti-anabolic effects of adipokines

OBJECTIVE

This study compared the effects on cartilage and meniscus matrix catabolism and biosynthesis of several adipokines implicated in osteoarthritis (OA).

DESIGN

Bovine cartilage and meniscus explants were cultured for 1 or 9 days in serum-free medium alone or with 0.02, 0.2, or 2 μg/ml of leptin, visfatin, adiponectin, or resistin. Media were supplemented with (3)H-proline or (35)S-sodium sulfate to evaluate protein and sulfated glycosaminoglycan (sGAG) accumulation on the last day of culture. Explants were assayed for radiolabel, sGAG, and DNA contents. Cultured media were assayed for sGAG, nitrite and lactate dehydrogenase.

RESULTS

Cartilage tissue was minimally affected by adipokines, with only the highest resistin dose increasing sGAG release and nitrite production compared to controls. In sharp contrast, meniscus tissue was responsive to several adipokines, with elevated sGAG and nitrite release following treatment with resistin, leptin, or visfatin. Cartilage sGAG content was unaltered by adipokine treatment whereas meniscal sGAG content significantly decreased with resistin dosage. Protein ((3)H) incorporation was unaffected by adipokine treatment in both tissues. sGAG ((35)S) incorporation did not significantly vary with adipokine treatment in cartilage but was inhibited by treatment with leptin, visfatin, and resistin in meniscus.

CONCLUSION

Our results indicate that meniscal tissue is more susceptible to adipokine-stimulated catabolism than is cartilage. Resistin had the strongest effect of the adipokines tested, inducing sGAG release in both tissues and depleting sGAG content in meniscus. These results suggest that increased adipokine levels due to obesity or joint injury may alter the mechanical integrity of the knee joint through biological pathways.

Musculoskeletal Pain, Self-reported Physical Function, and Quality of Life in the Teen-Longitudinal Assessment of Bariatric Surgery (Teen-LABS) Cohort

IMPORTANCE

Obesity is associated with chronic musculoskeletal pain and is a risk factor for disability and osteoarthritis.

OBJECTIVES

To describe the prevalence, sites, and intensity of musculoskeletal pain in adolescents with severe obesity; to evaluate associations between musculoskeletal pain and self-reported physical function as well as weight-related quality of life; and to evaluate the association between musculoskeletal pain and high-sensitivity C-reactive protein level.

DESIGN, SETTING, AND PARTICIPANTS

Teen-Longitudinal Assessment of Bariatric Surgery (Teen-LABS) is a prospective, observational study that collects standardized data on adolescents undergoing weight loss surgery at 5 US centers. We examined baseline data from this cohort between February 28, 2007, and December 30, 2011. We excluded adolescents with Blount disease and slipped capital femoral epiphyses. A total of 233 participants were included in these analyses.

MAIN OUTCOMES AND MEASURES

We assessed musculoskeletal pain and pain intensity of the lower back, hips, knees, and ankles/feet using the visual analog scale, categorizing musculoskeletal pain into lower back pain, lower extremity (hips, knees, and feet/ankles combined) pain, and no pain. We assessed self-reported physical function status with the Health Assessment Questionnaire Disability Index and assessed weight-related quality of life with the Impact of Weight on Quality of Life-Kids measure. We adjusted for sex, race, age at surgery, body mass index (BMI; calculated as weight in kilograms divided by height in meters squared), and clinical depressive symptoms in regression analyses.

RESULTS

Among the 233 participants, the mean (SD) age at surgery was 17.1 (1.56) years and the median BMI was 50.4. Participants were predominantly female (77%), white (73%), and non-Hispanic (93%). Among the participants, 49% had poor functional status and 76% had musculoskeletal pain. Lower back pain was prevalent (63%), followed by ankle/foot (53%), knee (49%), and hip (31%) pain; 26% had pain at all 4 sites. In adjusted analyses, compared with pain-free participants, those reporting lower extremity pain had greater odds of having poor physical function according to scores on the Health Assessment Questionnaire Disability Index (odds ratio = 2.82; 95% CI, 1.35 to 5.88; P < .01). Compared with pain-free participants, those reporting lower extremity pain had significantly lower Impact of Weight on Quality of Life-Kids total scores (β = -9.42; 95% CI, -14.15 to -4.69; P < .01) and physical comfort scores (β = -17.29; 95% CI, -23.32 to -11.25; P < .01). After adjustment, no significant relationship was observed between musculoskeletal pain and high-sensitivity C-reactive protein level.

