Two-year prospective longitudinal study exploring the factors associated with change in femoral cartilage volume in a cohort largely without knee radiographic osteoarthritis

Factors associated with trajectories of bone marrow lesions over 4 years: data from the Osteoarthritis Initiative

OBJECTIVE

To identify bone marrow lesion (BML) trajectories over 4 years and their demographic and structural predictors in middle-aged and older adults with or at increased risk of knee osteoarthritis (OA).

METHODS

A total of 614 participants (mean age 61 years, 62% female) from the Osteoarthritis Initiative cohort (OAI) were included. BMLs in 15 anatomical locations of the knee were measured annually from baseline to 4 years using the Magnetic Resonance Imaging Osteoarthritis Knee Score (MOAKS) method. BML trajectories were determined using latent class mixed models (LCMMs). Multinomial logistic regression was used to examine baseline characteristics that predicted BML trajectories.

RESULTS

Three distinct BML trajectories were identified: "Mild-stable BMLs" (25.9%), "Moderate-stable BMLs" (66.4%), and "Rapid-rise BMLs" (7.7%). Compared to the "Mild-stable BMLs" trajectory, current smokers were more likely to be in the "Moderate-stable BMLs" (odds ratio [OR] 2.089, P < 0.001) and "Rapid-rise" (OR 2.462, P < 0.001) trajectories. Moreover, female sex and meniscal tears were associated with an increased risk of being in the "Rapid-rise BMLs" trajectory (OR 2.023 to 2.504, P < 0.05). Participants who had higher education levels and drank more alcohol were more likely to be in the "Rapid-rise BMLs" trajectory (OR 1.624 to 3.178, P < 0.05) and less likely to be in the "Moderate-stable BMLs" trajectory (OR 0.668 to 0.674, P < 0.05).

CONCLUSIONS

During the 4-year follow-up, most participants had relatively stable BMLs, few had enlarged BMLs, and no trajectory of decreased BMLs was identified. Sociodemographic factors, lifestyle, and knee structural pathology play roles in predicting distinct BML trajectories.

Assessment of the relationship between smoking and meniscal injury

Objective

To determine whether being a smoker and the years of smoking correlate with the presence and degree of meniscal injury.

Materials and Methods

Individuals who underwent magnetic resonance imaging of the knee were divided into two groups: smokers and nonsmokers. For each smoker, the total smoking history was calculated by multiplying the daily consumption (packs/day) by the years of smoking, and the result is expressed as pack-years. In the evaluation of meniscal injury, the grade of injury was recorded. The thickness of the subcutaneous adipose tissue, as an indicator of obesity, was measured at the medial knee on axial plane images. The relationships that smoking and obesity had with meniscal injury were analyzed statistically.

Results

A total of 156 individuals were included in the study. The smoker group consisted of 48 individuals (30.8%), and the nonsmoker group consisted of 108 (69.2%). The meniscus was normal in one (2.1%) of the smokers and in 32 (29.6%) of the nonsmokers (p < 0.0001). The median subcutaneous adipose tissue thickness was 23 mm and 24 mm in the smokers and nonsmokers, respectively (p = 0.900). A moderate but statistically significant correlation was observed between packs/day and injury grade, as well as between pack-years and injury grade (r = 0.462, p = 0.001 and r = 0.523, p = 0.001, respectively). Smoking and age significantly increased the risk of meniscal injury, by 31.221 times (p = 0.001) and 1.076 times (p < 0.001), respectively.

Conclusion

Our findings indicate that current smoking and smoking history correlate significantly with meniscal injury grade.

Quantitative measurement of cartilage morphology in osteoarthritis: current knowledge and future directions

Quantitative measures of cartilage morphology ("cartilage morphometry") extracted from high resolution 3D magnetic resonance imaging (MRI) sequences have been shown to be sensitive to osteoarthritis (OA)-related change and also to treatment interventions. Cartilage morphometry is therefore nowadays widely used as outcome measure for observational studies and randomized interventional clinical trials. The objective of this narrative review is to summarize the current status of cartilage morphometry in OA research, to provide insights into aspects relevant for the design of future studies and clinical trials, and to give an outlook on future developments. It covers the aspects related to the acquisition of MRIs suitable for cartilage morphometry, the analysis techniques needed for deriving quantitative measures from the MRIs, the quality assurance required for providing reliable cartilage measures, and the appropriate participant recruitment criteria for the enrichment of study cohorts with knees likely to show structural progression. Finally, it provides an overview over recent clinical trials that relied on cartilage morphometry as a structural outcome measure for evaluating the efficacy of disease-modifying OA drugs (DMOAD).

The relationship between meniscal pathologies, cartilage loss, joint replacement and pain in knee osteoarthritis: a systematic review

OBJECTIVE

We conducted a systematic review in order to understand the relationship between imaging-visualised meniscus pathologies, hyaline cartilage, joint replacement and pain in knee osteoarthritis (OA).

DESIGN

A search of the Medline, Excerpta Medica database (EMBASE) and Cochrane library databases was performed for original publications reporting association between imaging-detected meniscal pathology (extrusion or tear/damage) and longitudinal and cross-sectional assessments of hyaline articular cartilage loss [assessed on magnetic resonance imaging (MRI)], incident joint replacement and pain (longitudinal and cross-sectional) in knee OA. Each association was qualitatively characterised by a synthesis of data from each analysis, based upon study design and quality scoring (including risk of bias assessment and adequacy of covariate adjustment using Cochrane recommended methodology).

RESULTS

In total 4,878 abstracts were screened and 82 publications were included (comprising 72 longitudinal analyses and 49 cross-sectional). Using high quality, well-adjusted data, meniscal extrusion and meniscal tear/damage were associated with longitudinal progression of cartilage loss, cross-sectional cartilage loss severity and joint replacement, independently of age, sex and body mass index (BMI). Medial and lateral meniscal tears were associated with cartilage loss when they occurred in the body and posterior horns, but not the anterior horns. There was a lack of high quality, well-adjusted meniscal pathology and pain publications and no clear independent association between meniscal extrusion or tear/damage with pain severity, progression in pain or incident frequent knee symptoms.

CONCLUSION

Meniscal features have strong associations with cartilage loss and joint replacement in knee OA, but weak associations with knee pain. Systematic review PROSPERO registration number: CRD 42020210910.

