Does obesity affect knee cartilage? A systematic review of magnetic resonance imaging data

Interactions of cumulative load with biomarkers of cartilage turnover predict knee cartilage change over 2 years: data from the osteoarthritis initiative

The purpose was to investigate relationships of cumulative load and cartilage turnover biomarkers with 2-year changes in cartilage in knee osteoarthritis. From participants with Kellgren-Lawrence (KL) grades of 1 to 3, cartilage thickness and transverse relaxation time (T2) were computed from 24-month (baseline) and 48-month magnetic resonance images. Cumulative load was the interaction term of the Physical Activity Scale for the Elderly (PASE) and body mass index (BMI). Serum cartilage oligomeric matrix protein (COMP) and the nitrated form of type II collagen (Coll2-1 NO2) were collected at baseline. Multiple regressions (adjusted for baseline age, KL grade, cartilage measures, pain, comorbidity) evaluated the relationships of cumulative load and biomarkers with 2-year changes. In 406 participants (63.7 (8.7) years), interactions of biomarkers with cumulative load weakly predicted 2-year cartilage changes: (i) COMP × cumulative load explained medial tibia thickness change (R2 increased 0.062 to 0.087, p < 0.001); (ii) Coll2-1 NO2 × cumulative load explained central medial femoral T2 change (R2 increased 0.177 to 0.210, p < 0.001); and (iii) Coll2-1 NO2 × cumulative load explained lateral tibia T2 change (R2 increased 0.166 to 0.188, p < 0.001). Moderate COMP or Coll2-1 NO2 at baseline appeared protective. High COMP or Coll2-1 NO2, particularly with high BMI and low PASE, associated with worsening cartilage. Moderate serum concentrations of cartilage turnover biomarkers, at high and low physical activity, associated with maintained cartilage outcomes over 2 years. In conclusion, high concentrations of cartilage turnover biomarkers, particularly with high BMI and low physical activity, associated with knee cartilage thinning and increasing T2 over 2 years. Key Points • Higher quality cartilage may be better able to tolerate a larger cumulative load than poor quality cartilage. • Among participants enrolled in the Osteoarthritis Initiative Biomarkers Consortium Project, a representation of cumulative load exposure and its interaction with cartilage turnover biomarkers were weakly related with 2-year change in knee cartilage. • These findings suggest that cartilage turnover is a factor that modifies the relationship between loading exposure and cartilage loss in knee OA.

Exploring the pharmacological mechanism of Glycyrrhiza uralensis against KOA through integrating network pharmacology and experimental assessment

Knee osteoarthritis (KOA), a major health and economic problem facing older adults worldwide, is a degenerative joint disease. Glycyrrhiza uralensis Fisch. (GC) plays an integral role in many classic Chinese medicine prescriptions for treating knee osteoarthritis. Still, the role of GC in treating KOA is unclear. To explore the pharmacological mechanism of GC against KOA, UPLC-Q-TOF/MS was conducted to detect the main compounds in GC. The therapeutic effect of GC on DMM-induced osteoarthritic mice was assessed by histomorphology, μCT, behavioural tests, and immunohistochemical staining. Network pharmacology and molecular docking were used to predict the potential targets of GC against KOA. The predicted results were verified by immunohistochemical staining Animal experiments showed that GC had a protective effect on DMM-induced KOA, mainly in the improvement of movement disorders, subchondral bone sclerosis and cartilage damage. A variety of flavonoids and triterpenoids were detected in GC via UPLC-Q-TOF/MS, such as Naringenin. Seven core targets (JUN, MAPK3, MAPK1, AKT1, TP53, RELA and STAT3) and three main pathways (IL-17, NF-κB and TNF signalling pathways) were discovered through network pharmacology analysis that closely related to inflammatory response. Interestingly, molecular docking results showed that the active ingredient Naringenin had a good binding effect on anti-inflammatory-related proteins. In the verification experiment, after the intervention of GC, the expression levels of pp65 and F4/80 inflammatory indicators in the knee joint of KOA model mice were significantly downregulated. GC could improve the inflammatory environment in DMM-induced osteoarthritic mice thus alleviating the physiological structure and dysfunction of the knee joint. GC might play an important role in the treatment of knee osteoarthritis.

Anthropometric measures of obesity in patients with knee joint pathology: Body surface area versus body mass index

BACKGROUND

Obesity is quantified using body mass index. Body surface area may provide a superior and more anthropometric method of quantifying obesity in patients with musculoskeletal knee disease. This study compares the effect of weight, height, age and gender on body mass index and body surface area in a population with orthopaedic knee disease.

METHODS

An observational cohort study was conducted of patients presenting with musculoskeletal knee disease. Associations between body mass index, body surface area, age, gender, height, weight and operative versus non-operative management were analysed.

RESULTS

A total of 151 patients were included. Body surface area was more strongly correlated to weight than body mass index (r = 0.98, p < 0.001 versus r = 0.84, p < 0.001). Body surface area also reflects height which body mass index under presents (r = 0.65, p < 0.001 versus r = -0.08, p = 0.35). Body mass index and body surface area were correlated with one another (r = 0.70, p < 0.001). Age was inversely correlated with body surface area (r = -0.20, p = 0.013) but not body mass index (r = 0.05, p = 0.585). Body mass index did not differ between males and females (30.1 versus 30.9, p = 0.37); however, BSA scores were significantly higher in males than females (2.11 versus 1.91, p < 0.001). Neither body surface area nor body mass index scores influenced operative versus non-operative treatment.

CONCLUSION

Body surface area could be a useful alternative to body mass index when considering obesity in patients with musculoskeletal knee pathology. Body surface area better reflects the effects of height, weight, age and gender than body mass index.