CONCLUSIONS AND RELEVANCE

Adolescents with severe obesity have musculoskeletal pain that limits their physical function and quality of life. Longitudinal follow-up will reveal whether weight loss surgery reverses pain and physical functional limitations and improves quality of life.

The role of obesity duration on the association between obesity and risk of physical disability

OBJECTIVE

To relate measured obesity duration in mid-life with subsequent incidence of physical disability over and above body mass index (BMI) attained.

METHODS

Framingham Offspring Study is a longitudinal study that began in 1971. Examination 5 (1991-1995; "baseline") and disability onset ascertained from examinations 6-8 (2008) were used. About 2,095 disability-free participants aged 45-65 years at baseline were included. Obesity (BMI ≥ 30 kg/m(2) ) duration was calculated between examination 1 and examination 5. Cox regression was used to analyze time to disability.

RESULTS

204 participants developed disability (incidence rate=7.9 per 1,000 person-years). Obesity duration ranged from 0 to 22 years (mean of 2.0 years overall, 8.3 years for those with baseline obesity). Obesity duration increased risk of new disability (hazard ratio [HR] 1.07 per year of obesity; 95% confidence interval [CI] 1.05-1.09). This association was attenuated on further adjustment for baseline BMI (HR 1.03; 95% CI 1.00-1.06).

CONCLUSIONS

Being obese for longer during mid-life increases the risk of later-life disability over and above attained BMI. These results support the need for prevention of weight gain in young adults to avoid an increasing burden of physical disability in later life.

Metabolic triggered inflammation in osteoarthritis

Osteoarthritis (OA) is a common chronic joint disorder with a multifactorial etiology including genetic and environmental factors. Metabolic triggered inflammation, induced by nutrient overload and metabolic surplus, consists of components such as obesity, pro-inflammatory cytokines and adipokines, abnormal metabolites, acute phase proteins, vitamin D deficiency, and deregulated microRNAs that may play a role in OA pathophysiology. Obesity-related metabolic factors, especially adipokines, contribute to OA development by inducing pro-inflammatory cytokines and degradative enzymes, leading to cartilage matrix impairment and subchondral bone remodeling. Ectopic metabolite deposition and low-grade systemic inflammation can contribute to a toxic internal environment that exacerbates OA. Complement components highly expressed in osteoarthritic joints have also been proposed as causative factors. Vitamin D deficiency has been associated with obesity and is implicated to be associated with cartilage loss in OA. Metabolic microRNAs may explain the inflammatory link between obesity and OA. Therapies targeting metabolic-triggered inflammation and its components are anticipated to have potential for the treatment of OA.

The role of fat mass and skeletal muscle mass in knee osteoarthritis is different for men and women: the NEO study

OBJECTIVE

To investigate if the amount of fat mass (FM) or skeletal muscle mass (SMM) is more strongly associated with knee osteoarthritis (OA), in both men and women.

METHODS

The Netherlands Epidemiology of Obesity (NEO) study is a population-based cohort aged 45-65 years, including 5313 participants (53% female, median body mass index (BMI) 29.9 kg/m(2)). FM (kg), fat percentage, SMM (kg) and skeletal muscle (SM) percentage were estimated using bioelectrical impedance analysis (BIA). Clinical OA was defined following the ACR criteria. Structural OA was defined based on magnetic resonance imaging (MRI) in 1142 participants. Logistic regression analyses were used to examine the associations of all body composition measures with clinical and structural knee OA per standard deviation (SD), stratified by sex and adjusted for age and height.

RESULTS

Clinical or structural OA was present in 25% and 14% of women and 12% and 13% of men, respectively. FM and fat percentage were positively associated with clinical knee OA in men and women. SMM was positively associated, while the SM percentage was negatively associated with clinical OA in both men and women. The FM/SMM ratio was positively associated with clinical OA. All determinants showed even stronger ORs for structural knee OA. In men, SMM was more strongly associated with knee OA as compared to FM whereas in women, FM was most strongly associated.

CONCLUSION

Especially a high FM/SMM ratio seems to be unfavorable in knee OA. In men, SMM is most strongly associated with knee OA whereas in women FM seems to be of most importance.

Adiposity and hand osteoarthritis: the Netherlands Epidemiology of Obesity study

Introduction

Obesity, usually characterized by the body mass index (BMI), is a risk factor for hand osteoarthritis (OA). We investigated whether adipose tissue and abdominal fat distribution are associated with hand OA.

