Talonavicular joint arthritis is a great concern after ankle fusion. Although arthrodesis is the gold standard treatment for this complication, it could initiate a vicious cycle of further adjacent joint arthritis. An alternative that may delay or eliminate the need for arthrodesis is excision arthroplasty; however, there are only a few reports on its application on a talonavicular joint. We report 3 cases of excision arthroplasty with interpositional Achilles tendon autograft for the treatment of end-stage talonavicular osteoarthritis in low-demand elderly patients. In 1 patient, excision arthroplasty was performed after tibiotalocalcaneal arthrodesis, and in 2 patients, it was performed after tibiotalar arthrodesis, in which the subtalar joints were also damaged and fused simultaneously on performance of the interpositional arthroplasty of the talonavicular joint. In all cases, pain relief and functional activities of daily living improvement were achieved with this procedure. At a minimum follow-up of 1 year, no patient reported adjacent joint symptoms or flatfoot progression. These cases show that interpositional arthroplasty with Achilles tendon autograft is an effective treatment for end-stage talonavicular arthritis in patients with fused ankle and subtalar joints. This procedure was helpful in relieving pain and improving activities of daily living function in low-demand elderly patients with the preservation of movement of the talonavicular joint. Autograft was considered to be superior to other grafts with respect to availability, graft rejection, or allergy development. Fused subtalar joint resolved the concerning issues, such as flatfoot progression and muscular weakness of ankle plantar flexion, associated with this procedure.