The knee connectome: A novel tool for studying spatiotemporal change in cartilage thickness

Cartilage thickness change is a well-documented biomarker of osteoarthritis pathogenesis. However, there is still much to learn about the spatial and temporal patterns of cartilage thickness change in health and disease. In this study, we develop a novel analysis method for elucidating such patterns using a functional connectivity approach. Descriptive statistics are reported for 1186 knees that did not develop osteoarthritis during the 8 years of observation, which we present as a model of cartilage thickness change related to healthy aging. Within the control population, patterns vary greatly between male and female subjects, while body mass index (BMI) has a more moderate impact. Finally, several differences are shown between knees that did and did not develop osteoarthritis. Some but not all significance appears to be accounted for by differences in sex, BMI, and knee alignment. With this work, we present the connectome as a novel tool for studying spatiotemporal dynamics of tissue change.

Impact of the Body Composition on Knee Osteoarthritis Assessed Using Bioimpedance Analysis

Osteoarthritis (OA) ranks among the most prevalent inflammatory diseases affecting the musculoskeletal system and is a leading cause of disability globally, impacting approximately 250 million individuals. This study aimed to assess the relationship between the severity of knee osteoarthritis (KOA) and body composition in postmenopausal women using bioimpedance analysis (BIA). The study included 58 postmenopausal females who were candidates for total knee arthroplasty. The control group consisted of 25 postmenopausal individuals with no degenerative knee joint changes. The anthropometric analysis encompassed the body mass index (BMI), mid-arm and mid-thigh circumferences (MAC and MTC), and triceps skinfold thickness (TSF). Functional performance was evaluated using the 30 s sit-to-stand test. During the BIA test, electrical parameters such as membrane potential, electrical resistance, capacitive reactance, impedance, and phase angle were measured. Additionally, body composition parameters, including Total Body Water (TBW), Extracellular Water (ECW), Intracellular Water (ICW), Body Cellular Mass (BCM), Extracellular Mass (ECM), Fat-Free Mass (FFM), and Fat Mass (FM), were examined. The study did not find any statistically significant differences in the electrical parameters between the control (0-1 grade on the K-L scale) and study groups (3-4 grade on the K-L scale). However, statistically significant differences were observed in BMI, fat mass (FM), arm circumference, triceps skinfold thickness, and sit-to-stand test results between the analyzed groups. In conclusion, the association between overweight and obesity with KOA in postmenopausal women appears to be primarily related to the level of adipose tissue and its metabolic activity.

Metabolic obesity and the risk of knee osteoarthritis progression in elderly community residents: A 3-year longitudinal cohort study

OBJECTIVE

Metabolic syndrome is a major health problem worldwide associated with obesity, thus drawing attention to its relation to osteoarthritis (OA). However, it is still uncertain whether metabolic syndrome or body fat distribution is associated with knee OA. The aim of this longitudinal study was to elucidate the association between metabolic obesity and adverse structural changes of knee OA assessed by magnetic resonance imaging (MRI).

METHODS

Participants were recruited from the Hallym Aging Study cohort in Korea. Knee MRI scans, along with dual-energy X-ray absorptiometry, were assessed in 226 participants at baseline and after 3 years. The structural progression in the tibiofemoral joint was evaluated using the semi-quantitative Whole-Organ MRI Score (WORMS) for cartilage morphology and bone marrow lesions (BML). Logistic regression with generalized estimating equation was performed for associations of metabolic risk factors with worsening of WORMS scores at the subregional level.

RESULTS

In the medial compartment, fat mass in women was associated with cartilage loss, but the statistical significance disappeared after adjusting for body mass index. Metabolic syndrome and each of its components were not associated with cartilage loss or increase of BML. On the other hand, the interaction effects of metabolic syndrome on the association between obesity and knee OA progression were not significant.

CONCLUSION

In this cohort, metabolic effects of obesity on knee cartilage damage and BML were not demonstrated. Further large-scale studies are required to prove the causal relationship between metabolic obesity and knee OA.

Daily cumulative load and body mass index alter knee cartilage response to running in women

BACKGROUND

It is unknown whether a greater accumulation of knee load over a typical day is related to how cartilage responds to an acute bout of loading. This information may clarify the role of habitual activity on cartilage function.

RESEARCH QUESTION

Is there a relationship between change in tibial and femoral cartilage thickness, volume, and T2 relaxation time following running with daily cumulative knee load in women? Secondarily, is there a relationship between cartilage change following running and the statistical interaction of body mass index (BMI) and daily steps?

METHODS

Participants (n = 15) completed gait analyses and wore an accelerometer over a week. Daily cumulative knee load was the statistical interaction between tibial compressive joint reaction force (JRF) impulse with the average number of daily steps measured using accelerometry. Magnetic resonance imaging scans were acquired before and immediately after 15-min of treadmill running. Changes in tibial and femoral cartilage thickness, volume, and T2 relaxation time were calculated. Multiple linear regressions tested the associations of cartilage change outcomes with: baseline (thickness, volume, T2), JRF impulse, steps, and the interaction JRF impulse*steps. Secondarily, BMI was substituted for JRF impulse.

RESULTS AND SIGNIFICANCE

Tibial volume change was explained by baseline volume, JRF impulse, steps, and JRF impulse*steps (R² = 0.50, p = 0.013). Additionally, tibial volume change was explained by baseline volume, BMI, steps, and BMI*steps (R² = 0.43, p = 0.002). Those who were more physically active with lower JRF impulse (or lower BMI) showed less change in tibial cartilage after a running exposure. This may suggest cartilage conditioning.

Mean femoral cartilage thickness is higher in athletes as compared with sedentary individuals

PURPOSE

It is unclear how high-intensity physical activity (HIPA) affects the knee joint, specifically the femoral cartilage (FC). Therefore, the aims of this study were to evaluate FC thickness via ultrasound among elite athletes involved in different types of HIPA, and to determine whether there is a correlation between serum cartilage oligomeric matrix protein (sCOMP) and rectus femoris (RF) thickness.

METHOD

A total of 132 male individuals participated in this study and were assigned to two groups, the sedentary (n = 43, 23.9 ± 3.7) and athlete groups (n = 89, 22.7 ± 4.6), which did not significantly differ in age. The athletes were elite and performed HIPA during sports such as volleyball (n = 20), soccer (n = 21), basketball (n = 28), and weightlifting (n = 20). RF thickness and three (mid-point) measurements were obtained for each knee. The mean FC thickness for each knee was defined as the sum of the medial, lateral condyles, and intercondylar areas. Blood samples for sCOMP analyses were also obtained.

