Incidence, Secular Trends, and Outcomes of Prosthetic Joint Infection: A Population-Based Study, Olmsted County, Minnesota, 1969–2007

Abstract

Context The epidemiology of prosthetic joint infection (PJI) in a population based cohort has not been studied in the United States. Objectives To provide an accurate assessment of the true incidence, secular trends, clinical manifestations, microbiology and treatment outcomes of PJI in a population based cohort. Design Historical cohort study Setting Olmsted County, Minnesota, United States of America. Participants Residents who underwent total knee arthroplasty (TKA) or total hip arthroplasty (THA) between 1/ 1/ 1969 and 12/ 31/ 2007. Methods Incidence rates and trends in PJI were assessed using the Kaplan Meier method and log-rank test, as were treatment outcomes among PJI cases. Results 7375 THA or TKA were implanted in residents of Olmsted County during the study period. Seventy five discrete joints in 70 individuals developed PJI, during a mean(+/− SD) follow up of 6.8 (+/− 6.1) years. The cumulative incidence of PJI was 0.5%, 0.8% and 1.4% after 1, 5 and 10 years following arthroplasty, respectively. Overall, the rate of survival free of clinical failure after treatment of PJI was 76.8 % ( 95% CI: 64.3 – 85.2) and 65.2 % ( 95% CI: 33.1 – 76.2) at 3 years and 5 years, respectively. The incidence and treatment outcomes did not significantly differ by decade of implantation, patient age at implantation, gender or joint location. Conclusions The incidence of PJI is relatively low in a population based cohort, and is a function of age of the prosthesis. Incidence trends and outcomes have not significantly changed over the past forty years.

Prosthetic Joint Infection

“…The greatest risk period was the first 2 years, during which time 60 to 70% of infections occurred, a finding that has been observed in other studies (8,9). The authors of the population-based study hypothesized that the stability in the incidence over the nearly 40-year time span was due to increased patient morbidity and risk factors for infection, counterbalanced by improvements in aseptic techniques, surgical skills, and infection prevention and control measures (7). While it is unclear if the incidence per person-joint-years is increasing or not, the absolute number of PJI cases will surely increase due to the increasing number of primary implantations being performed and the cumulative number of arthroplasties that remain in place.…”

“…For example, a patient with multiple findings consistent with PJI, such as pain, effusion, periarticular warmth or erythema, and fever, may be considered to have a pretest probability of PJI exceeding 20%. The diagnostic algorithm for this patient may be markedly different from those for patients presenting with pain as the only potential manifestation of infection, where the pretest probability may be closer to the population-based risk of 0.5 to 1.5% (7). Unfortunately, there have been no large, well-performed studies comparing the abilities of different clinical findings to predict PJI.…”

“…Similarly, the Nordic Arthroplasty Register Association found an increase in the cumulative 5-year revision rate for infection in hip arthroplasties, rising from 0.46% during the period from 1995 to 1999 to 0.71% during 2005 to 2009 (6). However, a smaller population-based study from 1969 to 2007 using the Rochester Epidemiology Project to examine 75 PJIs in 7,367 joints did not find an increase over the duration of the study (7). The cumulative incidences of infection were 0.5, 0.8, and 1.4% at 1, 5, and 10 years, respectively, after primary hip or knee arthroplasty, with the overall unadjusted incidence rate, determined by using a standardized denominator, being 1.5 infections per 1,000 personjoint-years.…”

“…Commonly reported signs or symptoms of PJI include pain, joint swelling or effusion, erythema or warmth around the joint, fever, drainage, or the presence of a sinus tract communicating with the arthroplasty (7,(57)(58)(59). The presence of a sinus tract is considered by most investigators to be definitive evidence of PJI, leading to its inclusion as definitive evidence of PJI in several consensus documents (60)(61)(62), as discussed in Diagnosis, below.…”

“…In general, pain seems to be the most frequently reported clinical manifestation, with case series reporting between 79 and 100% of patients with this finding (7,58,(63)(64)(65)(66). However, a study by Peel and colleagues found that pain was present in only 42% of patients, while drainage from the surgical wound was the most frequent finding in 72% of patients (57).…”