An individual in their mid-60s presented with pain in the area of a hip replacement that had been undertaken 2 years previously. Hip joint aspiration showed an inflammatory exudate with 45 000 leukocytes/μL and a polymorphonuclear granulocyte fraction of 91%. Due to suspected periprosthetic infection, a planned two-stage revision arthroplasty was performed. Intraoperatively, unusual rice grain-sized particles measuring around 2–3 mm in length were noted below a fascia in the articular region. On histology, the “rice grains” originating from the synovium had a fibrillar matrix, sparse thick collagen fibers, and a flat, endothelium-like surface with aggregated granulocytes. The synovial membrane showed high-grade synovialitis consistent with chronic infection, while from a differential diagnostic perspective, wear particle-induced foreign body granuloma was possible. As empiric therapy, ampicillin/sulbactam was administered in combination with vancomycin. The samples revealed Staphylococcus epidermidis infection, upon which treatment was continued with rifampicin and levofloxacin in line with the antibiogram. Tests for mycobacterial infection were negative. On follow-up at 2 months, the individual was free of symptoms.
Figure.
Macro image following lavage
Acknowledgments
Translated from the original German by Christine Rye.
Footnotes
Conflict of interest statement: The authors declare that no conflict of interests exists.