Total knee arthroplasty (TKA) is commonly performed to improve mobility and quality of life in patients with degenerative joint diseases. However, severe postoperative pain, limited mobilization, and fluctuations in vital signs negatively affect recovery, particularly within the first 72 hours after surgery.

Reiki is a non-invasive complementary therapy aimed at enhancing the body's self-healing capacity through energy transfer. This randomized controlled trial aims to evaluate the effects of Reiki on postoperative pain, mobilization, and vital signs in patients undergoing total knee arthroplasty.

Participants will be randomly assigned to either a Reiki intervention group or a control group receiving routine postoperative care. Outcomes will be assessed using validated pain and mobility scales and objective vital sign measurements at the 24th, 48th, and 72nd postoperative hours.

Total knee arthroplasty (TKA) is a widely performed surgical procedure for the management of advanced osteoarthritis and other degenerative joint diseases. Although TKA aims to improve functional mobility and quality of life, patients frequently experience severe postoperative pain, restricted movement, and physiological stress responses, particularly within the first 72 hours following surgery. Inadequate pain control during this early postoperative period may delay mobilization, prolong hospital stay, increase opioid consumption, and negatively affect overall recovery outcomes.

Complementary and integrative therapies have increasingly been incorporated into nursing care to support postoperative recovery. Reiki is a non-invasive, energy-based complementary therapy developed by Dr. Mikao Usui in Japan. It is based on the concept of facilitating the body's self-healing capacity through gentle touch or hands positioned slightly above the body to promote relaxation and physiological balance. Previous studies suggest that Reiki may reduce pain intensity, alleviate anxiety, and contribute to stabilization of physiological parameters; however, evidence remains limited and inconsistent, particularly in orthopedic surgical populations. Moreover, no randomized controlled study has comprehensively evaluated the simultaneous effects of Reiki on postoperative pain, mobilization, and vital signs in patients undergoing total knee arthroplasty.

This study is designed as a randomized, single-blind (statistician-blinded), pretest-posttest controlled clinical trial. The study will be conducted in the Orthopedics Department of Sinop Atatürk State Hospital between September 2025 and September 2026. A total of 90 patients undergoing elective total knee arthroplasty will be enrolled. Sample size was determined through power analysis (80% power, 5% significance level, effect size = 0.60). Participants will be randomly assigned to either the Reiki intervention group (n=45) or the control group (n=45) using block randomization to ensure balanced group allocation.

Participants in the intervention group will receive standardized Reiki therapy administered by a certified Reiki practitioner who has completed Level I and Level II Reiki training. Reiki will be applied at the 24th, 48th, and 72nd postoperative hours, at least four hours after administration of routine analgesic medication. Each session will last approximately 30-45 minutes. The application will involve gentle touch or hands positioned approximately 2 cm above the body at seven primary energy centers (crown, forehead, throat, heart, solar plexus, sacral, and root regions) as well as knee and foot areas. Each point will receive approximately 3-5 minutes of focused application.

The control group will receive routine postoperative care according to institutional protocols without Reiki intervention.

Outcome measures will be assessed immediately before each intervention (pretest) and five minutes after completion (posttest) at the 24th, 48th, and 72nd postoperative hours.

The primary outcome is postoperative pain intensity measured using the Visual Analog Scale (VAS). Secondary outcomes include patient mobilization level measured by the Patient Mobility Scale, vital signs (systolic and diastolic blood pressure, heart rate, and oxygen saturation), number of analgesic doses required after intervention, and time to analgesic requirement.

Data will be analyzed using SPSS statistical software. Descriptive statistics, chi-square tests, one-way ANOVA, paired t-tests, and independent samples t-tests will be used as appropriate. Statistical significance will be set at p < 0.05 with a 95% confidence interval.

Ethical approval has been obtained from the Clinical Research Ethics Committee of Ondokuz Mayıs University. Written informed consent will be obtained from all participants prior to enrollment. Patient confidentiality and data protection principles will be strictly maintained.

This study aims to provide high-level evidence regarding the effectiveness of Reiki as a complementary nursing intervention in postoperative care for total knee arthroplasty patients. Findings may contribute to improving pain management strategies, enhancing early mobilization, reducing reliance on opioid analgesics, and promoting patient-centered integrative care approaches in orthopedic surgery settings.

Inclusion Criteria:

• Adults aged 18 years and older
• Undergoing elective (planned) primary total knee arthroplasty
• Not receiving general anesthesia
• Able to communicate effectively and understand the study protocol
• Hospitalized for two days following total knee arthroplasty

Exclusion Criteria:

• Refusal to participate in the study
• Previous total knee arthroplasty or revision knee surgery
• Prior experience with Reiki, Therapeutic Touch, Healing Touch, or other energy-based therapies
• Development of serious postoperative complications (e.g., bleeding, infection)
• Diagnosis of chronic pain syndrome (e.g., fibromyalgia, chronic low back pain)
• Neuropsychiatric disorders such as dementia, Alzheimer's disease, schizophrenia, or major depressive disorder
• Current use of psychotropic medications
• Regular use of opioids or corticosteroids
• Use of patient-controlled analgesia (PCA)
• Major surgery or severe trauma within the past 6 months
• Admission to the intensive care unit postoperatively

Individual participant data (IPD) collected in this study will not be shared. The dataset contains sensitive clinical information and was collected under institutional ethical approval that does not include provisions for public data sharing.

This study is single-blinded. The statistician (outcome assessor) responsible for data analysis will be blinded to group allocation. Participants and care providers will not be blinded due to the nature of the intervention.