Abstract:[Objective] To evaluate the clinical outcome of accessory navicular fusion and posterior tibial tendon reattachment for adulttype II painful accessory navicular syndrome. [Methods] A retrospective study was done on 10 adult patients who had type II painful acces-sory navicular syndrome treated with abovesaid surgical procedures in the our department from March 2021 to June 2023, including 3males and 7 females with an average age of (40.2±4.4) years. The clinical and imaging data were evaluated. [Results] All patients were oper-ated on successfully completed, with operation time of (54.2±4.4) min, incision length of (5.1±0.9) cm, intraoperative blood loss of (17.0±8.2) mL, intraoperative fluoroscopy times of (1.9±0.8) times, ambulation time of (5.2±0.9) weeks, and the full weight-bearing activity time of(8.5±1.1) weeks. All patients were followed up for an average of (13.5±1.9) months. With time preoperatively, 3 months after surgery and atthe last follow-up, the VAS score [(6.1±1.0), (1.3±0.7), (1.4±0.8), P＜0.001] and AOFAS score [(55.6±7.1), (87.5±4.6), (90.0±0.5), P＜0.001]improved significantly. In term of imaging, there was no significant change in calcaneal inclination angle after operation. Fusion betweenthe navicular and accessory navicular was radiographically noted in a mean of (16.2±3.5) weeks. [Conclusion] The modified navicular fu-sion and posterior tibial tendon reattachment are an effective surgical method for the treatment of adult type II painful accessory navicularsyndrome.