Evaluation of low-level laser therapy with a He-Ne laser on the healing of an osteochondral defect using a biomechanical test.

摘要

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.