A Novel Spacer Device for Treatment of Perimegaprosthetic Infections in Bone Tumor Surgeries Around the Knee

Abstract

Background: Megaprosthesis constitutes the mainstay of limb salvage after bone tumor surgery, and the rate of perimegaprosthetic infection is relatively high. Although the ideal management of perimegaprosthetic infection is 2-stage revision, the ideal antibiotic spacer device is lacking. Methods: We designed a novel spacer device unique to this situation. It is a modular device made of titanium with variable size of the components. This customizes the spacer specific to the situation on the basis of the length of medullary canal and the size of the defect. Antibiotic-impregnated bone cement introduced into the medullary canal on both sides and at the site of the defect provides excellent stability and ability to weight-bear. Modularity ensures that components can be easily assembled and removed at the time of revision surgery. As a proof of concept, we used this spacer in 2 patients with perimegaprosthetic infection as a bridge between debridement and definitive reconstruction. Results: Both patients were young male individuals with multiple episodes of perimegaprosthetic infection in the past. Debridement resulted in defect of 24 and 28 cm, respectively. Both of them had spacer application along with antibiotic bone cement. Infection could be well controlled, and patients could be made to fully weight-bear with the spacer. Successful revision prostheses could be implanted 12 and 18 months from index surgery with no relapse of infection at 2-year follow-up. Conclusion: We recommend this novel spacer device to ensure stability and functionality in 2-stage revision surgeries of infected megaprostheses.