Incidence of infection and analysis of contributing factors in revision joint arthroplasty over a two‐year period

Abstract

AbstractThis study examined the incidence of infection and the contributing factors in 166 patients undergoing total joint revision surgery. Of these 32 (19%) had organisms grown from material taken at the local site at the time of revision surgery. Six of the culture‐negative patients were clinically suspected of having an infection. With the inclusion of these six, the total incidence of infection in these revision patients was 23%. This is not the incidence of infection in total joint surgery. This is the incidence of infection in patients undergoing revision surgery for whatever reason. The cause of infection in 53% of the cases was either Staphylococcus aureus or coagulase‐negative Staphylococci. The Gram‐negative bacteria were implicated in only five (15%) of the cases. Many of these infections (31%) were in patients who had had the implant for greater than 7 years. Only 15% of the infections were in patients who had the implant for less than 6 months with an additional 9% being revised in the first year. There were no clinical symptoms or underlying conditions, including allergy, that distinguished the infected from the noninfected group. The infection rate was somewhat higher with the cobalt chromium alloys, somewhat less in the uncemented devices, and somewhat higher in the patients with total knee replacements than those with total hip replacements. The histopathologic analysis revealed that the presence of polymorphonuclear leukocytes (PMNS) was correlated with infection, but most patients with infection had lymphocytes rather than PMNS indicative of a chronic infection. Thus the diagnosis of infection on the basis of histopathology needs to be carefully evaluated. The presence of PMNS is diagnostic for infection, but has a high number of false negatives. The histopathologic data and the data on implantation time indicate that most of these infections are chronic infections. © 1994 John Wiley & Sons, Inc.