Fig. 3A–D.

This drawing illustrates the injection portals (A) that are outside the skin, the fibrous cuffs that are approximately 5 mm deep to the dermis (B), the catheters inside the synovial cavity of the knee (C), and outflow of the antibiotic through the synovial membrane and into the regional veins (D). The fibrous cuffs seal the catheters so that contaminants do not enter the knee and joint fluid does not leak out.