OrthopedicsToday
August 18, 2014
Patients with osteoarthritis who had high body mass index and performed intensive physical activity at work experienced a higher risk of having a knee replacement, according to study results.
Researchers prospectively followed 315,495 patients who underwent knee replacement and identified through the Norwegian Arthroplasty Register. Cox proportional hazard regression was used to analyze data.
Overall, 1,323 individuals underwent knee replacement for primary osteoarthritis (OA) during 12 years of follow-up. Study results showed a dose-response relationship between body mass index (BMI), heavy labor and eventual knee replacement.
When the researchers compared the highest and the lowest quarter of BMI, they found a relative risk (RR) of 6.2 in men and 11.1 in women. Compared with men and women who reported sedentary activity at work, men reporting intensive physical activity at work had a RR of 2.4, and women had a RR of 2.3.
The researchers also found a RR of 11.7 among the heaviest men who performed the most strenuous work and a RR of 15.8 among women compared with men and women with the lowest BMI and most sedentary work.
Although the effect of BMI and physical activity at work was additive, there was no association between physical activity during leisure and knee replacement, according to the researchers.
Disclosure: The authors have no relevant financial disclosures.