Elastic, Dynamic Viscoelastic and Model-Derived Fibril-Reinforced Poroelastic Mechanical Properties of Normal and Osteoarthritic Human Femoral Condyle Cartilage

Osteoarthritis (OA) degrades articular cartilage and weakens its function. Modern fibril-reinforced poroelastic (FRPE) computational models can distinguish the mechanical properties of main cartilage constituents, namely collagen, proteoglycans, and fluid, thus, they can precisely characterize the complex mechanical behavior of the tissue. However, these properties are not known for human femoral condyle cartilage. Therefore, we aimed to characterize them from human subjects undergoing knee replacement and from deceased donors without known OA. Multi-step stress-relaxation measurements coupled with sample-specific finite element analyses were conducted to obtain the FRPE material properties. Samples were graded using OARSI scoring to determine the severity of histopathological cartilage degradation. The results suggest that alterations in the FRPE properties are not evident in the moderate stages of cartilage degradation (OARSI 2-3) as compared with normal tissue (OARSI 0-1). Drastic deterioration of the FRPE properties was observed in severely degraded cartilage (OARSI 4). We also found that the FRPE properties of femoral condyle cartilage related to the collagen network (initial fibril-network modulus) and proteoglycan matrix (non-fibrillar matrix modulus) were greater compared to tibial and patellar cartilage in OA. These findings may inform cartilage tissue-engineering efforts and help to improve the accuracy of cartilage representations in computational knee joint models.

Association between meniscal volume and development of knee osteoarthritis

OBJECTIVE

To assess the association between meniscal volume, its change over time and the development of knee OA after 30 months in overweight/obese women.

METHODS

Data from the PRevention of knee Osteoarthritis in Overweight Females study were used. This cohort included 407 women with a BMI ≥ 27 kg/m2, free of OA-related symptoms. The primary outcome measure was incident OA after 30 months, defined by one out of the following criteria: medial or lateral joint space narrowing (JSN)  ≥ 1.0 mm, incident radiographic OA [Kellgren and Lawrence (K&L)  ≥ 2], or incident clinical OA. The secondary outcomes were either of these items separately. Menisci at both baseline and follow-up were automatically segmented to obtain meniscal volume and delta-volumes. Generalized estimating equations were used to evaluate associations between the volume measures and the outcomes.

RESULTS

Medial and lateral baseline and delta-volumes were not significantly associated to the primary outcome. Lateral meniscal baseline volume was significantly associated to lateral JSN [odds ratio (OR) = 0.87; 95% CI: 0.75, 0.99], while other measures were not. Medial and lateral baseline volume were positively associated to K&L incidence (OR = 1.32 and 1.22; 95% CI: 1.15, 1.50 and 1.03, 1.45, respectively), while medial and lateral delta-volume were negatively associated to K&L incidence (OR = 0.998 and 0.997; 95% CI: 0.997, 1.000 and 0.996, 0.999, respectively). None of the meniscal measures were significantly associated to incident clinical OA.

CONCLUSION

Larger baseline meniscal volume and the decrease of meniscal volume over time were associated to the development of structural OA after 30 months in overweight and obese women.

Knee effusion evaluated by ultrasonography warns knee osteoarthritis patients to develop their muscle atrophy: a three-year cohort study

This study aimed to elucidate the relationship between the quantitative value of suprapatellar effusion and the longitudinal changes in lower-extremity muscle mass (MM) in a cohort with knee osteoarthritis (KOA). Fifty-three subjects (106 legs) with bilateral radiographic KOA at baseline (BL) were enrolled. MM was calculated by bioimpedance analysis three times at BL, and at the one-year (1Y) and three-year (3Y) follow-ups. The longitudinal change in the lower-extremity MM was calculated by subtracting MM_BL from MM_1Y, and MM_1Y from MM_3Y. Subjects with ≥1.0 z-score loss were defined as having severe MM loss (SMML). Effusion was evaluated as the sagittal area of suprapatellar pouch (mm²) by ultrasonography. The ROC curve was drawn to determine the cut-off of effusion area. General estimating equations (GEEs) were conducted with the prevalence of SMML as the dependent variable and with the cut-off of effusion area as the independent variable. Sixteen legs (15.1%) demonstrated SMML_BL-1Y and another sixteen legs demonstrated SMML_1Y-3Y. GEEs revealed that individuals with ≥90 mm² effusion had significantly higher odds of SMML_BL-1Y prevalence (Odds ratio: 21.561; P-value: 0.003). Individuals with leachate knee effusion at BL had a significant risk of losing MM through the first year of the initial knee effusion assessment.

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.

Human adipose-derived mesenchymal stem cells for osteoarthritis: a pilot study with long-term follow-up and repeated injections

AIM

This study aimed to evaluate the safety and therapeutic potential of autologous human adipose-derived mesenchymal stem cells (haMSCs) in patients with osteoarthritis.

MATERIALS & METHODS

Safety and efficacy of haMSCs were preclinically assessed in vitro and in BALB/c-nu nude mice. 18 patients were enrolled and divided into three dose groups: the low-dose, mid-dose and high-dose group (1 × 10⁷, 2 × 10⁷ and 5 × 10⁷ cells, respectively), provided three injections and followed up for 96 weeks.

RESULTS & CONCLUSION

The preclinical study established the safety and efficacy of haMSCs. Intra-articular injections of haMSCs were safe and improved pain, function and cartilage volume of the knee joint, rendering them a promising novel treatment for knee osteoarthritis. The dosage of 5 × 10⁷ haMSCs exhibited the highest improvement (ClinicalTrials.gov Identifier: NCT01809769).

Expression of Genes and Their Polymorphism Influences the Risk of Knee Osteoarthritis

Introduction

Genetic factors including the level of expression of the fingerprint of genes involved in the development of bones and cartilage such as GDF-5 or ESR-α or CALM-1 are known to be strong determinants of the osteoarthritis (OA) in Caucasian and Oriental populations. Because of high prevalence of OA in Indian population and availability of limited genetic data, we determined whether similar genetic factors are involved in Indians as well.

Methods

A case control study was carried out involving 500 patients of knee OA and equal number of healthy controls. Genotyping analyses in whole blood, mRNA, and protein expressions in peripheral blood lymphocytes (PBLs) were performed using established protocols.

Results

Our results showed a significantly decreased level of mRNA and protein expressions for GDF-5, ESR-α, and CALM-1 genes in PBLs of OA cases when compared to healthy controls. The frequency of variant genotypes of these genes was also increased significantly in cases of OA compared to controls.

Conclusion

Our results demonstrated that the decrease in expression of GDF-5, ESR-α, and CALM-1 in PBLs and association of polymorphism in these genes may be important in predicting the severity and thereby the progression of OA in Indian population.

