The Influence of Sepsis on the Molecular Structure of Bones: A Fourier Transform Infrared Spectroscopy Study

Fourier transform infrared spectroscopy was used to evaluate the molecular structure of bone tissues of patients who underwent revision of total hip and shoulder arthroplasty. The intensity increase of the spectral bands in the region of 3000-2850 cm-1 provided information about the increase of the lipophilic environment, which supported the formation of aggregates and amyloid protein formation. The appearance and the intensity increase of the "marker band" at 1744 cm-1 suggested protein peroxidation and inflammation progression. The shift of the amide I and amide II absorption bands from 1650 cm-1 and 1550 cm-1, respectively, to lower frequencies was related to changes of collagen conformation structure from α-helix to β-sheet and random coil. The appearance and shifts of the new bands in the region 1200-900 cm-1 were related with the increasing of glycosylation upon inflammation. Important was also the disappearance of the hydroxyapatite vPO43- absorption bands at the spectral regions 1200-900 cm-1 and 550-650 cm-1 indicated the osteolysis development. Moreover, the formation of corrosive metallic implants confirmed the effect of oxidative stress on the development of periprosthetic joint infection.