骨应力刺激仪叩击治疗促进兔胫骨缺损内成骨及支架降解的实验研究

Bone stress stimulation to promote bone formation and scaffold degradation in rabbit tibial defects

目的探讨骨应力刺激仪叩击治疗能否加速兔胫骨缺损内新骨生成及脱蛋白松质骨（DPB）支架的降解。方法取30只新西兰大白兔，均在右胫骨中段制备长5mm的骨缺损模型，骨缺损两端用钢板固定，随机分为3组：A组（n=12）在骨缺损处植入DPB并给予骨应力刺激仪叩击治疗；B组（n=12）植入DPB不给予应力刺激；C组（n=6）为空白对照组验证骨缺损模型是否成功。所有动物术后均给予下肢免负重石膏固定制动以限制活动。术后第2、4、8、12周行X线片检查并用Lane—Sandhu骨愈合评分标准评估骨缺损愈合程度，并于术后第4、12周时取材组织学（n=6）染色并进行定量分析A、B组中成骨量及DBP的降解速度。结果术后第2、4、8、12周A组的X线片Lane—Sandhu骨愈合评分均明显高于B组和C组，差异均有统计学意义（P〈0．05）。术后第12周时可见C组骨缺损未修复，骨缺损造模成功。HE染色结果：术后第4、12周时A组的新生骨量占骨缺损总面积的百分比（25．4％±4．2％、38．6％±6．3％），均显著高于同时间点的B组（7．6％±2．2％、20．4％±4．2％），差异有统计学意义（P〈0．05）；A组的残余支架占骨缺损面积的百分比（15．1％±3．7％、1．3％±0．9％）均显著低于B组（27．5％±2．4％、19．7％±4．2％），差异均有统计学意义（P〈0．05）。结论骨应力刺激仪叩击治疗能加速兔胫骨缺损内新骨生成及DPB支架的降解，有效促进骨缺损再生修复。

Objective To explore if postoperative rapping by a bone stress stimulator can accelerate bone formation and degradation of deproteinization bone （DPB） scaffolds in rabbit tibial defects. Methods A segmental bone defect of 5 mm long was created in the middle of the right tibial shaft in 30 New Zealand rabbits which were randomly divided into 3 groups. The defects were stabilized with a plate and screws. In group A （ n = 12）, the bone defect was filled with a DPB matrix scaffold and stimulated by rapping by a bone stress stimulator. In group B （ n = 12）, the defect was just filled with a DPB scaffold. In group C （ n =6）, the defect was left untreated. The right lower limbs of all the rabbits were fixated with a plaster slab after operation. Lane-Sandhu X-ray evaluation system was used to evaluate the bone healing process by X-ray examinations at 2, 4, 8 and 12 weeks. The osteogenesis and biodegradation speed of the scaffold were evaluated using histological quantitative analysis at 4 and 12 weeks. Results The mean Lane-Sandhu X-ray scores in group A were significantly higher than in groups B and C at all the time points （ P 〈 0. 05）. At 12 weeks, the bone defects in group C were not repaired, showing successful modeling of bone defects. HE staining showed that at 4 and 12 weeks postoperation the rates of new bone formation area in group A （25.4 ± 4.2% and 38.6% ± 6. 3% ） were significantly greater than in group B （7.6% ± 2.2% and 20. 4% ± 4.2% ） （ P 〈 0. 05）, and the rates of residual DPB area in group A （15. 1% ± 3.7% and 1.3% ± 0.9% ） were significantly lower than in group B （27.5% 22.4% and 19.7% 24.2%） （P 〈0.05） . Conclusion Rapping by a bone stress stimulator is effective on promoting callus formation and DPB degradation in the rabbit tibial defects.