Methods

The Netherlands Epidemiology of Obesity (NEO) study is a population-based cohort aged 45 to 65 years, including 5315 participants (53% women, median BMI 29.9 kg/m²). Fat percentage and fat mass (FM) (kg) were estimated using bioelectrical impedance analysis. The waist-to-hip ratio (WHR) was calculated. In 1721 participants, visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT) (cm²) were assessed using abdominal MR imaging. Hand OA was defined according to the ACR criteria.

Odds ratios (OR) with 95% confidence intervals (CI) were calculated for the association of fat percentage, FM, WHR, VAT and SAT with hand OA using logistic regression analyses per standard deviation, stratified by sex and adjusted for age.

Results

Hand OA was present in 8% of men and 20% of women. Fat percentage was associated with hand OA in men (OR 1.34 (95% CI 1.11 to 1.61)) and women (OR 1.26 (1.05 to 1.51)), as was FM. WHR was associated with hand OA in men (OR 1.45 (1.13 to 1.85)), and to a lesser extent in women (OR 1.17 (1.00 to 1.36)). Subgroup analysis revealed that VAT was associated with hand OA in men (OR1.33 (1.01 to 1.75)). This association increased after additional adjustment for FM (OR 1.51 (1.13 to 2.03)).

Conclusions

Fat percentage, FM and WHR were associated with hand OA. VAT was associated with hand OA in men, suggesting involvement of visceral fat in hand OA.

The Efficacy of Continuous Versus Intermittent Celecoxib Treatment in Osteoarthritis Patients with Body Mass Index ≥30 and <30 kg/m(2.)

Objective:

Characterize the effect of body mass index (BMI) on the efficacy of continuous daily celecoxib treatment compared with intermittent celecoxib treatment.

Methods:

Prespecified exploratory analysis of a 24-week, double-blind, parallel-group, randomized, multicenter international study. 858 patients with knee or hip osteoarthritis (OA) were randomized to receive celecoxib 200 mg daily either as continuous or intermittent treatment. Efficacy was measured by Western Ontario and McMaster Universities Arthritis Index (WOMAC) total and subscale scores and the number of flare events.

Results:

Least squares mean increases (worsening) in WOMAC total scores were significantly less in the continuous treatment group than in the intermittent treatment group in patients with a BMI <30 kg/m² (1.33 vs 4.85; p=0.016) and in patients with a BMI ≥30 kg/m² (1.84 vs 5.12; p=0.019). There was a greater worsening in patients with a BMI ≥30 kg/m² than in those with a BMI <30 kg/m² in both the continuous and intermittent groups. Fewer flares were reported in the continuous treatment group than in the intermittent group in patients with a BMI <30 kg/m² (0.55 vs 0.88; p<0.0001) and ≥30 kg/m² (0.54 vs 0.97; p<0.0001). There were no differences in adverse events in the two BMI groups.

Conclusions:

Continuous celecoxib treatment was significantly more efficacious than intermittent use in patients with a BMI <30 kg/m² compared with obese patients (≥30 kg/m²) as assessed by WOMAC total scores and the number of flares. These data suggest that including weight loss as part of a treatment regimen for obese OA patients could be important.

Obesity and total joint arthroplasty: a literature based review

The prevalence of obesity in the population is unlikely to decline, and is likely to contribute to the increasing demand for hip or knee arthroplasty. Conflicting data exist on the risk and benefits of total joint arthroplasty in obese patients. The purpose of this manuscript is to define and identify areas of concern for obese patients undergoing total joint arthroplasty. A workgroup of total joint arthroplasty surgeons from the American Association of Hip and Knee Surgeons (AAHKS) was tasked with identifying key questions regarding obesity and total joint arthroplasty. The workgroup evaluated the available literature and sought to create a review regarding obesity and total joint arthroplasty to complement and guide the surgeon-patient discussion in addition to identifying areas of future research.

Increased susceptibility of Trpv4-deficient mice to obesity and obesity-induced osteoarthritis with very high-fat diet

OBJECTIVE

To test the hypotheses that: (1) the transient receptor potential vanilloid 4 (TRPV4) ion channel is protective in the obesity model of osteoarthritis (OA), resulting in more severe obesity-induced OA in Trpv4 knockout (Trpv4(-/-)) mice; and (2) loss of TRPV4 alters mesodermal stem cell differentiation.