The relationship between three-dimensional knee MRI bone shape and total knee replacement-a case control study: data from the Osteoarthritis Initiative

Objective. There is growing understanding of the importance of bone in OA. Our aim was to determine the relationship between 3D MRI bone shape and total knee replacement (TKR).

Methods. A nested case-control study within the Osteoarthritis Initiative cohort identified case knees with confirmed TKR for OA and controls that were matched using propensity scores. Active appearance modelling quantification of the bone shape of all knee bones identified vectors between knees having or not having OA. Vectors were scaled such that −1 and +1 represented the mean non-OA and mean OA shapes.

Results. Compared to controls (n = 310), TKR cases (n = 310) had a more positive mean baseline 3D bone shape vector, indicating more advanced structural OA, for the femur [mean 0.98 vs −0.11; difference (95% CI) 1.10 (0.88, 1.31)], tibia [mean 0.86 vs −0.07; difference (95% CI) 0.94 (0.72, 1.16)] and patella [mean 0.95 vs 0.03; difference (95% CI) 0.92 (0.65, 1.20)]. Odds ratios (95% CI) for TKR per normalized unit of 3D bone shape vector for the femur, tibia and patella were: 1.85 (1.59, 2.16), 1.64 (1.42, 1.89) and 1.36 (1.22, 1.50), respectively, all P < 0.001. After including Kellgren–Lawrence grade in a multivariable analysis, only the femur 3D shape vector remained significantly associated with TKR [odds ratio 1.24 (1.02, 1.51)].

Conclusion. 3D bone shape was associated with the endpoint of this study, TKR, with femoral shape being most associated. This study contributes to the validation of quantitative MRI bone biomarkers for OA structure-modification trials.

Differences in subchondral bone size after one year in osteoarthritic and healthy knees

OBJECTIVE

Increase of subchondral bone area (tAB) in OA has been reported, but it remains unclear if this is specific to OA. We investigated differences in knee tAB after one year in healthy subjects and in those with radiographic OA (rOA).

METHOD

MR images of 899 right knees from the OA Initiative were acquired at baseline and one year follow-up (year-1). Medial and lateral tibial cartilage (MT and LT) and weight-bearing femoral cartilage (cMF and cLF) were segmented and tAB computed. Subjects were stratified into: healthy controls, pre-rOA (K&L grades 0 and 1, with OA risk factors), established rOA (K&L grades 2-4), and independently with regards to joint space narrowing (without, with medial, lateral and bilateral JSN). Primary analysis tested if tAB was different between baseline and year-1 in rOA. Exploratory analyses investigated whether: (1) tAB changes differed between healthy controls and those with rOA; (2) tAB differences were greater in higher K&L grades; and (3) tAB was different between baseline and year-1 in JSN. Significance was set at P < 0.0125.

RESULTS

Differences in tAB were found in rOA in MT, cMF and cLF (ranging from +0.2% to +0.4%; P < 0.001), but not in healthy controls or pre-rOA. Rates of change did not differ between groups. Within the JSN groups differences of 0.2-0.4% were found in the femur (P < 0.05).

CONCLUSION

We find that knee tABs differ in rOA between baseline and year-1, but the change was not greater than in healthy knees, and is restricted to the femur in JSN.

Does cartilage volume measurement or radiographic osteoarthritis at baseline independently predict ten-year cartilage volume loss?

Background

The aim of this study was to examine whether cartilage volume as measured by MRI and radiographic osteoarthritis (OA) at baseline predict cartilage volume loss over ten years independent of each other and other structural co-pathologies.

Methods

219 participants [mean-age 45(26–61); 57 % female] were studied at baseline and ten years. Approximately half were the adult offspring of subjects who underwent knee replacement for OA and the remainder were randomly selected controls. Joint space narrowing (JSN) and osteophytes were assessed on radiographs and cartilage volume (tibiofemoral), cartilage defects, bone marrow lesions and meniscal tears/extrusion were assessed on MRI.

Results

Mean absolute and percentage per annum cartilage volume loss was 1284 mm³ and 1.91 % respectively in the medial compartment and 1007 mm³ and 1.38 % respectively in the lateral compartment. Higher baseline tibiofemoral cartilage volume was independently associated with greater absolute cartilage volume loss in both medial (β(95 % CI) = −300 (−399,−200)) and lateral (β = −338 (−443,−233)) compartments and percentage per annum loss in the lateral compartment(β = −0.15 (−0.29, −0.01)). Baseline JSN and osteophytes were associated with cartilage volume loss in the univariable analysis, however these associations did not persist after adjustment for other structural co-pathologies.

Conclusion

Cross-sectional cartilage volume measurement independently predicts cartilage volume loss over 10 years and can be used to identify fast progressors in clinical trials. Radiographic JSN and osteophytes on the other hand are a reflection of other co-pathologies assessed on MRI and do not independently predict cartilage volume loss over 10 years.

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.

Baseline radiographic osteoarthritis and semi-quantitatively assessed meniscal damage and extrusion and cartilage damage on MRI is related to quantitatively defined cartilage thickness loss in knee osteoarthritis: the Multicenter Osteoarthritis Study

OBJECTIVES

To provide a comprehensive simultaneous relation of various semiquantitative knee OA MRI features as well as the presence of baseline radiographic osteoarthritis (OA) to quantitative longitudinal cartilage loss.

METHODS

We studied Multicenter OA Study (MOST) participants from a longitudinal observational study that included quantitative MRI measurement of cartilage thickness. These subjects also had Whole Organ MRI Score (WORMS) scoring of cartilage damage, bone marrow lesions (BMLs), meniscal pathology, and synovitis, as well as baseline radiographic evaluation for Kellgren and Lawrence (KL) grading. Knee compartments were classified as progressors when exceeding thresholds of measurement variability in normal knees. All potential risk factors of cartilage loss were dichotomized into "present" (score ≥2 for cartilage, ≥1 for others) or "absent". Differences in baseline scores of ipsi-compartmental risk factors were compared between progressor and non-progressor knees by multivariable logistic regression, adjusting for age, sex, body mass index, alignment axis (degrees) and baseline KL grade. Odds ratios (OR) and 95% CIs were calculated for medial femorotibial compartment (MFTC) and lateral femorotibial compartment (LFTC) cartilage loss. Cartilage loss across both compartments was studied using Generalized Estimating Equations.

RESULTS

196 knees of 196 participants were included (age 59.8 ± 6.3 years [mean ± SD], BMI 29.5 ± 4.6, 62% women). For combined analyses of MFTC and LFTC, baseline factors related to cartilage loss were radiographic OA (KL grade ≥2: aOR 4.8 [2.4-9.5], cartilage damage (aOR 2.3 [1.2-4.4])), meniscal damage (aOR 3.9 [2.1-7.4]) and extrusion (aOR 2.9 [1.6-5.3]), all in the ipsilateral compartment, but not BMLs or synovitis.

