Periprosthetic joint infection of shoulder arthroplasties is one of the most frequent reasons for pain and revision surgery of shoulder arthroplasties. Propionibacterium acnes is one of the commonest microorganisms causing periprosthetic joint infection in shoulder arthroplasties. It is difficult to detect this slow growing microorganism. This paper gives an overview of the different diagnostic methods. A combination of unspecific and specific tests (detection of microorganism and sensitivity to antibiotics) is helpful in identifying a periprosthetic shoulder infection. Aspiration of the joint can combine different unspecific and specific tests. In patients with punctio sicca and suspected periprosthetic joint infection, we recommend biopsy of periprosthetic tissue.
