Value of digital telethermography for the diagnosis of septic knee prosthesis: a prospective cohort study

Background Diagnosis of peri-prosthetic infection remains challenging, often requiring a combination of different tests. Methods In this prospective, case–control study, the diagnostic accuracy of telethermography was evaluated in a group of seventy patients who had had a total knee replacement and were undergoing a reoperation because of infection or another implant-related problem, after a minimum of one year from implant. Results An average differential temperature of the affected versus not affected knee of 1.9°C was observed in infected prosthesis, compared to 0.3°C in aseptic failures. Considering a normal reference value equal or less than 1.0°C, telethermography showed an accuracy, sensitivity, specificity, positive and negative predictive value of, respectively: 0.90, 0.89, 0.91, 0.91, 0.88. Conclusions Digital telethermography is a reliable option for diagnosing peri-prosthetic knee infection.