This chapter explores the intricacies of ankle arthrodesis, with a particular focus on arthroscopic ankle arthrodesis (AAA) as the gold standard treatment for advanced, painful ankle osteoarthritis. The discussion begins by addressing the nature of the problem and the historical context of AAA, emphasizing its effectiveness in treating degenerative ankle disease and improving functional outcomes. The chapter then outlines the indications and contraindications for AAA surgery, highlighting the critical role of soft tissue management and the relative contraindications, such as deformity and poor vascularity. A detailed description of the surgical technique follows, including preoperative planning, patient positioning, and a step-by-step surgical approach. Additionally, postoperative care and various approaches to ankle arthrodesis, including posterior and transfibular methods, are examined. Fixation strategies, including the use of screws and plating, are discussed, alongside key considerations for achieving deformity correction. The chapter concludes with an evaluation of the reliability of open ankle arthrodesis (OAA) and emphasizes the importance of thorough preoperative assessment and meticulous surgical techniques to ensure successful outcomes.