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.