Older adults are at higher risk of falling following total knee arthroplasty (TKA). However, it remains unclear how long a full recovery of the balance control during gait post-TKA will take. The current study aimed to bridge this knowledge gap via long-term follow-up gait analyses. Twelve older adults with severe bilateral medial knee osteoarthritis (OA) before, 3 and 12 months after TKA, and twelve healthy controls were evaluated for their balance control during level walking, in terms of the inclination angle (IA) of the center of pressure to center of mass vector, and the rate of change of IA (RCIA). The patients before TKA showed significantly increased sagittal IA but decreased RCIA throughout the gait cycle (p < 0.04) compared to controls, suggesting a compromised balance control. Three months post-TKA, deviations in IA remained, although those in RCIA were improved to normal. One-year post-TKA, no significant differences were found in any of the IA- and RCIA-related variables between patient and Control groups. The results show that TKA surgery was effective in reducing the deviations in the center of mass-center of pressure control in patients with severe bilateral knee OA, and full recovery of balance control can be expected 1 year after surgery.