CONCLUSION

Baseline radiographic OA and semiquantitatively (SQ) assessed MRI-detected cartilage damage, meniscal damage and extrusion, but not BMLs or synovitis is related to quantitatively measured ipsi-compartmental cartilage thinning over 30 months.

Clinical significance of worsening versus stable preradiographic MRI lesions in a cohort study of persons at higher risk for knee osteoarthritis

BACKGROUND

Whether preradiographic lesions in knees at risk for osteoarthritis are incidental versus disease is unclear. We hypothesised, in persons without but at higher risk for knee osteoarthritis, that: 12-48 month MRI lesion status worsening is associated with 12-48 month incident radiographic osteoarthritis (objective component of clinical definition of knee osteoarthritis) and 48-84 month persistent symptoms.

METHODS

In 849 Osteoarthritis Initiative participants Kellgren/Lawrence (KL) 0 in both knees, we assessed cartilage damage, bone marrow lesions (BMLs), and menisci on 12 month (baseline) and 48 month MRIs. Multivariable logistic regression was used to evaluate associations between 12-48 month worsening versus stable status and outcome (12-48 month incident KL ≥1 and KL ≥2, and 48-84 month persistent symptoms defined as frequent symptoms or medication use most days of ≥1 month in past 12 month, at consecutive visits 48-84 months), adjusting for age, gender, body mass index (BMI), injury and surgery.

RESULTS

Mean age was 59.6 (8.8), BMI 26.7 (4.2) and 55.9% were women. 12-48 month status worsening of cartilage damage, meniscal tear, meniscal extrusion, and BMLs was associated with 12-48 month incident radiographic outcomes, and worsening of cartilage damage and BMLs with 48-84 month persistent symptoms. There was a dose-response association for magnitude of worsening of cartilage damage, meniscal tear, meniscal extrusion, and BMLs and radiographic outcomes, and cartilage damage and BMLs and persistent symptoms.

CONCLUSIONS

In persons at higher risk, worsening MRI lesion status was associated with concurrent incident radiographic osteoarthritis and subsequent persistent symptoms. These findings suggest that such lesions represent early osteoarthritis, and add support for a paradigm shift towards investigation of intervention effectiveness at this stage.

A systematic review of the relationship between subchondral bone features, pain and structural pathology in peripheral joint osteoarthritis

INTRODUCTION

Bone is an integral part of the osteoarthritis (OA) process. We conducted a systematic literature review in order to understand the relationship between non-conventional radiographic imaging of subchondral bone, pain, structural pathology and joint replacement in peripheral joint OA.

METHODS

A search of the Medline, EMBASE and Cochrane library databases was performed for original articles reporting association between non-conventional radiographic imaging-assessed subchondral bone pathologies and joint replacement, pain or structural progression in knee, hip, hand, ankle and foot OA. Each association was qualitatively characterised by a synthesis of the data from each analysis based upon study design, adequacy of covariate adjustment and quality scoring.

RESULTS

In total 2456 abstracts were screened and 139 papers were included (70 cross-sectional, 71 longitudinal analyses; 116 knee, 15 hip, six hand, two ankle and involved 113 MRI, eight DXA, four CT, eight scintigraphic and eight 2D shape analyses). BMLs, osteophytes and bone shape were independently associated with structural progression or joint replacement. BMLs and bone shape were independently associated with longitudinal change in pain and incident frequent knee pain respectively.

CONCLUSION

Subchondral bone features have independent associations with structural progression, pain and joint replacement in peripheral OA in the hip and hand but especially in the knee. For peripheral OA sites other than the knee, there are fewer associations and independent associations of bone pathologies with these important OA outcomes which may reflect fewer studies; for example the foot and ankle were poorly studied. Subchondral OA bone appears to be a relevant therapeutic target.

SYSTEMATIC REVIEW

PROSPERO registration number: CRD 42013005009.

Lifestyle modifications to improve musculoskeletal and bone health and reduce disability--a life-course approach

This review covers the evidence relating to lifestye modification in the big three musculoskeletal conditions: osteoarthritis, osteoporosis and rheumatoid arthritis. Lifestyle is of considerable importance in the first two and there is emerging evidence for rheumatoid arthritis despite it not traditionally being considered a lifestyle disease.

Relative distribution of quadriceps head anatomical cross-sectional areas and volumes--sensitivity to pain and to training intervention

INTRODUCTION

Quadriceps heads are important in biomechanical stabilization and in the pathogenesis osteoarthritis of the knee. This is the first study to explore the relative distribution of quadriceps head anatomical cross-sectional areas (ACSA) and volumes, and their response to pain and to training intervention.

METHODS

The relative proportions of quadriceps heads were determined in 48 Osteoarthritis Initiative participants with unilateral pain (65% women; age 45-78 years). Quadriceps head volumes were also measured in 35 untrained women (45-55 years) before and after 12-week training intervention. Cross-sectional areas of the vastus medialis (VM), inter-medius (VIM), and lateralis (VL), and of the rectus femoris (RF) were determined from axial T1-weighted MR images.

RESULTS

The proportion of the VM on the total quadriceps ACSA increased from proximal to distal. The difference in quadriceps ACSA of painful (vs. pain-free) limbs was -5.4% for the VM (p<0.001), -6.8% for the VL (p<0.01), -2.8% for the VIM (p=0.06), and +3.4% for the RF (p=0.67) but the VM/VL ratio was not significantly altered. The muscle volume increase during training intervention was +4.2% (p<0.05) for VM, +1.3% for VL, +2.0% for VIM (p<0.05) and +1.6% for RF.

CONCLUSION

The proportion of quadriceps head relative to total muscle ACSA and volume depends on the anatomical level studied. The results suggest that there may be a differential response of the quadriceps heads to pain-induced atrophy and to training-related hypertrophy. Studies in larger samples are needed to ascertain whether the observed differences in response to pain and training are statistically and clinically significant.

Increasing lateral tibial slope: is there an association with articular cartilage changes in the knee?

PURPOSE

The geometry of the lateral tibial slope (LTS) plays an important role in the overall biomechanics of the knee. Through this study, we aim to assess the impact of LTS on cartilage degeneration in the knee.