METHODS

Male Trpv4(-/-) and wild-type (Trpv4(+/+)) mice were fed a control or high-fat diet (10% kcal and 60% kcal from fat, respectively) for 22 weeks, at which time spontaneous cage activity and severity of knee OA were evaluated. In addition, the adipogenic, osteogenic and chondrogenic potential of bone marrow-derived (MSC) and adipose-derived (ASC) stem cells from Trpv4(-/-) and Trpv4(+/+) mice were compared.

RESULTS

A high-fat diet significantly increased knee OA scores and reduced spontaneous cage activity in Trpv4(-/-) mice, while also increasing weight gain and adiposity. MSCs from Trpv4(-/-) mice had decreased adipogenic and osteogenic differentiation potential versus Trpv4(+/+) MSCs. ASCs from Trpv4(-/-) mice had increased adipogenic and osteogenic and reduced chondrogenic differentiation potential versus Trpv4(+/+) ASCs.

CONCLUSIONS

Pan-Trpv4(-/-) mice develop more severe OA with high-fat feeding, potentially due to more severe diet-induced obesity. The altered differentiation potential of Trpv4(-/-) progenitor cells may reflect the importance of this ion channel in the maintenance and turnover of mesodermally-derived tissues.

Lower limbs composition and radiographic knee osteoarthritis (RKOA) in Chingford sample--a longitudinal study

Our aim in this longitudinal study was to evaluate to what extent fat and lean tissue mass variations are associated and can predict RKOA in a large sample of British women followed-up over 10 years. Kellgren/Lawrence (K/L), joint space narrowing (JSN) and osteophyte (OSP) grades were scored from radiographs of both knees in 909 middle-aged women from the Chingford registry. Body composition components were assessed using the dual energy X-ray absorptiometry (DXA) method. In cross-sectional analysis, combined effect of age, BMI and leg tissue composition was required for best fitting model explaining variations of K/L scoring and osteophytes at lateral compartment. To explain medial osteophytes, age and BMI were sufficient to generate the best fitting model. In prediction analysis, leg lean mass was the more powerful predictor of K/L, medial osteophytes than BMI. In conclusion, BMI appears to influence the development of knee OA through both fat and/or lean mass, depending on RKOA phenotype.

Body fat is associated with increased and lean mass with decreased knee cartilage loss in older adults: a prospective cohort study

OBJECTIVE

To determine the associations between body composition at baseline and knee cartilage loss over 2.9 years in older adults.

METHODS

A total of 395 randomly selected subjects (mean 62 years, range 51-81, 50% female) were studied at baseline and 2.9 years later. T1-weighted fat-suppressed magnetic resonance imaging of the right knee was performed to determine knee cartilage volume and tibial bone area at baseline and follow-up. Height, weight and radiographic osteoarthritis were measured by standard protocols at baseline. Fat mass and lean mass were measured by dual-energy X-ray absorptiometry at baseline.

RESULTS

Tibial cartilage volume decreased by 2.0-2.7% per annum. In multivariable analysis, annual change in medial cartilage volume was negatively and significantly associated with body mass index (β: -0.14% per kg m(-2), 95% confidence interval (CI): -0.25%, -0.02%), percentage total body fat (β: -0.19% per %, 95% CI: -0.30%, -0.07%) and percentage trunk fat (β: -0.10% per %, 95% CI: -0.19%, -0.02%), and positively associated with percentage lean mass (β: 0.20% per %, 95% CI: 0.08%, 0.32%). Change in lateral tibial cartilage volume was also significantly associated with percentage total body fat (β: -0.11% per %, 95% CI: -0.21%, -0.001%) and total lean mass (β: 0.13% per kg, 95% CI: 0.04%, 0.22%). These were independent of sex and age even though both were also significant predictors.

CONCLUSIONS

Body fat adversely affects tibial cartilage loss over time, whereas lean mass is protective. Strategies aimed at reducing body fat but increasing lean mass may reduce knee cartilage loss in older people.

Obesity and knee osteoarthritis are not associated with impaired quadriceps specific strength in adults

OBJECTIVE

To assess whether adults, aged 50-59 years, who are obese or moderately to severely obese have impaired quadriceps strength and muscle quality in comparison with adults who are not obese, both groups with and without knee osteoarthritis (OA).

DESIGN

Cross-sectional observational study.

SETTING

Rural community acquired sample.

SUBJECTS

Seventy-seven men and 84 women, aged 50-59 years.

