The aim of the study was to compare the efficacy of body stabilization exercises to be applied in addition to conservative physical therapy in patients undergoing total knee arthroplasty. Through this study, we aim to contribute to the literature and the clinic with objective, evidence-based results.

Ostetoarthritis includes the entire joint in a disease process involving the loss of articular cartilage in focal and progressive hyaline, including the increase in osteophytes and the thickness of the subchondral bone. Clinical symptoms of osteoarthritis include joint stiffness, pain, and dysfunction. Knee osteoarthritis causes activity limitation especially in the elderly. American Society of Orthopedic Surgeons, nonsteroidal anti-inflammatory drugs or tramadol in the medical treatment of osteoarthritis; they recommend reinforcement in conservative treatment, low intensity aerobic exercises and neuromuscular training programs. Total knee arthroplasty is preferred for surgical treatment to reduce pain, improve deformity, and improve functional range and range of motion in patients with advanced stage osteoarthritis who do not respond to conservative treatment. Total knee arthroplasty is a surgical procedure in which an artificial joint replaces the damaged knee joint. After knee arthroplasty, there was a decrease in pain, increased range of motion and improved quality of life.

Patients with osteoarthritis have a decrease in proprioceptive sensation due to inflammation in the knee joints and a decrease in knee mechanoreceptors. In addition to this proprioceptive disorder, muscle weakness caused by aging, decreased vision and losses in the central nervous system cause balance effects. This effect of equilibrium increases the fear of falling in individuals and therefore patients tend to move less. Therefore, the resulting inactivity causes a decrease in endurance with muscular force and causes the patients to become more immobile. This is particularly a risk factor for falls in patients with symptomatic lower extremity osteoarthritis and these causes mortality and morbidity.

Lumbopelvic-hip complex or "core" in lumbar vertebrae, pelvis, hip joints and active and passive structures that produce or restrict the movement of these segments. Core stability is associated with lower extremity balance performance. Body stabilization exercises decrease the risk of falling patients and improve their balance. Although stabilization exercises are performed in patients with total prosthesis in the literature, there is no study evaluating the effectiveness of these exercises on balance, functional performance and lumbal lordosis angle.

A prospective, randomized controlled, double-blind clinical study was performed in unilateral total knee arthroplasty (TDP) surgery with a cross-linking, fixed insert, cemented total knee prosthesis and the same type of surgical technique. Ankara Yenimahalle Training and Research Hospital Patients admitted to the Rehabilitation Policlinic will be included in the study. Pre-study volunteers will be randomly assigned into two groups by giving information about the purpose and content of the study. The participants will be evaluated by a blind researcher before, after and 3 months after the treatment and the data obtained from the evaluation results will be analyzed by appropriate statistical methods.

Patients who have at least 80 degrees of knee flexion and full knee extension, who can be mobilized (with ancillary equipment), who can go up and down the stairs, without any infections, will be included in the study after their sutures have been taken. Patients will be randomly divided into two groups as education group and control group. The patients in the control group will undergo a conservative physical therapy program under the supervision of the physiotherapist. The patients in the training group will be given conservative treatment and body stabilization exercise program under the supervision of physiotherapist. The assessments before and after the treatment and after 3 months will be performed by another physiotherapist who does not know what treatment the patients are receiving. Pre-treatment, post-treatment and 3-month post-treatment pain with visual analog scale, joint motion range with goniometer, functional performance with time up and go test, balance with Prokin balance device (ProKin, Tecnobody, Bergamo, Italy), lumbal lordosis angle with Baseline Bubble Inclinometer®, knee functions with Western Ontario and McMaster Universities Osteoarthritis Index, the lower extremity muscle endurance with 30 second chair stand test will be evaluated. Patients in both groups will be treated for a total of 8 weeks 2 days a week.

Inclusion Criteria:

• Patients with Unilateral Total Knee Prosthesis Patients with full knee extension Patients with at least 80 degrees of knee flexion Mobilized (with ancillary equipment) Patients who can climb up and down stairs Patients who are not at risk for cardiac performance in terms of exercise and evaluation tests

Exclusion Criteria:

• Another musculoskeletal problem that may affect lower limb performance A neurological or oncological disease that affects the balance Limb length difference of more than 5 cm before or after surgery Patients with any systemic problem Patients with infection in the knee after surgery