Longitudinal Changes in Adiposity After a Youth Sport-Related Knee Injury: Informing Posttraumatic Osteoarthritis...

Youth who experience a sport-related knee injury have elevated odds of becoming overweight or developing obesity in 3 to 10 years, compounding their risk for posttraumatic osteoarthritis (PTOA). To inform prevention strategies, this study compared patterns of adiposity change between youth with a sport-related knee injury and uninjured youth in the two-year period following injury.

This was a primary analysis of the Alberta Youth Prevention of Early Osteoarthritis Cohort prospective cohort study. Fat mass (bioelectrical impedance) of 186 youth (106 injured, 80 uninjured; 62% were female, mean age 16 ± 2 years) was assessed at baseline (≤ 4 months from injury) and follow-ups at 6, 12, 18, and 24 months. Linear mixed models examined the association between knee injury and fat mass change over time after adjusting for confounders. Missing data were addressed with multiple imputation.

The injured and uninjured groups did not experience differences in fat mass gain over the 24-month follow-up (0.1 kg; 95% confidence interval [CI] -0.6 to 0.9), and minimal to no differences in fat mass between groups were observed at any time point (6-month: 0.9; 95% CI -0.2 to 2.0; 12-month: 0.7; 95% CI -0.4 to 1.9; 18-month: -0.1; 95% CI -1.4 to 1.1; 24-month: -0.9; 95% CI -2.3 to 0.6), or between individuals with anterior cruciate ligament tear injuries versus other knee injuries, or female versus male sex.

Adiposity gains of youth with a sport-related knee injury over the initial two-year postinjury period may not differ from uninjured youth. Due to similar adiposity gains, the initial postinjury period is a potential window of opportunity to prevent becoming overweight or developing obesity in the future and knee PTOA.