MATERIALS AND METHODS

A retrospective analysis of 93 knee MRI scans (1.5 T or 3 T) for patients aged 20-45 years with no history of trauma or knee surgery, and absence of internal derangement. The LTS was calculated using the circle method. Chondropathy was graded from 0 (normal) to 3 (severe). Linear regression analysis was used for statistical analysis (p < 0.05).

RESULTS

In our cohort of patients, a statistically significant association was seen between increasing LTS and worsening cartilage degenerative changes in the medial patellar articular surface and the lateral tibial articular surface (p < 0.05). There was no statistically significant association between increasing LTS and worsening chondropathy of the lateral patellar, medial trochlea, lateral trochlea, medial femoral, lateral femoral, and medial tibial articular surfaces.

CONCLUSIONS

Our results show a statistically significant association between increasing LTS and worsening cartilage degenerative changes in the medial patella and the lateral tibial plateau. We speculate that increased LTS may result in increased femoral glide over the lateral tibial plateau with subsequent increased external rotation of the femur predisposing to patellofemoral articular changes. Future arthroscopic studies are needed to further confirm our findings.

Age and obesity alter the relationship between femoral articular cartilage thickness and ambulatory loads in individuals without osteoarthritis

Articular cartilage is sensitive to mechanical loading, so increased risk of osteoarthritis in older or obese individuals may be linked to changes in the relationship between cartilage properties and extrinsic joint loads. A positive relationship has been reported between ambulatory loads and cartilage thickness in young individuals, but whether this relationship exists in individuals who are older or obese is unknown. This study examined the relationship between femoral cartilage thickness and load, measured by weight × height and the peak adduction moment, in young normal-weight (28 subjects, age: 28.0 ± 3.8 years, BMI: 21.9 ± 1.9 kg/m(2)), middle-aged normal-weight (27 subjects, 47.0 ± 6.5 years, 22.7 ± 1.7 kg/m(2)), young overweight/obese (27 subjects, 28.4 ± 3.6 years, 33.3 ± 4.6 kg/m(2)), and middle-aged overweight/obese (27 subjects, 45.8 ± 7.2 years, 31.9 ± 4.4 kg/m(2)) individuals. On the lateral condyle, cartilage thickness was positively correlated with weight × height for all groups (R(2)  = 0.26-0.20) except the middle-aged overweight/obese. On the medial condyle, weight × height was significantly correlated only in young normal-weight subjects (R(2)  = 0.19), as was the case for the correlation between adduction moment and medial-lateral thickness ratio (R(2)  = 0.20). These results suggest that aging and obesity are both associated with a loss of the positive relationship between cartilage thickness and ambulatory loads, and that the relationship is dependent on the compartment and whether the load is generated by body size or subject-specific gait mechanics.

Exercise and osteoarthritis: cause and effects

Osteoarthritis (OA) is a common chronic joint condition predominantly affecting the knee, hip, and hand joints. Exercise plays a role in the development and treatment of OA but most of the literature in this area relates to knee OA. While studies indicate that exercise and physical activity have a generally positive effect on healthy cartilage metrics, depending upon the type of the activity and its intensity, the risk of OA development does appear to be moderately increased with sporting participation. In particular, joint injury associated with sports participation may be largely responsible for this increased risk of OA with sport. Various repetitive occupational tasks are also linked to greater likelihood of OA development. There are a number of physical impairments associated with OA including pain, muscle weakness and altered muscle function, reduced proprioception and postural control, joint instability, restricted range of motion, and lower aerobic fitness. These can result directly from the OA pathological process and/or indirectly as a result of factors such as pain, effusion, and reduced activity levels. These impairments and their underlying physiology are often targeted by exercise interventions and evidence generally shows that many of these can be modified by specific exercise. There is currently little clinical trial evidence to show that exercise can alter mechanical load and structural disease progression in those with established OA, although a number of impairments, that are amenable to change with exercise, appears to be associated with increased mechanical load and/or disease progression in longitudinal studies.

Baseline and longitudinal change in isometric muscle strength prior to radiographic progression in osteoarthritic and pre-osteoarthritic knees--data from the Osteoarthritis Initiative

OBJECTIVE

To test whether cross-sectional or longitudinal measures of thigh muscle isometric strength differ between knees with and without subsequent radiographic progression of knee osteoarthritis (KOA), with particular focus on pre-osteoarthritic female knees (knees with risk factors but without definite radiographic KOA).

METHODS

Of 4,796 Osteoarthritis Initiative participants, 2,835 knees with Kellgren Lawrence grade (KLG) 0-3 had central X-ray readings, annual quantitative joint space width (JSW) and isometric muscle strength measurements (Good strength chair). Separate slope analysis of covariance (ANCOVA) models were used to determine differences in strength between "progressor" and "non-progressor" knees, after adjusting for age, body mass index, and pain.

RESULTS

466 participant knees exceeded the smallest detectable JSW change during each of two observation intervals (year 2→4 and year 1→3) and were classified as progressors (213 women, 253 men; 128 KLG0/1, 330 KLG2/3); 946 participant knees did not exceed this threshold in either interval and were classified as non-progressors (588 women, 358 from men; 288KLG0/1, 658KLG2/3). Female progressor knees, including those with KLG0/1, tended to have lower extensor and flexor strength at year 2 and at baseline than those without progression, but the difference was not significant after adjusting for confounders. No significant difference was observed in longitudinal change of muscle strength (baseline→year 2) prior to radiographic progression. No significant differences were found for muscle strength in men, and none for change in strength concomitant with progression.

CONCLUSION

This study provides no strong evidence that (changes in) isometric muscle strength precedes or is associated with structural (radiographic) progression of KOA.

The musculoskeletal effects of cigarette smoking

➤ Cigarette smoking decreases bone mineral density and increases the risk of sustaining a fracture or tendon injury, with partial reversibility of these risks with long-term cessation of smoking. ➤ Cigarette smoking increases the risk for perioperative complications, nonunion and delayed union of fractures, infection, and soft-tissue and wound-healing complications. ➤ Brief preoperative cessation of smoking may mitigate these perioperative risks. ➤ Informed-consent discussions should include notification of the higher risk of perioperative complications with cigarette smoking and the benefits of temporary cessation of smoking.

Is quadriceps muscle weakness a risk factor for incident or progressive knee osteoarthritis?

The role of the quadriceps muscle in mediating risk for knee osteoarthritis (OA) is a common subject of investigation. The quadriceps muscle is a principal contributor to knee joint stability and provides shock absorption for the knee during ambulation. Clinically, weakness of the quadriceps muscle is consistently found in patients with knee OA. Research has shown that higher quadriceps muscle strength is associated with a reduced risk for incident symptomatic knee OA. However, there is limited evidence to suggest that quadriceps muscle plays a significant role in the incidence of radiographic knee OA. In addition, greater quadriceps muscle strength is associated with a lower risk for progression of tibiofemoral joint space narrowing and cartilage loss in women. This article summarizes knowledge of the relationship between quadriceps muscle strength and risk for knee OA.

