Abstract
Two-stage exchange has been the gold standard in North America for the treatment of infected knee replacements. The choice of static versus articulated spacers has been debated for a number of years.
At our institution our choice of spacer for 2-stage exchanges is an articulated spacer. This allows motion between stages which facilitates recovery, and makes the second stage technically easier. In a study from our institution we followed 115 infected TKAs treated with the PROSTALAC articulated spacer for 5–9 years. Success for eradication of infection was 88%. With a repeat two-stage, overall infection control was 98%. In addition, we compared functional outcomes to a group of aseptic knee revisions and found no difference in functional outcomes with standard quality of life outcome scores.
While the articulated spacers were our treatment of choice in 2-stage exchange, around 2012 the company that manufactured the PROSTALAC knee components ceased to manufacture them, based on the work of 2 previous studies (Hofmann, Lee). At our institution, we continued to use articulated spacers. However, this was now the so-called Hofmann technique with a new standard femoral component with an all-polyethylene tibia. The only difference from a standard knee revision was no stems and the utilization of high dose antibiotics.
Around the same time as we instituted the change in articulated spacers, results out of Europe were showing promising results with one-stage exchange. In September 2015, our technique was modified to now include an all-polyethylene tibia with a keel. To date we have no results but it is our hope that a high percent of these will achieve stable fixation and will then have a one-stage exchange.