RESULTS

All the measurements of the FC of both knees were significantly higher in the athletes than in the sedentary individuals (p < 0.001 and p = 0.001). The mean right and left FC values were also higher in the athletes (p < 0.001). Multiple linear regression analysis showed that participation in sporting activities was a significant predictor associated with the right and left mean FC thickness (p < 0.001 for both). No significant differences in the sCOMP levels were found between the two groups.

CONCLUSION

It was found that the mean FC was higher among athletes than among sedentary individuals. As a result, it is suggested that sports' participation is an independent factor associated with the right and left mean FC thickness.

LEVEL OF EVIDENCE

III.

Ultrasound measurement of femoral cartilage thickness in the knee of healthy young university students

BACKGROUND AND OBJECTIVE

Articular cartilage (AC) is always affected in any joint with osteoarthritis. Ultrasound can be a useful tool in monitoring changes in the AC. The purpose of the present study is to ultrasound measure the thickness of the AC in the distal femur in young students and determine its relationship with body mass index (BMI), muscle mass, body fat and sports practice.

MATERIALS AND METHODS

An observational cross-sectional study was conducted with healthy volunteers, between 15 and 25 years old. Anthropometric data were collected and the thickness of the femoral cartilage of the knee was measured at 5 points. In addition, the percentage of muscle and body fat was measured in a subgroup.

RESULTS

100 subjects were included in the study. The average age was 20 years (± 2.5). The average BMI was 23 kg/m² (± 3.1). AC was thicker in men and sportsmen, versus women and sedentary people, with a statistically significant difference. When comparing BMI with AC thickness no significant relationship was found; however, only 2 participants had BMI > 30.

CONCLUSIONS

Cartilage thickness has a direct relationship with the percentage of muscle, and inversely with the percentage of fat. BMI is not a good parameter when evaluating the dynamic behaviour of cartilage in non-obese youths.

Association of body composition, physical activity and physical performance with knee cartilage thickness and bone area in young adults

OBJECTIVE

To describe associations of body composition, physical activity and physical performance with knee cartilage thickness and subchondral bone area in young adults.

METHODS

Body composition, physical activity and physical performance were measured 4-5 years prior to knee MRI. Cartilage thickness and bone area were measured quantitatively from MRI. Associations were assessed using linear regression analysis, with mediators being identified using mediation analysis.

RESULTS

Participants (n = 186) were 31-41 years of age when the MRI was acquired and 48% were female. Greater lean mass was positively associated with cartilage thickness [β = 6.52 μm/kg (95% CI 0.86, 12.18)] and bone area [β = 13.37 mm2/kg (95% CI 5.43, 21.31)]. Physical performance measures were positively associated with cartilage thickness [long jump: β = 2.44 μm/cm (95% CI 0.70, 4.18); hand grip strength: 7.74 μm/kg (95% CI 1.50, 13.98); physical work capacity: 1.07 μm/W (95% CI 0.29, 1.85)] and bone area [long jump: β = 3.99 mm2/cm (95% CI 0.64, 7.34); hand grip strength: 19.06 mm2/kg (95% CI 7.21, 30.92); leg strength: 3.18 mm2/kg (95% CI 1.09, 5.28); physical work capacity: 3.15 mm2/W (95% CI 1.70, 4.60)]. Mediation analysis suggested these associations were mediated by lean mass (effect mediated: 27-95%).

CONCLUSION

Greater lean mass and better physical performance measured 4-5 years prior were associated with greater knee cartilage thickness and subchondral bone area in young adults, and the associations of physical performance were largely mediated by lean mass. These findings suggest lean mass may play an important role in maintaining knee joint health in young adults.

Using Cumulative Load to Explain How Body Mass Index and Daily Walking Relate to Worsening Knee Cartilage Damage Over Two Years: The MOST Study

OBJECTIVE

Knee cartilage damage is often linked to mechanical overloading. However, cartilage requires mechanical load to remain healthy, suggesting that underloading may be detrimental. This study was undertaken to examine knee overloading and underloading by defining cumulative load as the joint effects of body mass index (BMI) and daily walking, and examine the relationship between cumulative load and worsening cartilage damage over 2 years.

METHODS

We used data from the Multicenter Osteoarthritis Study. Steps/day, measured by accelerometry, and BMI were calculated at the 60-month visit. Cartilage damage on magnetic resonance imaging was semiquantitatively scored using the Whole-Organ Magnetic Resonance Imaging Score (WORMS) at the 60-month and 84-month visits; worsening damage was defined as increased WORMS between visits. Risk ratios (RRs) and 95% confidence intervals (95% CIs) were calculated using binomial regression, with adjustment for potential confounders.

RESULTS

Our study included 964 participants, 62% of whom were female, with a mean ± SD age of 66.9 ± 7.5 years. Participants had a mean ± SD BMI of 29.7 ± 4.8 kg/m² and walked a mean ± SD of 7,153 ± 2,591 steps/day. Participants who walked a moderate number of steps/day (6,000-7,900) or a high number of steps/day (>7,900) and had a high BMI (>31 kg/m² ) had a greater risk of worsening medial tibiofemoral (TF) damage (RR 2.83 [95% CI 1.46-5.48] and RR 2.61 [95% CI 1.50-4.54], respectively) compared with those who walked similar steps/day and had a low BMI (18-27 kg/m² ). Participants with a low number of steps/day (<6,000) and a low BMI had a greater risk of worsening medial TF and lateral patellofemoral (PF) damage (RR 2.03 [95% CI 1.06-3.92] and RR 2.28 [95% CI 1.06-4.85], respectively) compared with those who walked a high number of steps/day and had a low BMI. Effect estimates for other compartments of the knee did not reach statistical significance.

CONCLUSION

This study provides preliminary evidence that both overloading and underloading may be detrimental to medial TF cartilage, and underloading may be detrimental to lateral PF cartilage.