Advances in imaging of osteoarthritis and cartilage

Osteoarthritis (OA) is the most frequent form of arthritis, with major implications for individual and public health care without effective treatment available. The field of joint imaging, and particularly magnetic resonance (MR) imaging, has evolved rapidly owing to technical advances and the application of these to the field of clinical research. Cartilage imaging certainly is at the forefront of these developments. In this review, the different aspects of OA imaging and cartilage assessment, with an emphasis on recent advances, will be presented. The current role of radiography, including advances in the technology for joint space width assessment, will be discussed. The development of various MR imaging techniques capable of facilitating assessment of cartilage morphology and the methods for evaluating the biochemical composition of cartilage will be presented. Advances in quantitative morphologic cartilage assessment and semiquantitative whole-organ assessment will be reviewed. Although MR imaging is the most important modality in imaging of OA and cartilage, others such as ultrasonography play a complementary role that will be discussed briefly.

Quantitative cartilage imaging in knee osteoarthritis

Quantitative measures of cartilage morphology (i.e., thickness) represent potentially powerful surrogate endpoints in osteoarthritis (OA). These can be used to identify risk factors of structural disease progression and can facilitate the clinical efficacy testing of structure modifying drugs in OA. This paper focuses on quantitative imaging of articular cartilage morphology in the knee, and will specifically deal with different cartilage morphology outcome variables and regions of interest, the relative performance and relationship between cartilage morphology measures, reference values for MRI-based knee cartilage morphometry, imaging protocols for measurement of cartilage morphology (including those used in the Osteoarthritis Initiative), sensitivity to change observed in knee OA, spatial patterns of cartilage loss as derived by subregional analysis, comparison of MRI changes with radiographic changes, risk factors of MRI-based cartilage loss in knee OA, the correlation of MRI-based cartilage loss with clinical outcomes, treatment response in knee OA, and future directions of the field.

Circulating levels of IL-6 and TNF-α are associated with knee radiographic osteoarthritis and knee cartilage loss in older adults

OBJECTIVE

The role of inflammation in osteoarthritis (OA) pathogenesis is unclear, and the associations between inflammatory cytokines and cartilage loss have not been reported. We determined the associations between serum levels of interleukin (IL)-6 and tumor necrosis factor-α (TNF-α), knee radiographic OA (ROA) and cartilage loss over 2.9 years in older adults.

METHODS

A total of 172 randomly selected subjects (mean 63 years, range 52-78, 47% female) were studied at baseline and approximately 3 (range 2.6-3.3) years later. IL-6 and TNF-α were assessed by radioimmunoassay. T1-weighted fat-suppressed magnetic resonance imaging of the right knee was performed at baseline and follow-up to determine knee cartilage volume. Knee ROA of both knees was assessed at baseline.

RESULTS

At baseline, quartiles of IL-6 and TNF-α were associated with increased prevalence of medial tibiofemoral joint space narrowing (OARSI grade ≥ 1) in multivariate analyses [odds ratio (OR): 1.42 and 1.47 per quartile, respectively, both P<0.05]. Longitudinally, baseline IL-6 predicted loss of both medial and lateral tibial cartilage volume (β: -1.19% and -1.35% per annum per quartile, P<0.05 and P<0.01, respectively), independently of TNF-α. Change in IL-6 was associated with increased loss of medial and lateral tibial cartilage volume (β: -1.18% and -1.06% per annum per quartile, both P<0.05) and change in TNF-α was also negatively associated with change in medial cartilage volume (β: -1.27% per annum per quartile, P<0.05).

CONCLUSIONS

Serum levels of IL-6 and TNF-α are associated with knee cartilage loss in older people suggesting low level inflammation plays a role in the pathogenesis of knee OA.

Anatomically corresponded regional analysis of cartilage in asymptomatic and osteoarthritic knees by statistical shape modelling of the bone

Magnetic resonance imaging (MRI) is emerging as the method of choice for measuring cartilage loss in osteoarthritis (OA), but current methods of analysis are imperfect for therapeutic clinical trials. In this paper, we present and evaluate, in two multicenter multivendor studies, a new method for anatomically corresponded regional analysis of cartilage (ACRAC) that allows analysis of knee cartilage morphology in anatomically corresponding focal regions defined on the bone surface. In our first study, 3-D knee MR Images were obtained from 19 asymptomatic female volunteers, followed by segmentations of the bone and cartilage. Minimum description length (MDL) statistical shape models (SSMs) were constructed from the segmented bone surfaces, providing mean bone shapes and a dense set of anatomically corresponding positions on each individual bone, the accuracy of which were measured using repeat images from a subset of the volunteers. Cartilage thicknesses were measured at these locations along 3-D normals to the bone surfaces, yielding corresponded cartilage thickness maps. Functional subregions of the joint were defined on the mean bone shapes, and propagated, using the correspondences, to each individual. ACRAC improved reproducibility, particularly in the central, load bearing subregions of the joint, compared with measures of volume obtained directly from the segmented cartilage surfaces. In our second study, MR Images were obtained from 31 female patient-volunteers with knee OA at baseline and six months. We obtained manual segmentations of the cartilage, and automatic segmentations of the bone using active appearance models (AAMs) built from the bone SSMs of the first study. ACRAC enabled the detection of significant thickness loss in the central, load-bearing regions of the whole femur (-5.57% p = 0.01, annualized) and the medial condyle (-13.08% , p = 0.024 Bonferroni corrected, annualized). We conclude that statistical shape modelling of bone surfaces defines correspondences invariant to individual joint size or shape, providing focal measures of cartilage with improved reproducibility compared to whole compartment measures. It permits the identification of anatomically equivalent regions, and provides the ability to identify the main load-bearing regions of the joint, based on the imputed premorbid state. The method permitted detection of tiny morphological change in cartilage thickness over six months in a small study, and may be useful for OA disease analysis and treatment monitoring.

