To explore the clinical efficacy of autologous vascularized fibula flap transplantation for the treatment of infectious femoral bone defects.

A retrospective analysis was conducted on the clinical data of 11 patients with infectious femoral bone defects treated in the Department of Orthopedic Trauma， Norinco General Hospital from January 2018 to January 2022. There were 8 males and 3 females， with an average age of （34.0±4.5） years and an average bone defect length of （9.5±1.7） cm. During surgery， after thorough debridement of the bone defect ends， the femur was fixed. An autologous vascularized fibula composite tissue flap was harvested for one-stage reconstruction. The vascular pedicle of the vascularized fibula was anastomosed to the recipient vessels via end-to-side technique after isolating and trimming the vascularized fibula. Among them， 5 cases were repaired with a single fibula graft， and 6 cases were repaired with a two-segment fibula graft， with an average transplanted fibula length of （14.5±3.2） cm. The vascularized fibula was fixed with plates or an external fixator. Postoperatively， routine anti-infection， anticoagulation， and antivasospasm treatments were administered （anti-infection treatment course lasted 4-6 weeks， and anticoagulation and antivasospasm treatments lasted for 2 weeks）. Infection control and vascularized fibula survival were closely observed. The healing status at the junction of the vascularized fibula and the recipient site was evaluated by follow-up radiological examinations during reconsultations. Patients were instructed to perform lower limb functional exercises， and the healing conditions of the affected limb and donor site， as well as limb function， were evaluated using the Enneking score， Baird-Jackson ankle function score， association for the study and application of the method of Ilizarov （ASAMI） criteria， and lower extremity functional scale （LEFS） score.

All 11 patients were followed up， with an average follow-up time of （24.5±12.8） months. All wounds healed primarily without infection recurrence， all vascularized fibula survived with no vascular crisis observed， and there was no significant functional impairment at the donor sites. All transplanted vascularized fibula achieved stable bony union， without bone resorption， osteosclerosis， or refracture. The average time to bony union was （5.5±1.2） months. At 12 months postoperatively， the average Enneking score of the affected limb was （24.0±3.3） points， the average Enneking score of the donor site was （27.2±1.1） points， and the average Baird-Jackson ankle function score of the donor site was （95.5±1.6） points. At the final follow-up， ASAMI criteria assessment of the affected limb showed excellent bone results in all 11 patients， with 7 cases of excellent functional results and 4 cases of good functional results. The average LEFS score of the affected limb was （75.5±2.2） points.

The application of vascularized fibula transplantation and vascular reconstruction helps improve local blood supply and control infection， can effectively repair large-scale infectious femoral bone defects， and improve the bone healing rate. It is an effective clinical treatment for this type of disease.