Association of trajectory of body mass index with knee pain risk in Japanese middle-aged women in a prospective cohort study: the Japan Nurses' Health Study

OBJECTIVES

To investigate whether body mass index (BMI) trajectory, lifestyle and reproductive factors are associated with knee pain risk among middle-aged women.

DESIGN

Prospective study of the Japan Nurses' Health Study (JNHS).

SETTING

The JNHS investigates the health of female nurses in Japan. Biennial follow-up questionnaires are mailed to the participants.

PARTICIPANTS

The 7434 women aged over 40 years who responded to the 10-year self-administered follow-up questionnaire.

PRIMARY OUTCOME MEASURE

Self-reported knee pain at the 10-year follow-up was the primary outcome. We analysed BMI (normal or overweight) trajectory data from a baseline survey to the 10-year follow-up survey using group-based trajectory modelling. Exposure measurements were BMI trajectory, BMI at age 18 years, lifestyle variables and reproductive history.

RESULTS

BMI trajectories from baseline to the 10-year follow-up were divided into four groups: remained normal, remained overweight, gained weight or lost weight. At the 10-year follow-up, 1281 women (17.2%) reported knee pain. Multivariable logistic regression analysis revealed that compared with the remained normal group, multivariable-adjusted ORs (95% CI) of knee pain were 1.93 (1.60 to 2.33) for the remained overweight group, 1.60 (1.23 to 2.08) for the gained weight group and 1.40 (0.88 to 2.21) for the lost weight group. The attributable risk percent (95% CI) of the remained overweight group was 48.1% (37.3% to 57.0%) compared with the reference group of remained normal. Alcohol intake at baseline was significantly associated with knee pain.

CONCLUSIONS

The lost weight group had a lower risk than the remained overweight group and the gained weight group and did not carry statistically significant risks for knee pain. Weight reduction and maintaining a normal BMI in middle age was important for preventing knee pain in women.

Association of age, sex and BMI with the rate of change in tibial cartilage volume: a 10.7-year longitudinal cohort study

Background

To describe the association of age, sex and body mass index with the rate of change of tibial knee cartilage volume over 10.7 years in a community-based sample of older adults.

Methods

Four hundred and eighty-one participants (49% female, mean age 60.8 years [range 51.1–79.7], 49% had knee pain and 58% radiographic osteoarthritis) were included. Tibial cartilage volume of the right knee was assessed on T1-weighted fat-suppressed 1.5 T MRI at baseline and 10.7 years. Data analyses were performed using linear regression models.

Results

The average rate of loss of cartilage volume was 1.2%/year (range 0.2–3.9%) with all participants losing cartilage volume over the study period. There was a significant association between age and loss of tibial cartilage volume in the medial (0.023%/year, 95% confidence interval [CI] 0.010 to 0.036%, p < 0.001), lateral (0.013%/year, 95% CI 0.003 to 0.023%, p = 0.012) and total tibia (0.018%/year, 95% CI 0.009 to 0.026%, p < 0.001). Higher body mass index at baseline and increases in body mass index over time were associated with a greater tibial cartilage loss at the medial (body mass index at baseline 0.040%/year, 95% CI 0.022 to 0.058%, p < 0.001; increases in body mass index 0.055%/year, 95% CI 0.018 to 0.093%, p = 0.004) but not lateral compartment. No evidence of non-linear relationships was observed. Compared to males, females lost more lateral tibial cartilage with increasing age (0.023%/year, 95% CI 0.003 to 0.043%, p = 0.024 for interaction).

Conclusions

Tibial cartilage volume declines at a faster rate with increasing age and body mass index in both males and females, particularly in the medial compartment. In contrast to the low rate of change in radiographs, our findings suggest that cartilage loss at the tibia is universal in this age group.

Correlation of Body Mass Index with Pelvis and Lumbar Spine Alignment in Sagittal Plane in Hemophilia Patients

Introduction: Concern about weight gain among people has been high due to negative health consequences in addition to the increasing prevalence of the problem. Overweight and obesity also occur in patients with hemophilia. Analysis of literature shows that increased body weight might have a biomechanical effect on the spatial orientation of the pelvis and the lumbar spine. The aim of this study was to determine the correlation between body mass index (BMI) and the parameters characterizing the alignment of the sacrum (SS, sacral slope), the pelvis (PT, pelvic tilt; PI, pelvic incidence) and the angle value of lumbar lordosis (LL, lumbar lordosis) assessed in the sagittal plane among patients with hemophilia. Materials and methods: A total of 49 patients were subjected to the study, 23 of whom met the inclusion criteria. Body weight and height were measured. Measurement of the angle values of indicators characterizing the position of the lumbar–pelvic complex was established based on X-ray imaging analysis. Results: Analysis of the correlation between the BMI and sacral, pelvic, and lumbar indicators evaluated in the sagittal plane in the study group of patients with hemophilia showed a correlation between BMI and SS (r = 0.48). SS values were significantly and positively related to PI (r = 0.6; p = 0.002) and LL (r = 0.46; p = 0.02). The results obtained indicate the BMI relationship with the setting of the sacrum in the sagittal plane (SS). After adjusting for the knee flexion contracture, the correlation on the border of significance (b = 0.73, p = 0.07) between the body mass index and the spatial orientation of the pelvis and the spine was revealed. Conclusion: We hypothesize that increased body weight among people with hemophilia might have an effect on the positioning of the lumbosacral region. Therefore, it is believed that preventing obesity among people with hemophilia can contribute to a smaller number of intra-articular hemorrhages and better orthopedic condition of the limb joints, and thus could avoid changes in the lumbosacral region as well as their consequences.

Establishing outcome measures in early knee osteoarthritis

The classification and monitoring of individuals with early knee osteoarthritis (OA) are important considerations for the design and evaluation of therapeutic interventions and require the identification of appropriate outcome measures. Potential outcome domains to assess for early OA include patient-reported outcomes (such as pain, function and quality of life), features of clinical examination (such as joint line tenderness and crepitus), objective measures of physical function, levels of physical activity, features of imaging modalities (such as of magnetic resonance imaging) and biochemical markers in body fluid. Patient characteristics such as adiposity and biomechanics of the knee could also have relevance to the assessment of early OA. Importantly, research is needed to enable the selection of outcome measures that are feasible, reliable and validated in individuals at risk of knee OA or with early knee OA. In this Perspectives article, potential outcome measures for early symptomatic knee OA are discussed, including those measures that could be of use in clinical practice and/or the research setting.

