We examined the one-year risk of symptomatic venous thromboembolism (VTE) following primary total hip replacement (THR) among Danish patients and a comparison cohort from the general population. From the Danish Hip Arthroplasty Registry we identified all primary THRs performed in Denmark between 1995 and 2010 (n = 85 965). In all, 97% of patients undergoing THR received low-molecular-weight heparin products during hospitalisation. Through the Danish Civil Registration System we sampled a comparison cohort who had not undergone THR from the general population (n = 257 895). Among the patients undergoing THR, the risk of symptomatic VTE was 0.79% between 0 and 90 days after surgery and 0.29% between 91 and 365 days after surgery. In the comparison cohort the corresponding risks were 0.05% and 0.12%, respectively. The adjusted relative risks of symptomatic VTE among patients undergoing THR were 15.84 (95% confidence interval (CI) 13.12 to 19.12) during the first 90 days after surgery and 2.41 (95% CI 2.04 to 2.85) during 91 to 365 days after surgery, compared with the comparison cohort. The relative risk of VTE was elevated irrespective of the gender, age and level of comorbidity at the time of THR.

We concluded that THR was associated with an increased risk of symptomatic VTE up to one year after surgery compared with the general population, although the absolute risk is small.

We evaluated the short-term of 0 to 90 days and the longer term, up to 12.7 years, mortality for patients undergoing primary total hip replacement (THR) in Denmark in comparison to the general population. Through the Danish Hip Arthroplasty Registry we identified all primary THRs undertaken for osteoarthritis between 1 January 1995 and 31 December 2006. Each patient (n = 44 558) was matched at the time of surgery with three people from the general population (n = 133 674). We estimated mortality rates and mortality rate ratios with 95% confidence intervals for THR patients compared with the general population. There was a one-month period of increased mortality immediately after surgery among THR patients, but overall short-term mortality (0 to 90 days) was significantly lower (mortality rate ratio 0.8; 95% confidence interval 0.7 to 0.9). However, THR surgery was associated with increased short-term mortality in subjects under 60 years old, and among THR patients without comorbidity. Long-term mortality was lower among THR patients than in controls (mortality rate ratio 0.7; 95% confidence interval 0.7 to 0.7).

Overall, THR was associated with lower short- and long-term mortality among patients with osteoarthritis. Younger patients and patients without comorbidity before surgery may also experience increased mortality after THR surgery, although the absolute risk of death is small.