Objective: To determine the relationship between different physical loading conditions and findings of knee osteoarthritis (OA).
Methods: We selected 117 male former top-level athletes (age range 45-68 years) who had participated in sports activities with distinctly different loading conditions: 28 had been long-distance runners, 31 soccer players, 29 weight lifters, and 29 shooters. Histories of lifetime occupational and athletic knee loading, knee injuries, and knee symptoms were obtained, and subjects were examined clinically and radiographically for knee findings of OA.
Results: The prevalence of tibiofemoral or patellofemoral OA based on radiographic examination was 3% in shooters, 29% in soccer players, 31% in weight lifters, and 14% in runners (P = 0.016 between groups). Soccer players had the highest prevalence of tibiofemoral OA (26%), and weight lifters had the highest prevalence of patellofemoral OA (28%). Subjects with radiographically documented knee OA had more symptoms, clinical findings, and functional limitations than did subjects without knee OA. By stepwise logistic regression analysis, the risk for having knee OA was increased in subjects with previous knee injuries (odds ratio [OR] 4.73), high body mass index at the age of 20 (OR 1.76/unit of increasing body mass index), previous participation in heavy work (OR 1.08/work-year), kneeling or squatting work (OR 1.10/work-year), and in subjects participating in soccer (OR 5.21).
Conclusion: Soccer players and weight lifters are at increased risk of developing premature knee OA. The increased risk is explained in part by knee injuries in soccer players and by high body mass in weight lifters.