Does age influence management of patients with prosthetic joint infections?

Patients aged ≥75 years with a first prosthetic joint infection following hip or knee arthroplasty have similar presentations and management as their younger counterparts (aged <75 years), according to a study. However, cardiac abnormalities and mortality at 1 year are higher in older patients.

“In our single-centre study, patients with first prosthetic joint infection had similar management, regardless of age,” the researchers said. “We identified cardiac history as one of the host factors for prosthetic joint infection most seen in patients ≥75 years of age.”

Ninety-eight patients aged <75 (n=63) or ≥75 years (n=35) with first prosthetic joint infection of the hip or knee admitted to a tertiary medical centre between September 2017 and December 2019 were included in this study. The researchers compared clinical characteristics, management, and mortality between the two cohorts.

As a result, older patients and their younger counterparts showed similar aetiology, culture-directed therapy, antibiotic suppression, and length of stay. Likewise, no between-group difference was seen in surgical management, which was performed in about 97 percent of patients in both cohorts. [Am J Med 2023;136:100-107]

On the other hand, patients ≥75 years of age had higher prevalence of arrhythmia and heart failure, but they were less likely to be readmitted due to prosthetic joint infection (p=0.005). Although deaths within 1 year of diagnosis were rare (n=4, 4.1 percent), they occurred more often among older patients, and the most frequent cause was sepsis.

“We had anticipated higher readmission rates in older patients due to side effects of medication, issues with adherence, refractory infections, and surgical complications,” the researchers said. “It is possible that because patients aged ≥75 had lower smoking rates and obesity, they experienced better wound healing and fewer postoperative complications.”

Predictors of infection

Earlier studies identified the following potential risk factors for infection: smoking, obesity, diabetes, and rheumatologic disease. The current study found smoking, body mass index ≥30 kg/m², and rheumatologic disease to be more common among patients aged <75 years. [Clin Microbiol Rev 2014;27:302-345; Infection 2015;43:629-637; Infection 2015;43:629-637; BMC Musculoskelet Disord 2021;22:776]

“We found no differences between groups in terms of aetiology and management of infection,” the researchers said. “Specifically, time from arthroplasty to diagnosis, time from diagnosis to surgery, and length of hospitalization were similar in the groups.”

Prosthetic joint infection is usually treated by removing the infected hardware, culture-directed antibiotics, and subsequent revision arthroplasty. [N Engl J Med 2004;351:1645-1654; Clin Microbiol Rev 2014;27:302-345; Clin Infect Dis 2013;56:1-10; Infection 2015;43:629-637; Infect Dis Clin North Am 2018;32:843-859]

Attempt at joint salvage, however, is often reserved for patients with acute infection. This procedure normally involves the removal and exchange of the modular polyethylene liner.

“We had hypothesized that the oldest patients might not have been considered good candidates for any type of surgical intervention and that, among patients who did have surgery, a single procedure (debridement and implant retention or single-stage revision) would have been preferred to minimize morbidity of multiple operations,” the researchers said.

“Our data showed that more than 95 percent of the patients in both groups underwent some type of surgical intervention, even the oldest patients, without a difference in the type of surgeries performed between the two groups,” they noted.

Further studies with larger sample sizes and longer follow-up are warranted to validate these findings and explore risk factors and management strategies in older populations, according to the researchers.