Microarray analysis of the molecular mechanisms associated with age and body mass index in human meniscal injury

The aim of the present study was to identify genes and functional pathways associated with meniscal injuries affected by age or body mass index (BMI) using microarray analysis. The GSE45233 gene expression dataset with 12 injured meniscus samples associated with age and BMI and GSE66635 dataset with 12 injured and 12 normal meniscus samples were downloaded from the Gene Expression Omnibus database. Differentially expressed genes (DEGs) were identified based on age or BMI in GSE45233. DEGs between injured and normal meniscus samples in GSE66635 were also identified. Common DEGs between GSE45233 and GSE66635 were identified as feature genes associated with age or BMI, followed by protein-protein interaction (PPI) network and functional pathway enrichment analyses for the feature genes. Finally, the GSE51588 genome-wide expression profile was then downloaded from the GEO database to validate the results. A total of 1,328 DEGs were identified. Of these, 28 age-associated and 20 BMI-associated meniscal injury genes were obtained. B-cell lymphoma-2 (Bcl-2) and matrix metalloproteinase-14 were identified as hub genes in the PPI networks. Functional pathway enrichment analysis revealed that vascular endothelial growth factor A (VEGFA), transferrin (TF) and Bcl-2 were involved in the hypoxia-inducible factor 1 signaling pathway. TF was involved in the mineral absorption function pathway associated with BMI. Additionally, TF and VEGFA were identified to be overlapping candidate genes of GSE45233 and GSE66635, and DEGs in GSE51588. Therefore, VEGFA, TF, and Bcl-2 may be important genes for human meniscal injuries. Additional evaluations of these results are required.

Association of adiposity measures in childhood and adulthood with knee cartilage thickness, volume and bone area in young adults

OBJECTIVE

To describe the associations of childhood and adulthood adiposity measures with knee cartilage thickness, volume and bone area in young adults.

METHODS

Childhood and adulthood adiposity measures (weight, height, waist circumference and hip circumference) of 186 participants were collected in 1985 (aged 7-15 years) and during 2004-2006 (aged 26-36 years). Knee magnetic resonance imaging was conducted during 2008-2010 (aged 31-41 years) and cartilage thickness, volume and bone area were measured using a quantitative approach (Chondrometrics, Germany). Linear regressions were used to examine the above associations.

RESULTS

The prevalence of overweight was 7.6% in childhood and 42.1% in adulthood. Childhood weight (β = - 5.57 mm²/kg) and body mass index (BMI) (β = - 11.55 mm²/kg/m²) were negatively associated with adult patellar bone area, whereas adult weight was positively associated with bone area in medial femorotibial compartment (MFTC) (β = 3.37 mm²/kg) and lateral femorotibial compartment (LFTC) (β = 2.08 mm²/kg). Adult waist-hip ratio (WHR) was negatively associated with cartilage thickness (MFTC: β = - 0.011; LFTC: β = - 0.012 mm/0.01 unit), volume (Patella: β = - 20.97; LFTC: β = - 21.71 mm³/0.01 unit) and bone area (Patella: β = - 4.39 mm²/0.01 unit). The change in WHR z-scores from childhood to adulthood was negatively associated with cartilage thickness (MFTC: β = - 0.056 mm), volume (patella: - 89.95; LFTC: - 93.98 mm³), and bone area (patella: - 20.74 mm²). All p-values < 0.05.

CONCLUSIONS

Childhood weight and BMI were negatively but adult weight was positively associated with adult bone area. Adult WHR and the change in WHR from childhood to adulthood were negatively associated with cartilage thickness, volume, and bone area. These suggest early-life adiposity measures may affect knee structures in young adults.

Association of childhood adiposity measures with adulthood knee cartilage defects and bone marrow lesions: a 25-year cohort study

OBJECTIVE

To describe the associations between childhood adiposity measures and adulthood knee cartilage defects and bone marrow lesions (BMLs) measured 25 years later.

METHODS

327 participants from the Australian Schools Health and Fitness Survey (ASHFS) of 1985 (aged 7-15 years) were followed up 25 years later (aged 31-41 years). Childhood measures (weight, height and skinfolds) were collected in 1985. Body mass index (BMI), overweight status and fat mass were calculated. Participants underwent 1.5 T knee magnetic resonance imaging (MRI) during 2008-2010, and cartilage defects and BMLs were scored from knee MRI scans. Log binomial regressions were used to examine the associations.

RESULTS

Among 327 participants (47.1% females), 21 (6.4%) were overweight in childhood. Childhood adiposity measures were associated with the increased risk of adulthood patellar cartilage defects (Weight relative risk (RR) 1.05/kg, 95% confidence interval (CI) 1.01-1.09; BMI 1.10/kg/m², 1.01-1.19; Overweight 2.22/yes, 1.21-4.08; fat mass 1.11/kg, 1.01-1.22), but not tibiofemoral cartilage defects. Childhood adiposity measures were not significantly associated with adulthood knee BMLs except for the association between childhood overweight status and adulthood patellar BMLs (RR 2.87/yes, 95% CI 1.10-7.53). These significant associations persisted after adjustment for corresponding adulthood adiposity measure.

CONCLUSION

Childhood adiposity measures were associated with the increased risk of adulthood patellar cartilage defects and, to a lesser extent, BMLs, independent of adulthood adiposity measures. These results suggest that adiposity in childhood has long-term effects on patellar structural abnormalities in young adults.

Autologous chondrocyte implantation in the knee: systematic review and economic evaluation

BACKGROUND

The surfaces of the bones in the knee are covered with articular cartilage, a rubber-like substance that is very smooth, allowing frictionless movement in the joint and acting as a shock absorber. The cells that form the cartilage are called chondrocytes. Natural cartilage is called hyaline cartilage. Articular cartilage has very little capacity for self-repair, so damage may be permanent. Various methods have been used to try to repair cartilage. Autologous chondrocyte implantation (ACI) involves laboratory culture of cartilage-producing cells from the knee and then implanting them into the chondral defect.

