To our knowledge, no studies have been conducted in the literature investigating the relationship between the success of physical therapy programs applied in knee osteoarthritis and patients' pre-treatment expectations. The rationale for this study is to demonstrate the possible relationship between treatment expectations and the benefits seen from conventional physical therapy programs in patients with knee osteoarthritis, and to provide clinicians with a different perspective in knee osteoarthritis treatment planning.

Osteoarthritis, also called degenerative joint disease, primarily occurs in old age, but can also develop after trauma or secondarily to diseases such as rheumatoid arthritis and hemochromatosis. Osteoarthritis is the most common joint disease worldwide. The pathophysiology of osteoarthritis is responsible for the failed repair of joint damage caused by stress initiated by any joint or periarticular tissue abnormality. The most common symptom of osteoarthritis is pain. Factors associated with an increased risk of knee osteoarthritis include advanced age, family history, overweight or obesity, a history of knee trauma, occupational factors, and varus or valgus alignment. Long-term complications of osteoarthritis include decreased physical activity, loss of fitness, sleep disturbances, fatigue, and depression. With the increasing aging population, degenerative joint problems have become a concern for a large part of society. Exercise is a key component in the treatment of this chronic disease, which restricts functionality and reduces quality of life. A systematic review of 54 randomized controlled trials involving a total of 5362 participants showed that different types of exercise improved pain, functionality, and quality of life in knee osteoarthritis. Studies have shown that treatment outcomes are not always similar in patients undergoing similar treatment programs, and that patients' expectations from treatment can also influence results. A systematic literature review on improvement expectations revealed that in 15 out of 16 studies, positive patient expectations were associated with better health outcomes. A recent study in the field of physical therapy also showed that in the treatment of chronic low back pain, high patient expectations were associated with the success of the treatment. Therefore, we planned this study to answer the questions of whether treatment expectations have a predictive effect on the benefits seen from an exercise program in patients with knee osteoarthritis, and whether it is necessary to evaluate the level of expectations when creating a treatment program for patients with knee osteoarthritis.

Inclusion Criteria:

• Agreeing to participate in the study
• Being over 50 years of age
• Having a clinically and radiographically confirmed diagnosis of knee osteoarthritis
• Having grade 2-3-4 knee osteoarthritis according to the Kellgren-Lawrence grading system
• Being literate

Exclusion Criteria:

• Previous knee surgery
• Conditions that prevent exercise (such as incurable malignancy, active systemic infection, non-union fracture)
• Presence of accompanying neurological disease affecting the lower extremity
• Severe cognitive impairment (neuropsychiatric disease or condition that will impede cooperation, such as psychosis, dementia)
• History of having received injections or other procedures to the knee joint or physical therapy within the last 6 months

Patients aged 50 years and older who present with knee pain and are found to have grade 2 or higher gonarthrosis according to the Kellgren-Lawrence classification on X-ray imaging.