Progressive Structural Failure in Complex Prosthetic Joint Infection Followed by Amputation

Background: Prosthetic joint infections (PJI) are complex complications of arthroplasty. Detailed sequential polymicrobial infection during long clinical courses, with multiple interventions and sustained antibiotic pressure, has been described sparingly. Methods: We present a case of a 78-year-old woman with various comorbidities, including type 2 diabetes mellitus and grade I obesity (body mass index of 31.6), who developed an early PJI after total knee arthroplasty, followed by amputation. Results: Despite serial surgical procedures and antimicrobial therapies, the patient had progressive structural failure in a complex polymicrobial PJI. Therefore, above-knee amputation was required due to reconstructive failure. During the 23-month clinical course, infections caused by six distinct bacteria, some of which were resistant and associated with intramedullary osteomyelitis, were reported at different stages. Conclusions: This case illustrates the evolution and challenging complications of a rare yet dynamic process that developed under selective surgical and antimicrobial pressure. Early recognition of host, tissue, and microbial factors is crucial to achieving optimal PJI outcomes.