Clinical practice. Infection associated with prosthetic joints

Abstract

A 62-year-old woman with osteoarthritis presents with a 7-month history of progressively worsening left hip pain radiating to the groin, 8 months after undergoing total left-hip arthroplasty. The pain has not responded to nonsteroidal antiinflammatory drugs. Physical examination reveals a sinus tract overlying her left hip. Her leukocyte count is 8000 per cubic millimeter, and the C-reactive protein (CRP) level is 15.5 mg per liter. A radiograph shows loosening of the prosthesis at the bone–cement interface. Synovial-fluid aspirate shows 15×10³ cells per cubic millimeter (89% neutrophils); cultures of an aspirate from the hip grow Staphylococcus epidermidis. How should her case be managed?

Figure 1. Total Arthroplasties Performed and Prosthetic Infections, According to Procedure

Panel A shows the number of total arthroplasties performed from 1990 through 2006. Data are from the Centers for Disease Control and Prevention. Panel B shows the number of prosthetic-joint infections from 1990 through 2004. Data are from Kurtz et al.

Figure 2. Causes of Infection Associated with Prosthetic Joints

A small number of often otherwise nonvirulent bacteria contaminate the implant during surgery and persist as a biofilm despite a functional immune system and antimicrobial treatment. Commonly isolated microorganisms are shown. Unusual organisms that can also cause infection include (but are not limited to) Actinomyces israelii, Aspergillus fumigatus, Histoplasma capsulatum, Sporothrix schenckii, Mycoplasma hominis, Tropheryma whipplei, and mycobacterium (including tuberculosis), brucella, candida, corynebacterium, granulicatella, and abiotrophia species.

Figure 3. Algorithm for the Treatment of Infection Associated with a Prosthetic joint