OBJECTIVE

To assess the clinical effectiveness and cost-effectiveness of ACI in chondral defects in the knee, compared with microfracture (MF).

DATA SOURCES

A broad search was done in MEDLINE, EMBASE, The Cochrane Library, NHS Economic Evaluation Database and Web of Science, for studies published since the last Health Technology Assessment review.

REVIEW METHODS

Systematic review of recent reviews, trials, long-term observational studies and economic evaluations of the use of ACI and MF for repairing symptomatic articular cartilage defects of the knee. A new economic model was constructed. Submissions from two manufacturers and the ACTIVE (Autologous Chondrocyte Transplantation/Implantation Versus Existing Treatment) trial group were reviewed. Survival analysis was based on long-term observational studies.

RESULTS

Four randomised controlled trials (RCTs) published since the last appraisal provided evidence on the efficacy of ACI. The SUMMIT (Superiority of Matrix-induced autologous chondrocyte implant versus Microfracture for Treatment of symptomatic articular cartilage defects) trial compared matrix-applied chondrocyte implantation (MACI^®) against MF. The TIG/ACT/01/2000 (TIG/ACT) trial compared ACI with characterised chondrocytes against MF. The ACTIVE trial compared several forms of ACI against standard treatments, mainly MF. In the SUMMIT trial, improvements in knee injury and osteoarthritis outcome scores (KOOSs), and the proportion of responders, were greater in the MACI group than in the MF group. In the TIG/ACT trial there was improvement in the KOOS at 60 months, but no difference between ACI and MF overall. Patients with onset of symptoms < 3 years' duration did better with ACI. Results from ACTIVE have not yet been published. Survival analysis suggests that long-term results are better with ACI than with MF. Economic modelling suggested that ACI was cost-effective compared with MF across a range of scenarios.

LIMITATIONS

The main limitation is the lack of RCT data beyond 5 years of follow-up. A second is that the techniques of ACI are evolving, so long-term data come from trials using forms of ACI that are now superseded. In the modelling, we therefore assumed that durability of cartilage repair as seen in studies of older forms of ACI could be applied in modelling of newer forms. A third is that the high list prices of chondrocytes are reduced by confidential discounting. The main research needs are for longer-term follow-up and for trials of the next generation of ACI.

CONCLUSIONS

The evidence base for ACI has improved since the last appraisal by the National Institute for Health and Care Excellence. In most analyses, the incremental cost-effectiveness ratios for ACI compared with MF appear to be within a range usually considered acceptable. Research is needed into long-term results of new forms of ACI.

STUDY REGISTRATION

This study is registered as PROSPERO CRD42014013083.

FUNDING

The National Institute for Health Research Health Technology Assessment programme.

Relative and absolute test-retest reliabilities of biomechanical risk factors for knee osteoarthritis progression: benchmarks for meaningful change

OBJECTIVE

Biomechanical factors are important treatment targets in knee osteoarthritis. The knee adduction (KAM) and flexion (KFM) moments, quadriceps strength and power, load frequency, and body mass index (BMI) all have the potential to affect knee articular cartilage integrity by modulating forces across the joint. To identify clinically meaningful change, however, these measurements must be reliable and sensitive to change. This study estimated relative and absolute test-retest reliabilities over long periods of biomechanical risk factors for knee osteoarthritis progression.

METHOD

Data from a longitudinal, observational study were analyzed for knee osteoarthritis patients with data at baseline, 6-month and 24-month follow-ups. Gait kinematics and kinetics, quadriceps strength and power, daily load frequency and BMI were collected. Relative and absolute test-retest reliabilities of these measures were estimated using intraclass correlation coefficients (ICCs) and standard errors of measurement (SEMs), respectively. Minimal detectable change at the 95% confidence level (MDC95) was also calculated.

RESULTS

Data from 46 participants [36 women; age 61.0 (6.6) years] were included. Good-to-excellent relative reliabilities (ICC ≥ 0.80) indicated that KAM peak and impulse, quadriceps strength and power, and BMI had a strong ability to discriminate amongst participants. Absolute reliabilities were high for quadriceps strength and BMI, which demonstrated reasonable within-participant variability (SEMs ≤ 11% of the mean). The MDC95 values supported use of clinical interventions effective in reducing BMI and KAM, and increasing quadriceps strength.

CONCLUSION

These data are useful in interpreting findings from interventional or longitudinal investigations by determining whether observed changes are beyond measurement error and interpretable as true change.

Association of body mass index with knee cartilage damage in an asymptomatic population-based study

Background

Cartilage changes are an important early finding of osteoarthritis (OA), which can exist even before symptoms. Our objective was to determine the prevalence of knee cartilage damage on magnetic resonance imaging (MRI) in an asymptomatic population-based cross-sectional study and to evaluate the association of body mass index (BMI) with cartilage damage.

Methods

Subjects, aged 40-79 years, without knee pain (n = 73) were recruited as a random population sample and assessed for BMI (kg/m²), including current BMI (measured), past BMI at age 25 (self-reported) and change in BMI. Knee cartilage was scored semi-quantitatively (grades 0-4) on MRI. In primary analysis, cartilage damage was defined as ≥2 (at least moderate) and in a secondary analysis as ≥3 (severe). We also conducted a sensitivity analysis by dichotomizing current BMI as <25 vs. ≥25. Logistic regression was used to evaluate the association of each BMI variable with prevalent MRI-detected cartilage damage, adjusted for age and sex.

