Total knee arthroplasty is a common and effective surgical procedure for patients with end-stage knee osteoarthritis, and wound pain is still a problem for many of the patients.

Therefore, the purpose of this study was to apply low level laser therapy Measured variables included postoperative pain intensity, patient-controlled analgesia requirements, side effects caused by morphine, knee stiffness and wound pain in the daily activities of patients undergoing total knee arthroplasty. Data were collected between April 2018 and January 2019. Eighty-two knee osteoarthritis patients receiving total knee arthroplasty were recruited from one hospital and randomly, equally assigned to the laser acupuncture or control group. The LA group received the low-level laser therapy with 3 joules at each acupuncture point at Hour 2, Hour 6, Hour 10, Hour 24, Hour 48, and Hour 72 after surgery; whereas the control group received the same manner except for joule.

Inclusion Criteria:

• age 60 years or older
• American Sociological Association (ASA) class I-III
• spinal anesthesia, consent to patient-controlled analgesia (PCA) and peripheral nerve block (PNB)
• return to the ward directly from the anesthesia recovery room.

Exclusion Criteria:

• cutaneous lesions at the application sites
• use of taking immunosuppressive agents
• received intra-articular steroid treatment
• opiate dependence
• sensitive to light
• epilepsy
• clinically significant cardiovascular diseases
• cancer
• systemic lupus erythematosus.