Effect of He-Ne laser verus low-level CO2 laser irradiation on accelerating fracture healing

Jian TENG; Yaping LIU; You ZHANG; Ziliang ZHOU; Jianhua GENG

ABSTRACT

BACKGROUND:

The effects of low-level laser biostimulation have been proved by various experimental studies and clinical application, which are manifested as tissue repairing, analgesia, antiinflammation, etc.

OBJECTIVE:

To observe the effects of He-Ne laser and low-level CO2 laser irradiation on fracture healing.

DESIGN:

A randomized controlled animal experiment.

SETTING:

Research Room of Laser Medicine, Chengde Medical College.MATERIALS Forty-eight healthy male New Zealand rabbits, weighing 2.0-2.5 kg, were used.

METHODS:

The experiments were carried out in the Research Room of Laser Medicine, Chengde Medical College from 1998 to 2003. ①The 48 rabbits were induced into models of experimental fracture of the left radius, and then they were divided into three groups with 16 rabbits in each group control group, He-Ne laser irradiation group and CO2 laser irradiation group. The fracture areas of the animals in the He-Ne and CO2 laser irradiation groups were respectively irradiated with 28 mW/cm2 He-Ne laser and 150 mW/cm2 CO2 laser for 10 minutes, once a day. ② The animals were killed on the 15th and 35th days after taking roentgenogram respectively. At 15 days, the collagen and calcium contents in callus were detected. At 35 days, the biomechanic anti-torsion strength was examined.MAIN OUTCOME

MEASURES:

①Results of roentgenogram in each group; ② Collagen and calcium contents in callus; ③ Results of biomechanic anti-torsion strength.

RESULTS:

Totally 45 rabbits were involved in the analysis of results. ① On the 15th and day after fracture, the roentgenogram, collagen and calcium contents in callus in the He-Ne and CO2 laser irradiation groups were better than those in the control group, and the collagen and calcium contents in callus were higher in the CO2 laser irradiation group than in the He-Ne laser irradiation group [(341.9±30.1) vs (302.1±28.7) mg/g; (197.1±19.7)vs (156.5±17.6) mg/g, P＜ 0.05]. ②On the 35th days after fracture, the biomechanic anti-torsion functions in the He-Ne and CO2 laser irradiation groups were superior to that in the control group, and there were no significant difference between the two laser irradiation groups. ③ The results of roentgenogram in the He-Ne and CO2 laser irradiation groups were better than that in the control group both on the 15th and 35th days after fracture, and there was no significant difference between the two irradiation groups.

CONCLUSION:

Both CO2 laser and He-Ne laser irradiations can accelerate the process of fracture healing, and the curative effect of CO2 laser is better than that of He-Ne laser on the 15th day after fracture, but there is no significant difference clinically between the CO2 laser and the He-Ne laser irradiations on the 35th day after fracture.