Results

Of 73 subjects, knee cartilage damage ≥2 and ≥3 was present in 65.4% and 28.7%, respectively. The median current BMI was 26.1, median past BMI 21.6, and median change in BMI was a gain of 2.8. For cartilage damage ≥2, current BMI had a non-statistically significant OR of 1.65 per 5 units (95% CI 0.93-2.92). For cartilage damage ≥3, current BMI showed a trend towards statistical significance with an OR of 1.70 per 5 units (95% CI 0.99-2.92). Past BMI and change in BMI were not significantly associated with cartilage damage. Current BMI ≥ 25 was statistically significantly associated with cartilage damage ≥2 (OR 3.04 (95% CI 1.10-8.42)), but not for ≥3 (OR 2.63 (95% CI 0.86-8.03)).

Conclusions

MRI-detected knee cartilage damage was highly prevalent in this asymptomatic population-based cohort. We report a trend towards significance of BMI with cartilage damage severity. Subjects with abnormal current BMI (≥25) had a 3-fold increased odds of cartilage damage ≥2, compared to those with normal BMI. This study lends support towards the role of obesity in the pathogenesis of knee cartilage damage at an asymptomatic stage of disease.

Baseline knee adduction moment interacts with body mass index to predict loss of medial tibial cartilage volume over 2.5 years in knee Osteoarthritis

This study aimed to determine the extent to which changes over 2.5 years in medial knee cartilage thickness and volume were predicted by: (1) Peak values of the knee adduction (KAM) and flexion moments; and (2) KAM impulse and loading frequency, representing cumulative load, after controlling for age, sex and body mass index (BMI). Adults with clinical knee osteoarthritis participated. At baseline and approximately 2.5 years follow-up, cartilage thickness and volume of the medial tibia and femur were segmented from magnetic resonance imaging scans. Gait kinematics and kinetics, and daily knee loading frequency were also collected at baseline. Multiple linear regressions predicted changes in cartilage morphology from baseline gait mechanics. Data were collected from 52 participants (41 women) [age 61.0 (6.9) y; BMI 28.5 (5.7) kg/m² ] over 2.56 (0.51) years. There were significant KAM peak-by-BMI (p = 0.023) and KAM impulse-by-BMI (p = 0.034) interactions, which revealed that larger joint loads in those with higher BMIs were associated with greater loss of medial tibial cartilage volume. In conclusion, with adjustments for age, sex, and cartilage measurement at baseline, large magnitude KAM peak and KAM impulse each interacted with BMI to predict loss of cartilage volume of the medial tibia over 2.5 years among individuals with knee osteoarthritis. These data suggest that, in clinical knee osteoarthritis, exposure to large KAMs may be detrimental to cartilage in those with larger BMIs. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:2476-2483, 2017.

How Are Obesity and Body Composition Related to Patellar Cartilage? A Systematic Review

Objective.

The aim of this review was to systematically examine the evidence for an association between measures of obesity [weight and body mass index (BMI)] and body composition (fat mass and fat-free mass) and patellar cartilage, assessed using magnetic resonance imaging.

Methods.

Three electronic databases (MEDLINE, EMBASE, and CINAHL) were searched up to April 2016 using full text and MeSH terms to identify studies examining the associations between obesity and body composition, and patellar cartilage. Two independent reviewers extracted the data and assessed the methodological quality of included studies.

Results.

Seventeen studies were included: 5 cross-sectional, 10 cohort studies measuring outcomes at 2 timepoints, and 2 longitudinal studies assessing outcome only at the timepoint. Eleven studies were of high or moderate quality. In asymptomatic middle-aged adults, elevated body weight and BMI were systematically associated with worse patellofemoral cartilage scores. There was more consistent evidence for patellar cartilage defects than patellar cartilage volume, particularly in women. Increased BMI was also consistently associated with increased cartilage loss in longitudinal studies, although not all attained statistical significance.

Conclusion.

There is a need for more high-quality research to confirm these findings and to better explain the relative contributions of metabolic and biomechanical factors to the initiation of patellofemoral osteoarthritis, to devise effective strategies to manage this common and disabling condition.

Association Between Pain at Sites Outside the Knee and Knee Cartilage Volume Loss in Elderly People Without Knee Osteoarthritis: A Prospective Study

OBJECTIVE

Pain is common in the elderly. Knee pain may predict knee cartilage loss, but whether generalized pain is associated with knee cartilage loss is unclear. This study, therefore, aimed to determine whether pain at multiple sites predicts knee cartilage volume loss among community-dwelling older adults, and, if so, to explore potential mechanisms.

METHODS

Data from the prospective Tasmanian Older Adult Cohort study was utilized (n = 394, mean age 63 years, range 52-79 years). Experience of pain at multiple sites was assessed using a questionnaire at baseline. T1-weighted fat-saturated magnetic resonance imaging of the right knee was performed to assess the cartilage volume at baseline and after 2.6 years. Linear regression modeling was used with adjustment for potential confounders.

RESULTS

The median number of painful sites was 3 (range 0-7). There was a dose-response relationship between the number of painful sites and knee cartilage volume loss in the lateral and total tibiofemoral compartments (lateral β = -0.28% per annum; total β = -0.25% per annum, both P for trend < 0.05), but not in the medial compartment. These associations were stronger in participants without radiographic knee osteoarthritis (OA) (P < 0.05) and independent of age, sex, body mass index, physical activity, pain medication, and knee structural abnormalities.

CONCLUSION

The number of painful sites independently predicts knee cartilage volume loss, especially in people without knee OA, suggesting that widespread pain may be an early marker of more rapid knee cartilage loss in those without radiographic knee OA. The underlying mechanism is unclear, but it is independent of anthropometrics, physical activity, and knee structural abnormalities.

The interaction between weight and family history of total knee replacement with knee cartilage: a 10-year prospective study

OBJECTIVE

Although being overweight or obese is an important risk factor for the development of knee osteoarthritis (OA), the interplay between weight and genetic factors remains unclear. This study aimed to examine the associations between weight and knee cartilage volume/defects over 10 years in offspring having at least one parent with a total knee replacement (TKR) for primary knee OA and in controls without a knee OA family history.

METHOD

367 participants (183 offspring and 184 controls) aged from 26 to 61 years were recruited at baseline, and followed at 2 and 10 years later. T1-weighted magnetic resonance imaging (MRI) of the right knee was used to measure cartilage volume/defects at each time-point. Mixed-effects models were used with adjustment for potential confounders.

