Total knee replacement (TDP) surgery is recognized as an effective surgical option for patients who develop moderate to severe osteoarthritis of the knee. Before, during and after TDP surgery, patients experience physical, psychological and social problems. After TDP surgery, patients may experience problems such as dependency and sleep problems in their daily living activities. Patients who have sleep problems, who cannot rest enough, become tired and experience anxiety as a result. It has been stated that the education given to the patients in the preoperative period reduces anxiety and analgesic needs and increases satisfaction. Progressive relaxation exercises in patients It has been shown to be effective in reducing symptoms such as anxiety, pain and fatigue. With the widespread use of mobile technologies, a rapid development is observed in mobile health applications and it is thought that its use in the field of health will provide great benefits to nursing services. This study is of the randomized controlled experimental type. During the application process, a mobile-based training and exercise program will be applied to the patients in the experimental group. As the education content, information about pre- and post-operative information and video-supported training content that will guide the patients with voice commands about the exercises that the patients will do before the surgery will be included in the mobile application. With the implementation of this program, continuity will be ensured by meeting the information needs of the patients before and after the surgery, and by performing progressive relaxation and knee exercises correctly and regularly. With the use of this mobile application, it is aimed to increase the physical functions of the patients by reducing the level of anxiety and fear of movement.

Inclusion Criteria:

• Patients who were decided to undergo total knee replacement surgery with the diagnosis of osteoarthritis,
• Patients who will undergo elective surgery
• Patients who will undergo unilateral total knee replacement surgery for the first time
• Patients who can be communicated verbally
• Patients without any psychiatric disease
• Patients who use smartphones and agree to participate in the study

Exclusion Criteria:

• Patients under the age of 18
• Patients who have had previous total knee replacement surgery
• Patients who underwent total knee replacement with emergency surgery
• Patients who will undergo bilateral total knee replacement surgery
• Patients with a previous psychiatric diagnosis
• Patients with verbal communication disorders