Abstract: BACKGROUND: Previous studies have reported that tibiotalocalcaneal arthrodesis via fibular flap support combined with hollow screw has a definite effect in the treatment of ankle osteoarthritis, but the fibular flap does not have blood supply, which affects the recovery of local blood circulation to a certain extent. In this study, the tibiotalocalcaneal arthrodesis via fibular portal with blood supplied fibular flap combined with hollow screw was improved by using the good blood supply of the distal fibula, and the clinical effect of the improved operation in the treatment of ankle osteoarthritis was discussed. 
OBJECTIVE: To investigate the biomechanical effects on affected limbs and the clinical effect of tibiotalocalcaneal arthrodesis via fibular portal with blood supplied fibular flap combined with hollow screw for ankle osteoarthritis.
METHODS: From January 2018 to October 2020, 30 patients with severe ankle osteoarthritis in Dalian No. 2 People’s Hospital were included in this study, and all patients underwent tibiotalocalcaneal arthrodesis via fibular portal with blood supplied fibular flap combined with hollow screws. After 12 months of follow-up, local blood circulation of distal fibula and the stage I healing of the incision were observed, and the ankle CT was reviewed postoperatively to evaluate the time of bone healing. The postoperative recovery was evaluated by gait analyzer and plantar pressure measurement system and the postoperative complications were mastered.
RESULTS AND CONCLUSION: (1) All patients were followed up for 12 months after operation, and no case of loss to follow-up was found. Postoperative Doppler angiography showed that the vascular pedicle of the affected limb and perforating branches of the posterior peroneal artery were accompanied by venous anastomosis; local blood circulation was good; and the incisions were all in stage I healing. (2) After surgery, the ankle CT examination showed that the bone healing time at the fusion site was 8-13 weeks, with a mean of (10.70±2.13) weeks. (3) At 3 months after surgery, the patients’ step length, step speed and step frequency were significantly higher than those before surgery (P < 0.05). (4) According to the measurement of plantar pressure measurement system, the pressure values of the second metatarsal area, the third metatarsal area, the fourth metatarsal area, the middle foot, the medial heel, the lateral heel and the whole plantar of the affected side were significantly lower than the preoperative values during the natural walking at 6 months after surgery (P < 0.05). (5) During the postoperative follow-up, one case showed sural nerve injury symptoms, which disappeared after symptomatic treatment. (6) The excellent and good rate of ankle function recovery was 100%. (7) Above results have confirmed that the treatment of ankle osteoarthritis by tibiotalocalcaneal arthrodesis with blood supplied fibula flap combined with hollow screw through fibula portal approach can effectively improve local blood circulation, improve fusion effect and promote the recovery of ankle function of the affected limb, which has an important clinical significance. 

Key words: fibula flap with blood supply, hollow screw, tibiotalocalcaneal arthrodesis, ankle, osteoarthritis, local blood circulation, bone healing, plantar pressure