Characteristics and Outcome of Infections Associated with Endoprosthesis Following Resection of Bone Tumors

Background: Endoprosthetic replacement after limb-sal-vage surgery has become a standard option for musculoskel-etal tumor reconstruction. However, infection remains one of the most serious complications, with significant impact on limb survival and functional outcomes. This study aimed to evaluate the characteristics, management strategies, and out-comes of infections following endoprosthesis after bone tumor resection. Aim of Study: To evaluate the incidence, management strategies, and outcomes of postoperative infections following endoprosthetic reconstruction after bone tumor resection, with a focus on infection clearance, limb salvage, and functional results. Patients and Methods: We retrospectively reviewed 216 patientswho underwent limb salvage with modular endopros-thesis following resection of bone tumors between 2003 and 2010 at Nasser Institute, Bone Bank, and Children’s Cancer Hospital, Cairo. Cases complicated by infection (31 patients; 14.4%) were analyzed in detail. Patient demographics, tumor type, surgical site, adjuvant therapy, timing of infection, man-agement modality, and functional outcomes were assessed. Functional outcome was evaluated using the Musculoskeletal Tumor Society (MSTS) score. Results: Of the 31 infected cases (17 males, 14 females; mean age 19.7 years), the most common tumor was osteosar-coma (61.2%), followed by malignant fibrous histiocytoma (9.7%) and Ewing’s sarcoma (6.5%). The most frequent sites were distal femur (45.1%) and proximal tibia (42%). Infection developed early (<3 months) in 14 patients (45.2%), and late (>3 months) in 17 patients (54.8%).Initial management includ-ed antibiotics and debridement, but many cases required staged surgery. Two-stage revision with re-implantation achieved in-fection control in 5 patients (16.1%), while amputation or hip disarticulation was required in 6 patients (19.3%). Conserva-tive treatment with antibiotics alone was successful in a mi-nority of cases. Overall infection eradication and limb salvage were achieved in approximately 64.5% of patients. The mean MSTS functional score in salvaged limbs was 72%. Conclusion: Infection following endoprosthetic recon-struction for bone tumors remains a major complication, with an incidence of 14.4% in our series. Distal femur and proximal tibia resections were the most susceptible sites. While conserv-ative measures may suffice in early low-grade infections, most cases required surgical intervention. Two-stage revision was the most effective limb-salvage strategy, although amputation remained necessary in nearly one-fifth of patients. Strategies to reduce infection risk including improved perioperative pro-tocols and infection-resistant implant coatings are critical to improving long-term outcomes in oncologic endoprosthetic surgery.