One hundred sixty four patients with end-stage knee osteoarthritis undergoing primary unilateral total knee arthroplasty were randomized to receive either conventional follow-up with a standardized home-based exercise prescription (control, n = 82) or the same exercise prescription supported by a cloud-based follow-up system delivering multimedia exercise guidance and interactive communication (intervention, n = 82). The primary outcome of interest was knee function measured by the WOMAC score. Secondary outcomes included health-related quality of life (SF-36), adherence to rehabilitation exercises, and total follow-up costs. Outcomes were assessed preoperatively and at 2, 4, and 12 weeks postoperatively (WOMAC at 2, 4, 12 weeks; SF-36 at 4 and 12 weeks; adherence at 2, 4, 12 weeks; costs at 12 weeks). Overall, the results of the study revealed that the cloud-based follow-up program produced better early (≤4 weeks) knee function, higher quality of life at 4 weeks, and greater short-term adherence to exercises, while reducing total follow-up costs; by 12 weeks, clinical outcomes converged between groups. These findings suggest that integrating cloud-based follow-up with structured exercise prescriptions may enhance early recovery and cost-effectiveness of home-based rehabilitation after TKA.