Knee osteoarthritis (KOA) is a degenerative joint disease characterized by articular cartilage degeneration, cartilage exfoliation, osteophyte formation, and synovitis. It seriously affects the knee joint function and quality of life of patients. Total knee arthroplasty is now the most frequently used therapy for end-stage knee arthritis because it can successfully modify the line of lower extremities, restore knee joint function, alleviate pain, and enhance patients’ quality of life; nevertheless, it may cause significant trauma and bleeding. It can easily lead to infection and anemia. In this study, the control group chose total knee arthroplasty and the observation group chose total knee arthroplasty combined with PRP. The results showed that the knee joint function score, visual analog score, blood transfusion, total blood loss, total postoperative drainage, and complications in the observation group were superior to those in the control group. Total knee arthroplasty takes a long time and needs a lot of soft tissue incision, which leads to a lot of blood loss and can cause a variety of complications. Gel has been shown in studies to successfully decrease blood loss during and after total knee arthroplasty, enhance knee joint function recovery, and improve patient quality of life. In this paper, the complications and causes of knee osteoarthritis after total knee arthroplasty were studied. Combined with comprehensive nursing intervention for postoperative recovery, it helps to improve the formation of thrombin and calcium ion, which can effectively reduce blood loss, relieve pain, and promote the recovery of knee joint function. This study analyzed the application of total knee arthroplasty combined with gel in the treatment of knee osteoarthritis.