The Impact of Photobiomodulation Therapy on Swelling Reduction and Recovery Enhancement in Total Knee Arthroplasty: A Randomized Clinical Trial

<b><i>Background:</i></b> Total knee arthroplasty (TKA) is commonly performed for severe osteoarthritis but often results in significant postoperative swelling and discomfort, impacting early rehabilitation. Photobiomodulation therapy (PBMT), utilizing low-level laser therapy (LLLT), has emerged as a potential adjunctive treatment to alleviate these symptoms. <b><i>Methods:</i></b> In this single-center, nonblinded prospective randomized clinical trial, conducted from May to July 2024, 30 patients undergoing primary TKA were enrolled and divided into two groups. Fifteen patients formed the control group receiving standard postoperative care, while the intervention group consisted of another 15 patients who received additional PBMT from the first to the fifth postoperative day (POD). The swelling was assessed using bioimpedance analysis, which offers a noninvasive, safe, and efficient method for assessing postoperative swelling by measuring tissue impedance, and functional outcomes were measured using the 2-min walk test (2MWT) and active range of motion (aROM). The study was registered with ClinicalTrials.gov (NCT06426251). <b><i>Results:</i></b> The PBMT group demonstrated significantly lower impedance, reactance, and phase angle ratios by POD6, suggesting reduced swelling compared to the control group. In the 2MWT, the PBMT group achieved a longer walking distance of 27 m, compared to 16 m in the control group. However, there were no significant differences in aROM or Visual Analogue Scale (VAS) pain scores between the groups. <b><i>Conclusions:</i></b> The findings indicate that PBMT effectively reduces postoperative swelling and enhances early mobility post-TKA. These benefits suggest that PBMT can be a valuable addition to conventional postoperative care, potentially accelerating functional recovery, and reducing rehabilitation time.