METHODS

Comparisons by using mixed models for clustered data (2 lower limbs per participant) between groups defined by body mass index (BMI) (<30 kg/m(2), 30-35 kg/m(2), and ≥35 kg/m(2)), with and without knee OA MAIN OUTCOME MEASUREMENT: The slope of the relationship between quadriceps muscle cross-sectional area (CSA) and isokinetic knee extensor strength (dynamometer) in each BMI and OA group.

RESULTS

There were 113 limbs (48.7% women), 101 limbs (38.6% women), and 89 limbs (73.0% women) in the <30 kg/m(2), 30-35 kg/m(2), and ≥35 kg/m(2) BMI groups, respectively; knee OA was present in 10.6%, 28.7%, and 58.4% of the limbs in each of these respective groups. Quadriceps CSA did not significantly differ among BMI groups in either gender or between subjects with and without knee OA. Peak quadriceps strength also did not significantly differ by BMI group or by the presence of knee OA. Multivariable analyses also demonstrated that peak quadriceps strength did not differ by BMI group, even after adjusting for (a) gender, (b) OA status, (c) intramuscular fat, or (d) quadriceps attenuation. The slopes for the relationships between quadriceps strength and CSA did not differ by BMI group, OA status, or their interaction.

CONCLUSIONS

Individuals who were obese and at risk for knee OA did not appear to have altered muscle strength or muscle quality compared with adults who were not obese and were aged 50-59 years. The absence of a difference in the relationship between peak quadriceps strength and CSA provided further evidence that there was not an impairment in quadriceps muscle quality in this cohort, which suggests that factors other than strength might mediate the association between obesity and knee OA.

Association of Baseline Knee Bone Size, Cartilage Volume, and Body Mass Index with Knee Cartilage Loss Over Time: A Longitudinal Study in Younger or Middle-aged Adults

Objective.

To determine the association of knee bone size, cartilage volume, and body mass index (BMI) at baseline with knee cartilage loss over 2 years in younger or middle-aged adults.

Methods.

A total of 324 subjects (mean age 45 yrs, range 26–61) were measured at baseline and about 2 years later. Knee cartilage volume and bone size were determined using T1-weighted fat-saturated magnetic resonance imaging.

Results.

In multivariable analysis, baseline knee bone size was negatively associated with annual change in knee cartilage volume at medial and lateral tibial sites (ß = −0.62% to −0.47%/cm2, all p < 0.001). The associations disappeared at medial tibial site after adjustment for baseline cartilage volume and became of borderline statistical significance at lateral tibial site after adjustment for both baseline cartilage volume and osteophytes (ß = −0.29, p = 0.059). Baseline knee cartilage volume was consistently and negatively associated with annual change in knee cartilage volume at all 3 medial tibial, lateral tibial, and patellar sites (ß = −4.41% to −1.37%/ml, all p < 0.001). Baseline BMI was negatively associated with an annual change in knee cartilage volume, but only in subjects within the upper tertile of baseline cartilage volume, even after adjusting for cartilage defects (ß = −0.16% to −0.34%/kg/m2, all p < 0.05).

Conclusion.

Our study suggests that both higher baseline tibial bone area and knee cartilage volume (most likely due to cartilage swelling) are associated with greater knee cartilage loss over 2 years. A higher BMI was associated with greater knee cartilage loss only in subjects with higher baseline cartilage volume.

Clinical Implications for Muscle Strength Differences in Women of Different Age and Racial Groups: The WIN Study

BACKGROUND: Reduction in muscle strength is strongly associated with functional decline in women, and women with lower quadriceps strength adjusted for body weight are more likely to develop knee osteoarthritis. OBJECTIVE: To compare body weight--adjusted strength among women of different age/racial groups. STUDY DESIGN: Cross-sectional study of muscle strength in 918 women aged 20--83 (M ± SD = 52 ± 13). METHODS: An orthopedic examination was conducted including measurement of handgrip and lower extremity strength (hip abductors/external rotators, knee flexors/extensors). Data were grouped into young (20--39 years, n = 139), middle (40--54 years, n = 300), and older (55+ years, n = 424) ages for white (n = 699) and African American (AA) (n = 164) women. Means and standard deviations for strength adjusted for body weight were calculated for each age and racial group and compared using 2-way multivariate analysis of variance and post hoc tests. RESULTS: No significant age-by-race interaction (P = .092) but significant main effects for age and race (P < .001). Pairwise comparisons revealed significant differences in knee extensor and flexor strength between all age groups. For grip and hip external rotator strength, significant differences were found between the middle and older groups. Differences in hip abductor strength were found between the young and middle-aged groups. AA women had lower strength than white women in all muscle groups (P < .05) except hip external rotators. CONCLUSIONS: Strength decreased with age in all muscle groups but magnitude of decrease varied by muscle. Strengthening programs should target different muscles, depending on a woman's age and race.

