Septic arthritis of the native hip by granulicatella adiacensa case report and literature review

Background: Septic arthritis of the native hip in adults is an infrequent clinical entity, typically occurring at an incidence of 2 to 10 per 100,000 person-years. *Granulicatella adiacens*, a fastidious, facultatively anaerobic gram-positive coccus and commensal of the oral flora, is rarely implicated in musculoskeletal infections, with most reported cases involving endocarditis or prosthetic joint infections.

Objective: This report describes a unique case of native hip septic arthritis caused by *Granulicatella adiacens* in a 58-year-old female, highlighting the diagnostic challenges and the clinical association with asymptomatic endocarditis.

Key Points: The patient presented with progressive right hip pain following a recent contralateral total hip arthroplasty. Initial magnetic resonance imaging demonstrated joint effusion, and synovial fluid analysis confirmed infection. Although arthroscopic lavage was initially performed, cultures required eight days in enriched media to isolate *Granulicatella adiacens*. Subsequent imaging revealed rapid chondrolysis and subchondral necrosis of the femoral head. Due to extensive articular damage and persistent symptoms, the patient underwent open debridement and the placement of a custom-made, vancomycin-loaded polymethylmethacrylate (PMMA) articulated spacer. Systemic antibiotic therapy was tailored to ceftriaxone and gentamicin based on sensitivity profiles. Concomitant echocardiography identified asymptomatic endocarditis, suggesting hematogenous seeding as the primary mechanism of joint infection.

Conclusion: *Granulicatella adiacens* can cause aggressive native hip destruction requiring staged reconstruction. Clinicians should maintain a high index of suspicion for endocarditis when this fastidious organism is isolated and utilize enriched culture media or molecular techniques to avoid diagnostic delays.