Is there concordance between bone and tendon cultures in patients with foot tissue loss?

BACKGROUND: Deep infections of the extremities are a challenge that threaten limb salvage. OBJECTIVES: To investigate whether the results of bone and deep tissue cultures from patients with trophic limb ulcers coincide. METHODS: A retrospective study was conducted with data from 54 patients with deep trophic limb ulcers admitted to the Complexo Hospitalar Universitário Professor Edgard Santos, Salvador (BA), Brazil. The study analyzed all patients for whom cultures of material from foot wounds in patients with tissue loss had been performed using two specimen types: bone and fragments of deep tendon. The study analyzed concordance between the two sample types and total number of microorganisms and numbers of microorganisms by Gram staining in both samples. RESULTS: The mean age of the 54 patients in the sample was 63.6 years, 80% had PAOD, 70% were diabetic, and 72% were hypertensive. Analysis of the cultures showed that 28 (52%) pairs of samples from the 54 patients exhibited complete concordance, with the same microorganisms grown from fragments of deep tendon and bone. There was partial disagreement in 13 samples (24%) and total disagreement in 13 (24%). On average, 1.62 microorganisms were isolated from deep tendon fragments and 1.72 were isolated from bone samples. Analyzing Gram-positive microorganisms separately, the mean number of species grown was 0.48 for tendon cultures and 0.44 for bone cultures. In contrast, the mean number of Gram-negative microorganisms isolated was 1.14 for tendon samples and 1.27 for bone samples. CONCLUSIONS: Around half of the patients with foot tissue loss had bone and tendon cultures that coincided exactly.