Changes in mortality patterns following total hip or knee arthroplasty over the past two decades: A nationwide cohort study

Introduction: THR / TKR surgery are effective procedures for patients with moderate-to-severe osteoarthritis. Mortality rates after THR and TKR may have changed because of new surgical techniques, improvement of peri- and postoperative care, and patients having more comorbidity. Data on secular mortality trends are however scarce. The objective was to evaluate mortality patterns between 1989 and 2007 in patients undergoing elective total hip (THR) and knee (TKR) surgery. Methods: In a Danish retrospective nationwide cohort study, 71,812 THR and 40,642 TKR patients were identified between January 1989 and December 2007. Mortality (all-cause and disease-specific) was assessed, stratified by calendar time. Using Cox proportional hazards models, relative rates (RRs) for mortality were calculated between different calendar time periods, adjusted for age, sex, and comorbid diseases. Results: Since the early 90s, short-term survival following elective THR and TKR surgery has greatly improved. As compared to 1989-1991, 60-day mortality rates were substantially lower between 2004 and 2007 for THR (RR 0.40, 95% CI 0.28-0.58) and TKR patients (RR 0.37, 95% CI 0.21-0.67). This trend was far more superior to what was seen in the general population. The decrease in mortality was greatest for deaths from myocardial infarction, venous thromboembolism, pneumonia, and stroke. Patients tended to have more comorbidity over time and the length of hospital stay roughly halved. Conclusion: Mortality rates following elective THR and TKR have decreased substantially since the early 90s, despite operated patients having more comorbidity. These findings are reassuring for patients undergoing elective THR or TKR. © 2013 American College of Rheumatology.