Review Question - QID 212960

The patient has several medical comorbidities and is presenting with a chronic prosthetic joint infection with a virulent organism (MRSA). The best treatment option at this time would be a two-stage revision arthroplasty.

Chronic prosthetic joint infections occur greater than 3-6 weeks from surgery and result in biofilm formation over the prosthesis, making antibiotic treatment alone ineffective for infection eradication. Diagnosis is based on the MSIS criteria, with chronic infections being suggested with CRP greater than 10, ESR greater than 30, and synovial WBCs greater than 1,100. Two-stage revision arthroplasty is the current gold standard in the United States for treating chronic prosthetic joint infections.

Kuzyk et al. 2014 reviewed two-stage revision arthroplasty for chronic periprosthetic joint infections. The authors stated that there is no consensus on laboratory and histology criteria to confirm eradication prior to proceeding with the second stage. The authors recommend holding IV antibiotics for two weeks and repeated inflammatory markers to evaluate whether to proceed with the second stage and to perform frozen section at the time of the procedure.

Nguyen et al. 2016 reviewed one-stage revision arthroplasty for the treatment of periprosthetic joint infections. The authors reported that in select patients, one-stage revision arthroplasty can have equal if not better outcomes compared to two-stage revision with less surgical morbidity and improved functional outcomes. They concluded that one-stage revision arthroplasty can be successful in patients that are not immunocompromised, minimal medical comorbidities, known pathogen prior to surgery, non-polymicrobial, no virulent pathogen (MRSA), and with good soft tissue coverage.

Figures A and B demonstrate AP and lateral radiographs of the right with radiolucencies present around the tibial and femoral prosthesis. Illustration A demonstrates a treatment algorithm proposed by Kuzyk et al. for proceeding with the second stage of a two-stage revision. Illustration B demonstrates the Musculoskeletal Infection Society diagnostic criteria for a prosthetic joint infection. Illustration C depicts specific lab values for diagnosing a prosthetic joint infection.

Incorrect Answers:
Answer 1: A knee fusion is an option after the infection has been eradicated, however, this is unfavorable as it would leave the patient with a stiff extremity.
Answer 2: Long term antibiotic suppression is an option for patients that are unable or unwilling to tolerate multiple procedures.
Answer 3: One stage revision arthroplasty is an option in the right candidate, but this patient is infected with a virulent organism making one-stage unlikely to succeed.
Answer 5: An above knee amputation is a viable option for patients that have failed to eradicate the infection after several surgical attempts with IV antibiotics. However, this is not warranted as initial therapy.