低强度脉冲超声对兔腰椎融合区软骨内成骨的影响

目的:观察低强度脉冲超声对兔腰椎融合区软骨内成骨的影响,探讨其可能的作用机制.方法:20只新西兰兔行双侧腰椎后外侧融合术,左侧植入自体髂骨,右侧植入羟基磷灰石人工骨.所有实验兔随机分成治疗组和对照组,治疗组于术后1周开始低强度脉冲超声治疗,共4周;对照组予以假治疗.于手术结束及超声治疗结束时摄腰椎后前位X线片观察融合情况;组织学检测观察融合区形态学结构,并计数软骨细胞.结果:治疗组X线融合率明显高于对照组(P＜0.05).组织学切片发现治疗组融合区骨小梁结构丰富,软骨细胞数量明显高于对照组(P＜0.05),髂骨组与人工骨组治疗后软骨细胞数量无统计学差异(P＞0.05).结论:低强度脉冲超声能提高兔腰椎后外侧融合的植骨融合率,其可能机制是促进软骨内成骨.

Effect of low-intensity pulsed ultrasound on the enchondral bone formation in posterolateral lumbar fusion in rabbits

Objective To observe the effect of daily low-intensity pulsed ultrasound (LIPUs) therapy on improving the enchondral bone formation in lumbar fusion in rabbit models, and to explore its possible mechanism.Methods Posterolateral noninstrumented bilateral fusions were performed at the L5~L6 levels in 20 New Zealand rabbits. The autograft iliac bone was implanted on the left side, and the hydroxyapatite bioceramic artificial bone on the right. The rabbits were divided into a treatment group and a control group randomly. One week after the surgery, LIUPs was administered for 20 minutes per day for 4 weeks over the fusion site in the treatment group and false treatment was used in the control group. Post-anterior X-ray photographs were taken to determine the conditions of fusion area, and then, rabbits were killed and the fusion tissues were obtained. Chondrocytes were detected by histological and cytological Methods .Results Compared with the control group, the fusion rate of the treatment group was significantly up-regulated (P<0.05). There was plenty bone trabecula in the fusion area in the treatment group, the number of chondrocytes was also higher than that of the control group (P<0.05), and there was no statistical difference in the number of chondrocytes between the iliac and artificial bone tissues after the treament(P>0.05).Conclusion Low-intensity pulsed ultrasound therapy improves the endochondral bone formation in the lumbar spine fusion in rabbit models.