Section’s osseous slice biopsy during major amputation of lower extremity: preliminary results of prospective cohort study

Abstract

BackgroundThe purpose of this cohort study was to assess the incidence of positive cultures in section’s osseous slice biopsy (SOB) taken at the level of major limb amputation. In case of positive cultures we sought whether the microorganisms present in SOB could take origin from the primary infection site necessitating the amputation. The impact of diabetes on culture results was also investigated.MethodsThis prospective cohort study, which aimed to confirm the results of the pilot study, analysed patients who underwent major limb amputation between 2012 and 2013 in three Lithuanian hospitals. SOBs at the amputation site (surgical bone biopsies) and percutaneous bone biopsies of the distal site were performed simultaneously during limb amputation. Tissue cultures were analysed by microbiologists, and species along with antibiograms were reported. Histopathological assessment and bacterial typing were also evaluated. A positive culture was defined as the identification of at least 1 bacteria not belonging to the skin flora, at least 2 bacteria belonging to the skin flora with the same antibiotic susceptibility profiles or the same bacteria belonging to the skin flora in two different sites. Fisher’s exact test and Student’s test were used to compare the populations and the microbiological results. The statistical significance level was set at P < 0.05.ResultsSixty-nine patients (35 males/34 females), mean age 68.7 (S = 13.6) years, including 21 (30.4 %) with diabetes underwent the major limb amputation. Forty-five amputations (65.2 %) were done above the knee. In total, 207 SOBs and 207 percutaneous distal site biopsies were studied. SOB cultures were positive in 11 (15.9 %) cases. In 5 (45.5 %) cases the same microorganisms were identified in both SOB and distal biopsy cultures. No association between culture results and presence of diabetes was identified.ConclusionsOur results suggest that, independently of the diabetes status, foot infection may silently spread along the bone and can achieve the site of major limb amputation. Additional investigations aiming to confirm this hypothesis and to evaluate a prognostic value are in progress.

Culture Concordance in Different Sections of the Metatarsal Head: Interpretations of Microbiological Results

“…12 Diabetic foot osteomyelitis silently spreads along the bone until it reaches a site of major limb amputation, in 45% of cases. 13 This suggests that there is a high probability of finding microorganisms in cultures from different areas of the same bone, regardless of being covered by healthy tissue. Under this assumption, the selection of PWB or TCB for the diagnosis of osteomyelitis would be irrelevant.…”

Surgical techniques for Bone Biopsy in Diabetic Foot Infection, and association between results and treatment duration

“…In other words, surgery and medical parts of the management of DFO are linked by the results of bone specimen examination. This is true even in case of major amputations since several studies have shown that bone biopsies of the margins of the amputation are positive in a non-neglectable proportion of cases [4,5].…”