Validation of cartilage thickness calculations using indentation analysis

Different methods have been used to cross-validate cartilage thickness measurements from magnetic resonance images (MRIs); however, a majority of these methods rely on interpolated data points, regional mean and/or maximal thickness, or surface mean thickness for data analysis. Furthermore, the accuracy of MRI cartilage thickness measurements from commercially available software packages has not necessarily been validated and may lead to an under- or overestimation of cartilage thickness. The goal of this study was to perform a matching point-to-point validation of indirect cartilage thickness calculations using a magnetic resonance (MR) image data set with direct cartilage thickness measurements using biomechanical indentation testing at the same anatomical locations. Seven bovine distal femoral condyles were prepared and a novel phantom filled with dilute gadolinium solution was rigidly attached to each specimen. High resolution MR images were acquired, and thickness indentation analysis of the cartilage was performed immediately after scanning. Segmentation of the MR data and cartilage thickness calculation was performed using semi-automated software. Registration of MR and indentation data was performed using the fluid filled phantom. The inter- and intra-examiner differences of the measurements were also determined. A total of 105 paired MRI-indentation thickness data points were analyzed, and a significant correlation between them was found (r=0.88, p<0.0001). The mean difference (+/-std. dev.) between measurement techniques was 0.00+/-0.23 mm, with Bland-Altman limits of agreement of 0.45 mm and -0.46 mm. The intra- and inter-examiner measurement differences were 0.03+/-0.22 mm and 0.05+/-0.24 mm, respectively. This study validated cartilage thickness measurements from MR images with thickness measurements from indentation by using a novel phantom to register the image-based and laboratory-based data sets. The accuracy of the measurements was comparable to previous cartilage thickness validation studies in literature. The results of this study will aid in validating a tool for clinical evaluation of in-vivo cartilage thickness.

Isometric quadriceps strength in women with mild, moderate, and severe knee osteoarthritis

OBJECTIVE

Quadriceps weakness is a common clinical sign in persons with moderate-to-severe osteoarthritis and results in physical disability; however, minimal data exist to establish whether quadriceps weakness is present in early stages of the disease. Therefore, our purpose was to determine whether quadriceps weakness was present in persons with early radiographic and cartilaginous evidence of osteoarthritis. Further, we sought to determine whether quadriceps strength decreases as osteoarthritis severity increases.

DESIGN

Three hundred forty-eight women completed radiologic and magnetic resonance imaging evaluation, in addition to strength testing. Anterior-posterior radiographs were graded for tibiofemoral osteoarthritis severity using the Kellgren-Lawrence scale. Scans from magnetic resonance imaging were used to assess medial tibiofemoral and patellar cartilage based on a modification of the Noyes scale. The peak knee extension torque recorded was used to represent strength.

RESULTS

Quadriceps strength (Nm/kg) was 22% greater in women without radiographic osteoarthritis than in women with osteoarthritis (P < 0.05). Quadriceps strength was also greater in women with Noyes' medial tibial and femoral cartilage scores of 0 when compared in women with Noyes' grades 2 and 3-5 (P < or = 0.05).

CONCLUSIONS

Women with early evidence of osteoarthritis had less quadriceps strength than women without osteoarthritis as defined by imaging.

Sensitivity to change of cartilage morphometry using coronal FLASH, sagittal DESS, and coronal MPR DESS protocols--comparative data from the Osteoarthritis Initiative (OAI)

OBJECTIVE

The Osteoarthritis Initiative (OAI) is targeted at identifying sensitive biomarkers and risk factors of symptomatic knee osteoarthritis (OA) onset and progression. Quantitative cartilage imaging in the OAI relies on validated fast low angle shot (FLASH) sequences that suffer from relatively long acquisition times, and on a near-isotropic double echo steady-state (DESS) sequence. We therefore directly compared the sensitivity to cartilage thickness changes and the correlation of these protocols longitudinally.

METHODS

Baseline (BL) and 12 month follow-up data of 80 knees were acquired using 1.5 mm coronal FLASH and 0.7 mm sagittal DESS (sagDESS) sequences. In these and in 1.5 mm coronal multi-planar reconstructions (MPR) of the DESS the medial femorotibial cartilage was segmented with blinding to acquisition order. In the weight-bearing femoral condyle, a 60% (distance between the trochlear notch and the posterior femur) and a 75% region of interest (ROI) were studied.

RESULTS

The standardized response mean (SRM = mean change/standard deviation of change) in central medial femorotibial (cMFTC) cartilage thickness was -0.34 for coronal FLASH, -0.37 for coronal MPR DESS, -0.36 for sagDESS with the 60% ROI, and -0.38 for the 75% ROI. Using every second 0.7 mm sagittal slice (DESS) yielded similar SRMs in cMFTC for the 60% and 75% ROI from odd (-0.35/-0.36) and even slice numbers (-0.36/-0.39), respectively. BL cartilage thickness displayed high correlations (r > or = 0.94) between the three protocols; the correlations of longitudinal changes were > or = 0.79 (Pearson) and > or = 0.45 (Spearman).

CONCLUSIONS

Cartilage morphometry with FLASH and DESS displays similar longitudinal sensitivity to change. Analysis of every second slice of the 0.7 mm DESS provides adequate sensitivity to change.

Measurement and visualisation of focal cartilage thickness change by MRI in a study of knee osteoarthritis using a novel image analysis tool

We describe the application of a novel analysis method that provides detailed maps of changes in cartilage thickness measured from MRI scans for individuals and cohorts of patients together with regional measures. A cohort of osteoarthritis patients was imaged using a 1.0 T MR scanner over a 36-month period. Hyaline cartilage was manually segmented from a three-dimensional (3D) spoiled gradient-echo sequence with fat suppression. Representative outlines of the bone surfaces of the distal femur and proximal tibia were automatically generated from T₂ weighted images using statistical models of the shape and appearance of the bones. Cartilage thickness was measured from a dense set of points representing the bony surface. The models of the bones provided a common frame of reference, relative to which change maps were generated and aggregated across the cohort and anatomically corresponding subregions of the joint to be identified. In the reproducibility arm involving six patients, the thickness of cartilage had coefficients of variation of 2.66% within the tibiofemoral joint and 2.94% within the medial femoral condyle region. In the 9 patients (6 female, 3 male) who completed the 36-month study, the most striking observation was that lack of change in global measures of cartilage thickness concealed substantial focal changes. Specifically, the cartilage thickness within the tibiofemoral joint decreased by 0.85% per annum (95% CI -2.13% to 0.45%) with the medial femoral condyle as the region with the most significant change, decreasing by 2.43% per annum (uncorrected 95% CI -4.31% to 0.51%).

