The effects of helium-neon light therapy on healing of partial osteotomy of the tibia in streptozotocin induced diabetic rats.
OBJECTIVE
The effect of light therapy (LT) on surgically created partial osteotomy in streptozotocin (STZ)-induced diabetic rats was examined.


BACKGROUND
LT has been shown to enhance bone repair in healthy human and animal models.


METHODS
Forty male rats were divided into groups 1 to 5. Diabetes was induced in rats of groups 1, 2, and 3 using an intraperitoneal injection of STZ. All diabetic rats were maintained for 30 days after STZ injection. Under general anesthesia and sterile conditions, a partial transversal standardized osteotomy was made in the mid-portion of the right tibia. The defects in groups 2, 3, and 5 were treated using a helium-neon (He-Ne) laser (632.8 nm, 10 mW, circular beam shape). Groups 1 and 4 were diabetic placebo and normal placebo groups, respectively. A dose of 369.4 J/cm2 for groups 2 and 5 and a dose of 66.8 J/cm2 for group 3 were applied three times a week. Six weeks after surgery, the right tibia was collected. The specimen was subjected to a three-point bending test.


RESULTS
LT with 369.4 J/cm2 energy density resulted in significantly greater bending stiffness in group 5 (41.8+/-5.2) than in groups 1 (18.5+/-4.1), 2 (17.7+/-1.6), and 3 (11.5+/-4) (least significant difference (LSD) test, p<0.01, p<0.001, and p<0.001, respectively). LT with 369.4 J/cm2 energy density resulted in a significantly higher stress load in group 5 (10+/-0.4) than in groups 1 (4.9+/-1.5), 2 (5.7+/-0.52), and 3 (3.9+/-1.1) (LSD test, p<0.01, p<0.01, p<0.001, respectively).


CONCLUSIONS
LT with a He-Ne laser in STZ-induced diabetic rats did not enhance bone repair of a partial transversal standardized osteotomy.
Abdi
Shabnam
S
Medical Faculty, Cellular and Molecular Biology Research Center, Department of Pathology, Ayatollah Taleghani Hospital, Shahid Beheshti University, M.C., Tehran, Iran.
Bayat
Mohammad
M
Javadieh
Farshad
F
Mohsenifar
Zhaleh
Z
Rezaie
Fatemesadat
F
Bayat
Maryam
M
D000704:Analysis of Variance; D000818:Animals; D003921:Diabetes Mellitus, Experimental; D004195:Disease Models, Animal; D017102:Fracture Healing / Q000528:radiation effects*; D006371:Helium; D028022:Low-Level Light Therapy / Q000379:methods*; D008297:Male; D009356:Neon; D010027:Osteotomy; D051381:Rats; D017208:Rats, Wistar; D018709:Statistics, Nonparametric; D013311:Streptozocin; D013314:Stress, Mechanical; D013977:Tibia / Q000293:injuries* / Q000601:surgery; D013978:Tibial Fractures / Q000532:radiotherapy*
D006371:Helium; D009356:Neon; D013311:Streptozocin