Objective. To identify prospectively the possible risk factors for total hip replacement (THR) due to primary osteoarthritis in a large cohort.Methods. Data from a cardiovascular screening were matched with 9 years of national data on THR. Mean age at the start of followup was 54.9 years, and the 50,034 participants were followed up for an average of 9 years. During followup, 672 persons had a first THR due to primary osteoarthritis.Results. We found dose-response associations between body mass index (BMI), body weight, and the level of physical activity at work and THR for primary osteoarthritis. The highest versus the lowest quarter of BMI had a relative risk of 2.0 (95% confidence interval [95% CI] 1.4-2.9) among men and 3.0 (95% CI 2.1-4.1) among women. The highest versus the lowest quarter of body weight had a relative risk of 2.1 (95% CI 1.4-3.2) among men and 3.4 (95% CI 2.4-4.9) among women. Intensive versus sedentary physical activity at work had a relative risk of 2.1 (95% CI 1.5-3.0) among men and 2.1 (95% CI 1.3-3.3) among women. No association was found between physical activity in leisure and THR for primary osteoarthritis.Conclusion. Intensive physical activity at work and a high BMI each contribute significantly to the overall risk of undergoing THR due to primary osteoarthritis. Lowering the exposure to these risk factors may substantially reduce the need for hip replacement.

BackgroundOsteoarthritis (OA) of the knee is a common and disabling condition. We wanted to investigate the modifiable risk factors Body Mass Index (BMI) and physical activity, using knee replacement (KR) as a marker for severely symptomatic disease, focusing on the interaction between these risk factors.Methods315,495 participants (mean age 43.0 years) from national health screenings were followed prospectively with respect to KR identified by linkage to the Norwegian Arthroplasty Register. Data were analysed by Cox proportional hazard regression.ResultsDuring 12 years of follow up 1,323 individuals received KR for primary OA. There was a dose–response relationship between BMI and heavy labour, and later KR. Comparing the highest versus the lowest quarter of BMI, the relative risk was 6.2 (95% CI: 4.2-9.0) in men and 11.1 (95% CI: 7.8-15.6) in women. Men reporting intensive physical activity at work had a relative risk of 2.4 (95% CI: 1.8-3.2) versus men reporting sedentary activity at work, the corresponding figure in women being 2.3 (95% CI: 1.7-3.2). The effect of BMI and physical activity at work was additive. The heaviest men with the most strenuous work had a RR of 11.7 (95% CI: 5.9-23.1) compared to the ones with the lowest BMI and most sedentary work. For women the corresponding RR was 15.8 (95% CI: 8.2-30.3). There was no association between physical activity during leisure and KR.ConclusionWe found that a high BMI and intensive physical activity at work both contribute strongly to the risk of having a KR. As the two risk factors seem to act independently, people with strenuous physical work with a high BMI are at particularly high risk for severely disabling OA of the knee, and should be targeted with effective preventive measures.

Objective. To investigate the effects of body mass index (BMI), height, and age on the risk of later total hip arthroplasty for primary osteoarthritis (OA).Methods. We matched screening data on body height and weight from 1,152,006 persons ages 18-67 years who attended a compulsory screening for tuberculosis in 1963-1975 with data from the Norwegian Arthroplasty Register for the years 1987-2003. We identified 28,425 total hip replacements because of primary OA.Results. We found dose-response associations between both height and BMI and later hip arthroplasty. The relative risk (RR) among men with a BMI >32 kg/m 2 versus a BMI of 20.5-21.9 kg/m 2 was 3.4 (95% confidence interval [95% CI] 2.9-4.0). The corresponding RR in women was 2.3 (95% CI 2.1-2.4). There was a decreasing trend in the RR with an increasing age at screening. Among men, the RR for an increase of 5 kg/m 2 in the BMI was 2.1 (95% CI 1.7-2.5) when measured at age <25 years and 1.5 (95% CI 1.3-1.7) when measured at ages 55-59 years. Among women, the corresponding RR values were 1.7 (95% CI 1.5-1.9) and 1.1 (95% CI 1.1-1.2). Conclusion.There was a strong dose-response association between BMI and later total arthroplasty for OA of the hip. Being overweight entailed the highest RR among young participants, and the participants who were overweight at a young age maintained an excess RR for arthroplasty throughout the followup period.

IV.

Both methods return the patients to their pre-injury functional levels, but plate fixation has a faster recovery period in comminuted fractures than ESIN. ESIN has a shorter operative time and lower infection and implant rates of failure when using 2.5 mm nails or wider, suggesting that this is the preferred method in mid-shaft fractures with no comminution, whereas plate fixation is the superior method in comminuted fractures. Cite this article: 2017;99-B:1095-1101.