The 40% Infection Myth: Why Intramedullary Dowels Might Be Unnecessary

Unpacking the data from 1997 that originally justified dowel use and why modern clinical validation is sorely lacking.

Antibiotic-impregnated intramedullary dowels have historically been advocated and frequently used to facilitate and augment infection eradication via focused delivery of antibiotics into the intramedullary canals of the femur and tibia in periprosthetic knee infections during a 2-stage resection utilizing an antibiotic cement spacer. However, there is little literature on the use and efficacy of antibiotic-eluting intramedullary dowels in periprosthetic joint infection (PJI). There is also no published consensus recommendation on its use, as the topic was not reviewed in the recent International Consensus Meeting on PJI.

Hanssen and Spangehl recommend insertions of intramedullary dowel spacers irrespective of whether the implant has a stem, based on the assumption that around one-third of infected TKAs without stems have extension of the infectious process into the medullary canals of the femur or tibia. Furthermore, they argue that antibiotic dowels, as opposed to antibiotic beads, are easier to remove at reimplantation. Their recommendation was based on the study by McPherson et al., where they found that during resection, the most common site to yield positive operative cultures was from the medullary canal.