Preoperative physical function has been shown to predict postoperative outcomes, and exercise can help enhance it. However, people with KOA find it difficult to exercise on land because to discomfort and stiffness, but aquatic exercise is more tolerated. We hypothesized that preoperative water exercise to increase physical function would lead to better postoperative outcomes following total knee arthroplasty (TKA). We included 50 patients who were scheduled for elective TKA in 4-8 weeks and scored at or below the 50th percentile on the mobility assessment measure (MAT-SF). For measuring the research study used Smart PLS software and generated results included descriptive, correlation also that explain the smart PLS Algorithm Model. All enrolled participants were evaluated for 1) clinical osteoarthritis symptom severity using the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), 2) physical function using the Short Physical Performance Battery (SPPB) etc. AEI sessions lasted 60 minutes, three times a week, for 4-8 weeks. Participants in both groups were examined one week before and four weeks after their procedure. A 4–8-week aquatic exercise intervention improved functional outcomes, depression, and cognition in elderly individuals receiving TKA. Bigger research is needed to investigate the impact of water exercise on clinical and functional outcomes following TKA. Overall research found directly effect of aquatic exercise on postoperative recovery also that mobility in elderly patients.