[Low-grade-infections after spondylodeses-A chameleon? : Current findings and therapeutic strategies].

backgroundLow-grade infections are caused by low-virulence pathogens. The course of these infections is often mild, which is why they are often delayed or not recognized at all. Chronic infections can lead to osteolysis and implant loosening. The rate of complications requiring revision, such as implant loosening or material failure, is known from the literature. However, the rate of low-grade infections in patients requiring spinal revision surgery remains unclear. PURPOSE: The aim of this review is to present the latest treatment strategies for low-grade infections. The diagnostic and therapeutic options are summarized in the form of algorithms. The aim of this work is to raise an awareness of the possibility of a low-grade infection in patients undergoing spinal revision surgery. MATERIALS AND

methodsReview of the literature

resultsThe detection of low-grade infections is difficult from both a clinical and a radiological point of view. In the event of unexplained implant loosening or failure despite the lack of local inflammatory signs and often normal laboratory parameters, a low-grade infection must be considered. Multiple microbiological sampling must be requested as part of the revision surgery. A histological examination is recommended for all revision surgery, especially if a low-grade infection is suspected. The diagnosis should ideally be completed by sonicating the implants with subsequent microbiological incubation of the preserved samples. If a low-grade infection is suspected, the biofilm-covered implant should be removed or replaced if instability/no fusion is present. The use of topical antibiotics could be useful, but its effectiveness in treating low-grade infections has not yet been sufficiently demonstrated. DISCUSSION: An algorithm for clinical decision-making in terms of diagnostic and therapeutic options is suggested.