Awareness of the role of bacterial biofilm in the pathogenesis of low-grade or chronic infections diagnosed in hip arthroplasty has been on the rise in recent years. The importance of bacterial biofilm for the development of prosthesis failure is probably underestimated, and terms like aseptic loosening, sterile pus and aseptic necrosis are up for revision. The diagnosis of biofilm has been, and still is, difficult, but new molecular biological techniques, alone or in combination with older established ones, have further helped us to uncover lesions, where biofilm is part of the pathology. This article based on a literature search and own observations is primarily focused on newer methods that help us identify the pathology behind infection-based prosthesis failure. We suggest that the fluorescence in situ hybridization technique on carefully selected biopsy material is used in the future to identify live as well as dead bacteria within their environment. The method is quick and sensitive and provides a reliable result with optimal detection rate.