摘要
Abstract
BACKGROUND: Low power laser irradiation has positive effects on fracture healing, including shortening the time of bone union and enhancement of bone formation. OBJECTIVE: To evaluate the effects of different wave lengths in low power laser on eedy fracture healing. DESIGN, TIME AND SETTING: Randomized, controlled, animal experiment. The study was performed at the Laser Center of Dankook University Medical Center between May 2005 and May 2006. MATERIALS: A total of 60 female English Hartley guinea pigs, 9 weeks old, weighing (300～30) g, were used for this experiment. They were randomly divided into three groups control, 632, and 830 nm groups (n=20). METHODS: The right femoral middle shaft fractures were made with a bone cutter and fixed with intramedullary nails (1.4 mm diameter K-wire). The frequencies of 632 nm and 830 nm semi-conductor laser machines were used. The laser irradiations were started 48 hours after operation vertically at the fracture sites and were applied every two days, at 100 J/cm<'2> of the same irradiation doses and 2.52 cm<'2> of the same irradiation areas in different irradiation groups. Finally, 46 guinea pigs survived, including 14 in control group, 16 in 632 nm group and 16 in 830 nm group. MAIN OUTCOME MEASURES: Guinea pigs were sacdficed at 3 and 6 weeks separately. The bone healing was assessed by the Modified Zorlu Scoring System, including gross, radiologic and histologic examinations. RESULTS: In the gross and radiologic findings, both 632 nm and 830 nm irradiation groups shown a significantly greater rate of callus formation at postoperatively 3 weeks compared to the control group (P< 0.01). Quantity of callus formation in 830 nm group was more than 632 nm group, but there was no significant difference (P > 0.05). The result of histological findings showed a significant increase of osteoblastic proliferation in two irradiation groups than the control group at 3 weeks postoperatively (P < 0.01). Enhancement of osteoblastic proliferation was more obvious in 830 nm group than in 632 nm group at 3 and 6 weeks, but there was no significant difference (P > 0.05).CONCLUSION: Both 632 nm and 830 nm wave lengths are considered to be optimal irradiation wave lengths for eady fracture healing. Moreover, 830 nm irradiation is better than 632 nm irradiation for eady fracture healing.关键词
低能量激光/波长/骨折/豚鼠分类
临床医学
