Background Osteoarthritis most commonly affects the patellofemoral compartment of the knee, being a major cause of pain and disability. The structural changes that evolve prior to the onset of symptoms can be visualised using magnetic resonance imaging (MRI). There is little known about the role of obesity on the early structural changes in the patella cartilage in younger, asymptomatic adult females.
Objectives The objective of this study was to examine the relationship between patella cartilage and obesity and change in obesity over the previous 10 years.
Methods 160 asymptomatic women (20-49years) participating in the Geelong Osteoporosis Study underwent knee MRI between 2006-8. Weight and body mass index (BMI) were measured 10 years prior (1994-7, baseline) and at the time of the MRI (current) with change over the period calculated (current-baseline). The relationships between the measures of obesity and patella cartilage volume and defects were examined.
Results After adjustment for age and patella bone volume, there was a reduction of 13 (95% CI -25.7, -0.55) microliters (mL) in patella cartilage volume for every 1 unit increase in current BMI and reduction of 27mL (95% CI -52.6, -1.5) per BMI unit increase over 10 years (p=0.04 for both). There was no significant association between baseline BMI and patella cartilage volume (p=0.16). Increased baseline and current weight and BMI were associated with increased prevalence of patella cartilage defects (all p<0.001).
Conclusions Obesity and weight gain over midlife are both associated with detrimental structural change at the patella in young to middle aged healthy women without clinical osteoarthritis. Maintaining a healthy weight, avoiding obesity and weight gain in younger asymptomatic women may be important in the prevention of patellofemoral osteoarthritis.
Disclosure of Interest None Declared