Effect of Low-Level Infrared Laser Therapy on Large Surgical Osteochondral Defect in Rabbit: A Histological Study

Abstract

Objective: The present study investigates whether low-level laser therapy (LLLT) can accelerate healing of large osteochondral defects in rabbits. Background Data: LLLT has been used in the treatment of musculoskeletal disorders and fractures. Materials and Methods: Seventy rabbits were divided into control and experimental groups. Under sterile conditions and after general anesthesia, the rabbits received one full-thickness defect 5 mm wide by 10 mm deep in the distal portion of the patellar groove of the right femur. The rabbits in the experimental group were exposed to a pulsed 890-nm infrared laser (1500 Hz, 4.8 J/cm² energy density, spot size 1 cm) twice weekly. The rabbits were killed at 2 wk, 1 mo, 2 mo, and 4 mo post-surgery. The defects were evaluated macroscopically and histologically for the filling of the defect, integration of repair tissue, matrix staining, and cellular morphology. The Student's t-test was performed to determine the differences between the control and experimental groups. Statistical significance was set at p ± 0.05. Results: Results in the experimental group were better than those in the control group; however, there were no significant differences between the two study groups. Conclusion: LLLT did not accelerate healing of large osteochondral defects in rabbits.