Knee arthrodesis with modular megaprosthesis as salvage procedure for the limb following in a patient with an infected knee tumor prosthesis: A case report.

Introduction: The management of periprosthetic knee infections is a complex event, especially in the context of megaprostheses. An accepted option in these cases is knee arthrodesis, aiming to salvage the limb with acceptable and pain-free functionality. We present a successful case of knee arthrodesis using a hybrid model of modular nail-prosthesis in a patient with massive bone stock loss following the removal of an infected tumor-type prosthesis. Case presentation: A 65-year-old male patient with a chronic periprosthetic infection related to a resection prosthesis implanted 5 years earlier, experiencing knee stiffness and presenting a massive bone stock deficit after prosthesis removal. Initial management involved an osteo-cement spacer and antibiotics, along with a transarticular external fixator. Subsequently, knee arthrodesis was performed using a hybrid model of modular nail-prosthesis, coupled with targeted antibiotic treatment. The arthrodesis was deemed successful, with a pain-free limb and no signs of infection recurrence at the 52-month follow-up. Conclusion: In the scenario of infection and massive bone stock deficit, knee arthrodesis using intramedullary devices such as nails, megaprostheses, or hybrids is an alternative that can be successful if accompanied by appropriate medical-surgical management of the infection. This approach allows for earlier functional recovery compared to other techniques.