Increasing risk of revision due to deep infection after hip arthroplasty: A study on 97,344 primary total hip replacements in the Norwegian Arthroplasty Register from 1987 to 2007

Abstract

Background and purpose Over the decades, improvements in surgery and perioperative routines have reduced the incidence of deep infections after total hip arthroplasty (THA). There is, however, some evidence to suggest that the incidence of infection is increasing again. We assessed the risk of revision due to deep infection for primary THAs reported to the Norwegian Arthroplasty Register (NAR) over the period 19872007. Method We included all primary cemented and uncemented THAs reported to the NAR from September 15, 1987 to January 1, 2008 and performed adjusted Cox regression analyses with the first revision due to deep infection as endpoint. Changes in revision rate as a function of the year of operation were investigated. Results Of the 97,344 primary THAs that met the inclusion criteria, 614 THAs had been revised due to deep infection (5-year survival 99.46%). Risk of revision due to deep infection increased throughout the period studied. Compared to the THAs implanted in 19871992, the risk of revision due to infection was 1.3 times higher (95%CI: 1.01.7) for those implanted in 19931997, 1.5 times (95% CI: 1.22.0) for those implanted in 19982002, and 3.0 times (95% CI: 2.24.0) for those implanted in 20032007. The most pronounced increase in risk of being revised due to deep infection was for the subgroup of uncemented THAs from 20032007, which had an increase of 5 times (95% CI: 2.611) compared to uncemented THAs from 19871992. Interpretation The incidence of deep infection after THA increased during the period 19872007. Concomitant changes in confounding factors, however, complicate the interpretation of the results. © Nordic Orthopedic Federation.