Abstract
Background and Purpose: The purpose of the present study was to assess the risk for revision due to deep infection for primary uncemented total hip arthroplasties (THAs) reported to the Norwegian Arthroplasty Register (NAR) over the period 1987–2007.
Methods: All primary uncemented THAs reported to NAR from the period 1987–2007 were studied. Adjusted Cox regression analyses with first revision due to deep infection as the end-point were performed. Changes in the revision rate as a function of year of operation were investigated, as was impact of risk factors (gender, age, type of diagnosis, duration of surgery, operation room ventilation and systemic antibiotic prophylaxis) on risk for revision due to deep infection.
Results: 14,348 primary uncemented THAs met the inclusion criteria. 97 THAs had been revised due to deep infection (5-year survival 99.56). Risk for revision due to deep infection increased through the period studied. Compared to the uncemented THAs implanted 1987–1992, the risk for revision due to infection was 1.2 times higher (95%CI 0.6–2.4, p=0.6) for those implanted 1993–1997, 1.4 times (95%CI 0.7–2.9, p=0.3) for 1998–2002, and 5.3 times (95%CI 2.6–10.7, p=< 0.001) for 2003–2007. The increase in risk for revision due to infection for primary uncemented THAs was most pronounced after the year 2000. No risk factor registered had any statistically significant impact on risk for revision due to infection in this study.
Interpretation: The results of this study indicate an increase in incidence of deep infection after uncemented THAs during the period 1987–2007. Concomitant changes in confounding factors, however, complicate the interpretation of these results.
Correspondence should be addressed to Vienna Medical Academy, Alser Strasse 4, A-1090 Vienna, Austria. Phone: +43 1 4051383 0, Fax: +43 1 4078274, Email: ebjis2009@medacad.org