RESULTS

Study participants were middle-age adults (mean age 45 years, mean weight 77.5 kg at baseline). In multivariable analysis, increasing body weight was deleteriously associated with medial tibiofemoral cartilage volume (β = -0.28 ml, per 1 SD increase, 95% CI -0.49 to -0.07) and presence of medial tibiofemoral cartilage defects (RR = 1.27, per 1 SD increase, 95% CI 1.07 to 1.51) in offspring over 10 years. Similar associations were observed for lateral tibiofemoral cartilage volume (β = -0.19 ml, P = 0.059), and defects (RR = 1.24, P = 0.049). However, there were no statistically significant associations between weight and cartilage volume or defects in controls.

CONCLUSION

The adverse effects of increasing weight are stronger in the offspring of people with knee replacement for knee OA suggesting genetics-environment interaction with regard to overweight/obesity in the pathogenesis of knee OA particularly in the early stages.

Obesity and Knee Arthroscopy – a Review

Obesity is currently a global epidemic, often referred to as “globesity”, impacting the life of millions worldwide. A risk factor for many diseases, obesity can also be linked to developing intra-articular lesions of the knee, affecting the menisci, ligaments and cartilage. Furthermore, obesity has been shown to influence the outcome of surgical interventions, including those of the musculoskeletal system. Although many studies addressed the relationship of obesity and joint replacement, articles relating to arthroscopy and obesity, and knee arthroscopy in particular, are a bit scarcer. The majority of data suggest that an increase in BMI leads to a similar increase in the rates of intra- and postoperative complications, and most authors agree that a higher body mass index can influence both the procedure itself and its outcomes, including the subjective results reported by the patients. Still, some studies show different results, especially in patients that are overweight or with low-grade obesity, where the outcomes are comparable to those of the non-obese population. Thus, it can be concluded that obesity is an important patient characteristic that needs to be taken into consideration when planning, performing, and assessing the results of knee arthroscopy.

RNA Microarray Analysis of Macroscopically Normal Articular Cartilage from Knees Undergoing Partial Medial Meniscectomy: Potential Prediction of the Risk for Developing Osteoarthritis

Objectives

(i) To provide baseline knowledge of gene expression in macroscopically normal articular cartilage, (ii) to test the hypothesis that age, body-mass-index (BMI), and sex are associated with cartilage RNA transcriptome, and (iii) to predict individuals at potential risk for developing “pre-osteoarthritis” (OA) based on screening of genetic risk-alleles associated with OA and gene transcripts differentially expressed between normal and OA cartilage.

Design

Healthy-appearing cartilage was obtained from the medial femoral notch of 12 knees with a meniscus tear undergoing arthroscopic partial meniscectomy. Cartilage had no radiographic, magnetic-resonance-imaging or arthroscopic evidence for degeneration. RNA was subjected to Affymetrix microarrays followed by validation of selected transcripts by microfluidic digital polymerase-chain-reaction. The underlying biological processes were explored computationally. Transcriptome-wide gene expression was probed for association with known OA genetic risk-alleles assembled from published literature and for comparison with gene transcripts differentially expressed between healthy and OA cartilage from other studies.

Results

We generated a list of 27,641 gene transcripts in healthy cartilage. Several gene transcripts representing numerous biological processes were correlated with age and BMI and differentially expressed by sex. Based on disease-specific Ingenuity Pathways Analysis, gene transcripts associated with aging were enriched for bone/cartilage disease while the gene expression profile associated with BMI was enriched for growth-plate calcification and OA. When segregated by genetic risk-alleles, two clusters of study patients emerged, one cluster containing transcripts predicted by risk studies. When segregated by OA-associated gene transcripts, three clusters of study patients emerged, one of which is remarkably similar to gene expression pattern in OA.

Conclusions

Our study provides a list of gene transcripts in healthy-appearing cartilage. Preliminary analysis into groupings based on OA risk-alleles and OA-associated gene transcripts reveals a subset of patients expressing OA transcripts. Prospective studies in larger cohorts are needed to assess whether these patterns are predictive for OA.

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.

What is the role of lifestyle behaviour change associated with non-communicable disease risk in managing musculoskeletal health conditions with special reference to chronic pain?

Background

Other than activity and exercise, lifestyle practices such as not smoking and healthy nutrition, well established for preventing and managing lifestyle-related non-communicable diseases (i.e., heart disease, cancer, hypertension, stroke, obstructive lung disease, diabetes, and obesity), are less emphasized in the physical therapy guidelines for addressing chronic pain, e.g., back pain. This state-of-the-art review examines the relationships between lifestyle behaviours and musculoskeletal health, with special reference to chronic pain, and their clinical and research implications.

Discussion

A state-of-the-art review was conducted to synthesize evidence related to lifestyle factors (not smoking, healthy diet, healthy weight, optimal sleep and manageable stress, as well as physical activity) and musculoskeletal health, with special reference to chronic pain. The findings support that health behaviour change competencies (examination/assessment and intervention/treatment) may warrant being included in first-line management of chronic pain, either independently or in conjunction with conventional physical therapy interventions. To address knowledge gaps in the literature however three lines of clinical trial research are indicated: 1) to establish the degree to which traditional physical therapy interventions prescribed for chronic pain augment the benefits of lifestyle behaviour change; 2) to establish the degree to which adopting healthier lifestyle practices, avoids or reduces the need for conventional physical therapy; and 3) to establish whether patients/clients with healthier lifestyles and who have chronic pain, respond more favourably to conventional physical therapy interventions than those who have less healthy lifestyles.

Summary

Lifestyle behaviour change is well accepted in addressing lifestyle-related non-communicable diseases. Compelling evidence exists however supporting the need for elucidation of the role of negative lifestyle behaviours on the incidence of chronic pain, and the role of positive lifestyle behaviours on its incidence and effective management. Addressing lifestyle behaviour change in patients/clients with chronic pain, e.g., back pain, as a first-line intervention might not only constitute a novel approach, but also reduce the socioeconomic burden related to chronic pain as well as non-communicable diseases.