We report a 68-year-old woman with chronic periprosthetic joint infection (PJI) of the acetabular component after left total hip arthroplasty (2001) and multiple acetabular revisions, most recently with a Kerboull reinforcement device and cemented cup (2023), resulting in severe acetabular bone loss (Paprosky IIIB). Applying the EBJIS definition, infection was classified as "likely" despite negative cultures, and a two-stage revision was undertaken. The first stage (February 2025) comprised explantation, extensive debridement and a vancomycin/gentamicin-loaded calcium sulfate spacer; all intraoperative samples were culture-negative. After a 12-month interval, reimplantation (February 2026) was performed with a porous acetabular augment, cementless revision shell and revision stem. Intraoperative cultures isolated Staphylococcus capitis, treated with two weeks of intravenous vancomycin followed by six weeks of oral cotrimoxazole. At six months the patient remains infection-free with a stable reconstruction. Culture-negativity does not exclude PJI, and modern revision systems allow stable fixation even in massive acetabular defects.