Evaluation of Low-Level Laser Therapy with a He-Ne Laser on the Healing of an Osteochondral Defect Using a Biomechanical Test

Objective: The aim of the present study was to examine the influence of low-level laser therapy (LLLT) on the healing of an osteochondral defect in rabbits. Background data: Full-thickness defects of articular cartilage in the knee have a negligible capacity to heal spontaneously. Biostimulatory effects of LLLT on chondrocytes and articular cartilage were reported. Materials and Methods: An osteochondral defect with a 5-mm diameter was surgically induced in the right femoral patellar groove of forty-two adult male rabbits. They were divided into control and experimental groups. The experimental group received He-Ne laser treatment (632.8 nm, 10 mW, circular laser beam, with a surface area of 0.0314 cm(2)) of 148.4 J/cm(2) three times a week. The control group received placebo LLLT with the equipment switched off. Each group was divided into four subgroups: A, B, C, and D. The subgroups were sacrificed at 2, 4, 8, and 16 wk after surgery, respectively. The femur was removed and the defect was examined biomechanically by the in-situ indentation method. The instantaneous stiffness, maximum force, equilibrium load, and energy absorption were calculated. Results: The results of the experimental group were higher than those of the control group. Only one significant difference was observed between the control and experimental groups: the second part of the energy absorption of the experimental group (56.11 +/- 11.5) was significantly higher than that of the control group (18.9 +/- 4) (p = 0.015) 4 wk after surgery. Conclusion: LLLT with a He-Ne laser of an osteochondral defect in rabbits could not significantly accelerate the healing of the osteochondral defect from a biomechanical standpoint when compared with a control group.