Iliopsoas Abscess as the Initial Manifestation of Periprosthetic Hip Joint Infection after Total Hip Arthroplasty: A Case Report and Literature Review.

INTRODUCTION: Iliopsoas abscess complicating chronic periprosthetic joint infection (PJI) after hip arthroplasty is rare but potentially fatal. Because the iliopsoas bursa communicates with the hip joint, infection can track in either direction, delaying diagnosis and sustaining sepsis and treatment failure. Recognizing this presentation early is what allows the underlying prosthetic infection to be identified.

CASE REPORT: An 88-year-old man with a previously well-functioning right total hip arthroplasty presented with a persistent inflammatory syndrome. Contrast-enhanced computed tomography showed a large right iliopsoas abscess. Inflammatory markers stayed elevated despite broad-spectrum antibiotics, and repeat imaging revealed progressive periprosthetic collections with femoral component loosening. Image-guided hip aspiration grew fully susceptible Escherichia coli, confirming chronic PJI. After multidisciplinary discussion, the prosthesis was removed without spacer implantation, given the patient's age, frailty, comorbidities, and limited functional reserve. Source control was achieved, but the post-operative course was complicated by recurrent hematoma, wound breakdown, and progressive functional decline, leading to palliative care. The patient died about 3 months after prosthesis removal.

CONCLUSION: In any patient with an ipsilateral hip prosthesis, an iliopsoas abscess should raise the possibility of occult PJI. A persistent inflammatory syndrome after drainage or antibiotics warrants direct evaluation of the prosthetic joint. Early multidisciplinary management - appropriate imaging, microbiological confirmation, and timely surgery - remains central to a good outcome.