A Clinical Trial to Evaluate the Safety and Effectiveness of OLIZ, a Photobiomodulation Medical Device for Surgical Site Pain Relief in Patients After Total Knee Arthroplasty

Inclusion Criteria: 1. Adults aged ≥19 years and \<80 years at the time of consent 2. Radiographic evidence (X-ray) within 24 weeks prior to total knee arthroplasty (TKA) showing Kellgren-Lawrence (KL) grade 4 in the surgical knee 3. Surgical site pain confirmed as a visual analog scale (VAS) score ≥50.0 4. Willingness to refrain from any treatments not permitted by the study protocol, aside from concomitant medications or therapies allowed during the study period 5. Voluntary participation in the clinical trial with written informed consent provided after being fully informed of the study procedures 6. Willingness and ability to comply with the requirements of the clinical trial protocol Exclusion Criteria: Subjects will be excluded from this clinical trial if they meet any of the following criteria: 1. History of surgery, other than total knee arthroplasty, in the area of the knee joint being evaluated (or scheduled for surgery).\* \*Includes total/partial knee arthroplasty, knee cartilage surgery, knee ligament reconstruction, autologous chondrocyte implantation, knee fracture surgery, knee synovectomy/loose body removal, patellar reconstruction, patellar realignment, bursectomy, synovectomy, etc. 2. History of using steroids or immunosuppressants at the time of screening, meeting one or more of the following: Immunosuppressants (e.g., cyclosporin A or azathioprine) within 6 weeks. Oral steroids or antidepressants within 4 weeks. Intra-articular injection\* into the target knee joint within 12 weeks. \*Includes steroids, hyaluronic acid, polynucleotide, PDRN (polydeoxyribonucleotide), etc. 3. Determined to be unable to wear the device due to one or more of the following: Individuals with photosensitive skin. Individuals taking medications that may cause light sensitivity (refer to the precautions of the medication being taken). Individuals with sensitive skin due to an allergic constitution. Individuals with implanted electronic medical devices. 4. Meeting one or more of the following physical examination or laboratory test results at the time of screening: Fever exceeding 37.8°C. PT (INR) or aPTT ≥ 1.5 x ULN (upper limit of normal). Serum creatinine \> 1.5 x ULN. AST or ALT ≥ 2.0 x ULN. (Only for those with a history of diabetes) Glycosylated hemoglobin (HbA1c) \> 11%. 5. History of one or more of the following medical conditions or diseases confirmed at the time of screening: Secondary osteoarthritis such as rheumatoid arthritis, Paget's disease, or gouty arthritis (however, traumatic osteoarthritis is permitted for enrollment). History of cardiac disease such as myocardial infarction or congestive heart failure. Uncontrolled hypertension (SBP \> 160 mmHg or DBP \> 100 mmHg). History of uncontrolled endocrine abnormalities or diseases (e.g., thyroid disease, parathyroid disease, pituitary disease). Immune system-related diseases (e.g., infectious diseases, systemic lupus erythematosus). History of malignancy within the last 5 years (however, individuals with a history of basal cell or squamous cell skin cancer and non-invasive carcinomas are eligible to participate in the clinical trial only if adequately treated). 6. Pregnant or lactating women. 7. Women of childbearing potential who do not agree to use medically acceptable birth control methods\* during the clinical trial period. \*Hormonal contraception, intrauterine devices, tubal ligation, double barrier methods (combined use of barrier methods such as male condoms, female condoms, cervical caps, diaphragms, contraceptive sponges), or a single barrier method combined with spermicide. 8. Currently participating in another clinical trial or having participated in another clinical trial within 30 days prior to the screening date. 9. Any other case where, in the investigator's judgment, participation in the clinical trial is deemed inappropriate due to ethical reasons or potential impact on the clinical trial results. \-