Objective Mechanical factors, in particular increased medial knee joint load, are believed to be important in the structural progression of knee osteoarthritis. This study evaluated the relationship of medial knee load during walking to indices of structural disease progression, measured on MRI, in people with medial knee osteoarthritis. Methods A longitudinal cohort design utilising a subset of participants (n=144, 72%) enrolled in a randomised controlled trial of lateral wedge insoles was employed. Medial knee load parameters including the peak knee adduction moment (KAM) and the KAM impulse were measured at baseline using three-dimensional gait analysis during walking. MRI at baseline and at 12 months was used to assess structural indices. Multiple regression with adjustment for covariates assessed the relationship between medial knee load parameters and the annual change in medial tibial cartilage volume. Binary logistic regression was used for the dichotomous variables of progression of medial tibiofemoral cartilage defects and bone marrow lesions (BML). Results A higher KAM impulse, but not peak KAM, at baseline was independently associated with greater loss of medial tibial cartilage volume over 12 months (β=29.9, 95% CI 6.3 to 53.5, p=0.01). No significant relationships were seen between medial knee load parameters and the progression of medial tibiofemoral cartilage defects or BML. Conclusion This study suggests knee loading, in particular the KAM impulse, may be a risk factor for loss of medial tibial cartilage volume. As knee load is modifiable, load-modifying treatments may potentially slow disease progression.

Objective To assess the effect of lateral wedge insoles compared with flat control insoles on improving symptoms and slowing structural disease progression in medial knee osteoarthritis. Design Randomised controlled trial. Setting Community in Melbourne, Australia. Participants 200 people aged 50 or more with clinical and radiographic diagnosis of mild to moderately severe medial knee osteoarthritis. Interventions Full length 5 degree lateral wedged insoles or flat control insoles worn inside the shoes daily for 12 months. Main outcome measures Primary symptomatic outcome was change in overall knee pain (past week) measured on an 11 point numerical rating scale. Primary structural outcome was change in volume of medial tibial cartilage from magnetic resonance imaging scans. Secondary clinical outcomes included changes in measures of pain, function, stiffness, and health related quality of life. Secondary structural outcomes included progression of medial cartilage defects and bone marrow lesions. Results Between group differences did not differ significantly for the primary outcomes of change in overall pain (−0.3 points, 95% confidence intervals −1.0 to 0.3) and change in medial tibial cartilage volume (−0.4 mm³, 95% confidence interval −15.4 to 14.6), and confidence intervals did not include minimal clinically important differences. None of the changes in secondary outcomes showed differences between groups. Conclusion Lateral wedge insoles worn for 12 months provided no symptomatic or structural benefits compared with flat control insoles. Trial registration Australian New Zealand Clinical Trials Registry ACTR12605000503628 and ClinicalTrials.gov NCT00415259.

Introduction: Given the emerging evidence that osteoarthritis (OA) may have a vascular basis, the aim of this study was to determine whether serum lipids were associated with change in knee cartilage, presence of bone marrow lesions (BMLs) at baseline and the development of new BMLs over a 2-year period in a population of pain-free women in mid-life. Methods: One hundred forty-eight women 40 to 67 years old underwent magnetic resonance imaging (MRI) of their dominant knee at baseline and 2.2 (standard deviation 0.12) years later. Cartilage volume and BMLs were determined for both time points. Serum lipids were measured from a single-morning fasting blood test approximately 1.5 years prior to the MRI. Results: The incidence of BML at follow-up was associated with higher levels of total cholesterol (odds ratio [OR] 1.84, 95% confidence interval [CI] 1.01, 3.36; P = 0.048) and triglycerides (OR 8.4, 95% CI 1.63, 43.43; P = 0.01), but not high-density lipoprotein (HDL) (P = 0.93), low-density lipoprotein (LDL) (P = 0.20) or total cholesterol/HDL ratio (P = 0.17). No association between total cholesterol, triglycerides, HDL, LDL or total cholesterol/HDL ratio and presence of BMLs at baseline or annual change in total tibial cartilage volume was observed. Conclusions: In this study of asymptomatic middle-aged women with no clinical knee OA, serum cholesterol and triglyceride levels were associated with the incidence of BMLs over 2 years. This provides support for the hypothesis that vascular pathology may have a role in the pathogenesis of knee OA. Further work is warranted to clarify this and whether treatments aimed at reducing serum lipids may have a role in reducing the burden of knee OA.

Objective: To examine the relationship between obesity, body composition, and foot pain as assessed by the Manchester Foot Pain and Disability Index (MFPDI).Methods: Subjects 25–62 years of age (n = 136) were recruited as part of a study examining the relationship between obesity and musculoskeletal health. Foot pain was defined as current foot pain and pain in the last month, and an MFPDI score of ≥1. Body composition (tissue mass and fat distribution) was measured using dual x‐ray absorptiometry.Results: The body mass index (BMI) in this population was normally distributed around a mean of 32.1 kg/m². The prevalence of foot pain was 55.1%. There was a positive association between BMI and foot pain (odds ratio [OR] 1.11, 95% confidence interval [95% CI] 1.06–1.17). Foot pain was also positively associated with fat mass (OR 1.05, 95% CI 1.02–1.09) and fat mass index (FMI; OR 1.16, 95% CI 1.06–1.28) when adjusted for age, sex, and skeletal muscle mass and age, sex, and fat‐free mass index (FFMI), respectively. When examining fat distribution, positive associations were observed for android/total body fat ratio (OR 1.42, 95% CI 1.11–1.83) and android/gynoid fat ratio (OR 35.15, 95% CI 2.60–475.47), although gynoid/total body fat ratio was inversely related to foot pain (OR 0.83, 95% CI 0.73–0.93). Skeletal muscle mass and FFMI were not associated with foot pain when adjusted for fat mass or FMI, respectively.Conclusion: Increasing BMI, specifically android fat mass, is strongly associated with foot pain and disability. This may imply both biomechanical and metabolic mechanisms.

Objective: Bone marrow lesions (BML) are important in established knee osteoarthritis, predicting pain and progression of disease. Whether BML are also associated with longitudinal changes in knee structure in an asymptomatic population is unknown. Methods: 148 healthy pain-free women in middle age with no history of knee injury or clinical knee osteoarthritis who had a magnetic resonance imaging (MRI) scan performed on their dominant knee at baseline, had another MRI 2 years later to assess whether having a BML present at baseline affected change in tibiofemoral cartilage defects and tibial cartilage volume. Results: BML were present in 14.9% of women at baseline. The risk of progression of total tibiofemoral cartilage defects was significantly higher when a very large BML was present (odds ratio 5.55, 95% CI 1.04 to 29.6) compared with when no BML was present, after adjusting for potential confounders. In the lateral compartment, the rate of cartilage volume loss was significantly greater when a BML was present after adjusting for confounders (regression coefficient 39.2 mm³, 95% CI 11.1 to 67.2, p = 0.007). Conclusions: In healthy women without pain at baseline, large BML were associated with both progression of cartilage defects in the whole tibiofemoral joint and more rapid lateral tibial cartilage loss. These data suggest that the relationship between BML and knee cartilage in healthy women is similar to that described in established osteoarthritis. It is possible that BML may predict an increased risk of knee osteoarthritis and facilitate the identification of novel interventions to prevent disease.