Magnetic resonance imaging-based semiquantitative and quantitative assessment in osteoarthritis

Whole organ magnetic resonance imaging (MRI)-based semiquantitative (SQ) assessment of knee osteoarthritis (OA), based on reliable scoring methods and expert reading, has become a powerful research tool in OA. SQ morphologic scoring has been applied to large observational cross-sectional and longitudinal epidemiologic studies as well as interventional clinical trials. SQ whole organ scoring analyzes all joint structures that are potentially relevant as surrogate outcome measures of OA and potential disease modification, including cartilage, subchondral bone, osteophytes, intra- and periarticular ligaments, menisci, synovial lining, cysts, and bursae. Resources needed for SQ scoring rely on the MRI protocol, image quality, experience of the expert readers, method of documentation, and the individual scoring system that will be applied. The first part of this article discusses the different available OA whole organ scoring systems, focusing on MRI of the knee, and also reviews alternative approaches. Rheumatologists are made aware of artifacts and differential diagnoses when applying any of the SQ scoring systems. The second part focuses on quantitative approaches in OA, particularly measurement of (subregional) cartilage loss. This approach allows one to determine minute changes that occur relatively homogeneously across cartilage structures and that are not apparent to the naked eye. To this end, the cartilage surfaces need to be segmented by trained users using specialized software. Measurements of knee cartilage loss based on water-excitation spoiled gradient recalled echo acquisition in the steady state, fast low-angle shot, or double-echo steady-state imaging sequences reported a 1% to 2% decrease in cartilage thickness annually, and a high degree of spatial heterogeneity of cartilage thickness changes in femorotibial subregions between subjects. Risk factors identified by quantitative measurement technology included a high body mass index, meniscal extrusion and meniscal tears, knee malalignment, advanced radiographic OA grade, bone marrow alterations, and focal cartilage lesions.

The robust association between childhood physical abuse and osteoarthritis in adulthood: findings from a representative community sample

OBJECTIVE

Research suggests a role of early-life trauma in the development of arthritis. This study investigated the relationship between childhood physical abuse and osteoarthritis (OA) while controlling for age, sex, race, and socioeconomic status (SES), in addition to the following types of risk factors for OA: 1) concurrent childhood stressors, 2) adult health behaviors, and 3) depression.

METHODS

Data from the provinces of Manitoba and Saskatchewan were selected from the 2005 Canadian Community Health Survey (n = 13,093). Respondents with missing arthritis data or with arthritis types other than OA were excluded (n = 1,985). Of the 11,108 remaining respondents, 6.9% (n = 854) reported childhood physical abuse by someone close to them, and 10.1% (n = 1,452) reported that they had been diagnosed with OA by a health professional. The regional-level response rate was 84%.

RESULTS

When adjusting for all 3 types of risk factors, a significant association between childhood physical abuse and OA was found (odds ratio [OR] 1.56, 95% confidence interval [95% CI] 1.21-2.00). In contrast, when adjusting for age, sex, race, and SES only, the OR was 1.99 (95% CI 1.57-2.52).

CONCLUSION

The association between childhood physical abuse and OA remained significant, even after controlling for many risk factors that may mediate the relationship. Further research is needed to investigate potential pathways through which arthritis develops as a consequence of childhood physical abuse.

Serum levels of vitamin D, sunlight exposure, and knee cartilage loss in older adults: the Tasmanian older adult cohort study

OBJECTIVE

To determine the associations between serum levels of vitamin D, sunlight exposure, and knee cartilage loss cross-sectionally and longitudinally in older adults.

METHODS

A total of 880 randomly selected subjects (mean age 61 years [range 51-79 years], 50% women) were studied at baseline, and 353 of these subjects were studied 2.9 years later. Serum levels of 25-hydroxyvitamin D (25[OH]D) were assessed by radioimmunoassay, and sunlight exposure was assessed by questionnaire. T1-weighted fat-suppressed magnetic resonance imaging (MRI) of the right knee was performed to determine knee cartilage volume and defects. Knee radiographic osteoarthritis (OA) and knee pain were also assessed.

RESULTS

The mean 25(OH)D serum level was 52.8 nmoles/liter at baseline (range 13-119 nmoles/liter). Winter sunlight exposure and serum 25(OH)D level were both positively associated with medial and lateral tibial cartilage volume, and a serum 25(OH)D level<50 nmoles/liter was associated with increased medial tibiofemoral joint space narrowing (all P<0.05). Longitudinally, baseline serum 25(OH)D level predicted change in both medial and lateral tibial cartilage volume (beta=+0.04% per annum per nmole/liter for both; P<0.05), and change in serum 25(OH)D level was positively associated with change in medial tibial cartilage volume. These associations were consistent in subjects with radiographic OA and knee pain and/or in women, but not in men or in subjects without radiographic OA or knee pain.

CONCLUSION

Sunlight exposure and serum 25(OH)D levels are both associated with decreased knee cartilage loss (assessed by radiograph or MRI). This is best observed using the whole range of 25(OH)D levels rather than predefined cut points and implies that achieving vitamin D sufficiency may prevent and/or retard cartilage loss in knee OA.

Resistive Exercise for Arthritic Cartilage Health (REACH): a randomized double-blind, sham-exercise controlled trial

Background

This article provides the rationale and methodology, of the first randomised controlled trial to our knowledge designed to assess the efficacy of progressive resistance training on cartilage morphology in women with knee osteoarthritis.

Development and progression of osteoarthritis is multifactorial, with obesity, quadriceps weakness, joint malalignment, and abnormal mechanical joint forces particularly relevant to this study. Progressive resistance training has been reported to improve pain and disability in osteoarthritic cohorts. However, the disease-modifying potential of progressive resistance training for the articular cartilage degeneration characteristic of osteoarthritis is unknown. Our aim was to investigate the effect of high intensity progressive resistance training on articular cartilage degeneration in women with knee osteoarthritis.

Methods

Our cohort consisted of women over 40 years of age with primary knee osteoarthritis, according to the American College of Rheumatology clinical criteria. Primary outcome was blinded measurement of cartilage morphology via magnetic resonance imaging scan of the tibiofemoral joint. Secondary outcomes included walking endurance, balance, muscle strength, endurance, power, and velocity, body composition, pain, disability, depressive symptoms, and quality of life.

Participants were randomized into a supervised progressive resistance training or sham-exercise group. The progressive resistance training group trained muscles around the hip and knee at 80% of their peak strength and progressed 3% per session, 3 days per week for 6 months. The sham-exercise group completed all exercises except hip adduction, but without added resistance or progression. Outcomes were repeated at 3 and 6 months, except for the magnetic resonance imaging scan, which was only repeated at 6 months.

Discussion

Our results will provide an evaluation of the disease-modifying potential of progressive resistance training for osteoarthritis.

Trial Registration

ANZCTR Reference No. 12605000116628