Tubercular prosthetic knee joint infection.

This article reports a rare case of late-onset tubercular infection following total knee arthroplasty in a 60-year-old woman who had been treated with a full course of antitubercular therapy for latent tuberculosis almost 25 years ago. Because no clear guidelines exist for optimal management of disease reactivation in the prosthetic knee joint, the authors performed a literature review and attempted to provide a treatment algorithm based on the time of presentation. Two modes of presentation were identified for unsuspected tubercular prosthetic joint infections based on the onset of symptoms and time to diagnosis: an early-onset presentation that occurs within the first 6 to 8 weeks postoperatively and a late-onset presentation that usually manifests after 8 weeks. Early-onset presentations often can be treated with standard antitubercular chemotherapy alone, whereas late-onset presentation may require 2-stage reimplantation under cover of antitubercular medications. This report also highlights the fact that despite adequate treatment of latent tuberculosis, patients may remain at risk of prosthetic joint infection following total knee arthroplasty.