Longitudinal effect of vigorous physical activity on patella cartilage morphology in people without clinical knee disease.

OBJECTIVE

There are few data concerning possible long-term effects of physical activity on cartilage change in the patellofemoral compartment. We examined the effect of participation in vigorous physical activity on changes to patella cartilage over 2 years.

METHODS

A total of 297 healthy adults ages 50-79 years with no history of knee injury or symptoms were recruited from an existing study. Physical activity data were obtained by questionnaire at baseline (2003-2004). Patella cartilage volume and defects were determined by magnetic resonance imaging at baseline (2003-2004) and followup (2006-2007).

RESULTS

Participation in vigorous physical activity at baseline was associated with a reduced rate of patella cartilage volume loss (-21.2 mm(3) per annum [95% confidence interval (95% CI) -41.5, -1.0; P = 0.04]) and a trend toward less risk of worsening patella cartilage defects (odds ratio 0.4; 95% CI 0.2, 1.1 [P = 0.07]) over the subsequent 2 years. In the subgroup with no significant patella cartilage defects at baseline (n = 192), participation in vigorous physical activity was associated with a reduced annual rate of patella cartilage volume loss (95% CI -53.8, -7.8; P = 0.03) and a trend for fewer new patella cartilage defects (95% CI 0.1, 1.1; P = 0.08). No significant relationships were found between vigorous physical activity and cartilage volume change or defect progression in the subgroup with prevalent patella cartilage defects at baseline.

CONCLUSION

These observations suggest that vigorous physical activity is beneficial to patellofemoral joints for people without preexisting cartilage damage. Weight-bearing vigorous physical activity might, therefore, be useful in the prevention of patellofemoral osteoarthritis.