Case-control study of knee osteoarthritis and lifestyle factors considering their interaction with physical workload

AIMS

The aim of this study is to examine the dose-response relationships between age, "lifestyle factors" (body mass index, tobacco smoking, sports), and symptomatic knee osteoarthritis in a population-based case-control study. Additionally, the study aims to investigate the mode of interaction between body mass index (BMI) and physical workload (occupational kneeling/squatting and lifting/carrying of loads) with respect to the risk of symptomatic knee osteoarthritis.

METHODS

In five orthopedic clinics and five practices, 295 male patients aged 25-70 with radiographically confirmed knee osteoarthritis associated with chronic complaints were recruited. The control group comprised 327 male control subjects. In a structured personal interview, body weight at different ages, body height, cumulative amount of smoking, and cumulative duration of different sports activities until the date of first diagnosis of knee osteoarthritis were elicited. Adjusted odds ratios (OR) and 95% confidence intervals (CI) were calculated using unconditional logistic regression analysis. An interaction analysis for the parameters BMI and kneeling/squatting respective lifting/carrying of loads was performed. Population attributable risks (PAR) for knee osteoarthritis were determined for BMI solely and for the combination of BMI with occupational kneeling/squatting and lifting/carrying of loads, respectively.

RESULTS

Age and overweight were strongly associated with the diagnosis of knee osteoarthritis. Compared with persons less than 35 years old, persons who were at least 65 years old had an odds ratio (OR) of 19.0 (95% CI 6.1-58.7) for knee osteoarthritis. Persons with a BMI > or = 28.41 kg/m2 had a strongly elevated risk of knee osteoarthritis (OR 10.8; 95% CI 4.8-24.3) compared to persons with a BMI < 22.86 kg/m2. Heavy tobacco smoking (> or = 55.5 pack years) was associated with a decreased knee osteoarthritis risk in comparison with never-smoking (OR 0.2; 95% CI 0.1-0.5). Ball games (handball, volleyball, basketball) and cycling were associated with symptomatic knee osteoarthritis (OR 4.0; 95% CI 1.8-8.9 and OR 3.7; 95% CI 1.7-7.8 in the highest category of cumulative duration, respectively); to a weaker degree jogging, swimming, and soccer also were positively related to symptomatic knee osteoarthritis. Combining the two parameters, BMI and kneeling/squatting into one variable led to a multiplicative interaction mode for symptomatic knee osteoarthritis. For persons with elevated BMI in combination with moderate to high exposure to occupational kneeling/squatting, the population attributable risk (PAR) was 4%. The PAR for elevated BMI in combination with moderate to high exposure to occupational lifting/carrying of loads was 7%.

CONCLUSIONS

In accordance with the literature, we find a strong association between BMI and knee osteoarthritis risk. Considering the relatively high prevalence of occupational manual materials handling, prevention of knee osteoarthritis should not only focus on body weight reduction, but should also take into account work organizational measures particularly aiming to reduce occupational lifting and carrying of loads.

Gain in adiposity across 15 years is associated with reduced gray matter volume in healthy women

OBJECTIVE

To test whether current gray matter volume (GMV) covaried with previously obtained longitudinal measures of weight gain-as assessed by increases in body mass index (BMI)-among otherwise healthy postmenopausal women. Cross-sectional results indicate that reduced GMV may be associated with excess body weight.

METHODS

Demographic, biometric, and behavioral measures were obtained from 48 women as part of the Pittsburgh Healthy Women Study, a longitudinal epidemiological investigation initiated between 1983 and 1984. In 2005 and 2006, these women took part in a brain imaging protocol.

RESULTS

Premenopausal BMI and a priori chosen confounding variables, including the number of years post menopause, an aggregate measure of perceived life stress spanning a 20-year period, resting blood pressure, total cerebral volume, and severity of white matter hyperintensities (a suspected indicator of aging-related silent cerebrovascular disease), explained approximately 22% of variance in total GMV. An additional 15% of the variance was uniquely explained by the change in BMI between pre- and postmenopausal longitudinal assessments, such that an increase in BMI predicted a greater reduction in GMV.

CONCLUSIONS

An increase in BMI during the menopausal transition and beyond is associated with reduced GMV among otherwise healthy women.