Küntscher nails with static cement spacer: A simple technique in periprosthetic knee infections with massive bone loss and instability

Background: Two-stage revision for periprosthetic knee infection is challenging in cases of massive bone loss and instability. The present study aims to describe our experience with an alternative technique of reinforced cement spacer, usually necessary in these situations, focusing on its advantages and clinical results. Methods: We retrospectively identified all patients who underwent a two-stage revision for periprosthetic knee infection using two intramedullary Küntscher nails as reinforcement from January 2010 to September 2018. From each medical record, we extracted the type of explanted prosthesis, isolated micro-organism, number of cement spacers before index procedure (and related episodes of spacer dislocation) and final treatment. Results: Twelve patients were identified, mean age of 64.0 years (range 39–85). In four of them, the reinforced spacer was used twice for persistent infection, with a total of 16 procedures performed and no cases of dislocation. Ten patients were finally treated with reimplantation or arthrodesis with intramedullary nails, whereas an above-knee amputation was necessary for two patients. Infection was eradicated in 10 patients out of 12 (83%) at a mean follow up of 34.3 months (range 10–62). Conclusions: This technique is an effective alternative to traditional spacers in cases of massive bone loss, producing a mechanically stable joint and preserving adequate tissue tensions. The construct is technically easy to perform and, not less importantly, to remove during stage 2. Further studies, with larger groups, are necessary to determine its validity.