Abstract
INTRODUCTION AND IMPORTANCE: Total hip arthroplasty (THA) is a widely performed procedure with excellent outcomes, though complications such as infection, osteolysis, and rare metallosis may occur. Metallosis results from metallic debris deposition in periprosthetic tissues and is usually linked to metal-on-metal implants, but can also develop with nonmetallic prostheses. CASE PRESENTATION: We describe a 59-year-old male with a right uncemented metal-on-polyethylene THA who developed persistent hip pain, clicking, and functional decline. The laboratory workup indicated high C-reactive protein levels, while imaging showed acetabular loosening with the classic "cloud" and "bubble" appearance. Staphylococcus aureus was identified by culture after joint aspiration revealed black fluid. The patient had prosthesis removal, thorough debridement, and the insertion of an antibiotic spacer, followed by targeted antibiotic treatment, which resulted in clinical and biochemical improvements. CLINICAL DISCUSSION: This case highlights the unusual coexistence of metallosis and prosthetic joint infection in a nonmetallic implant. It emphasizes the diagnostic value of imaging and aspiration, as well as the need for immediate surgical management. CONCLUSION: Metallosis, albeit rare, should be evaluated in patients who report prolonged discomfort following THA, regardless of prosthesis type.