抗感染重组合异种骨对兔胫骨近端骨髓炎的预防作用

Preventive effect of anti-infective reconstituted bone xenograft on osteomyelitis in proximal tibia of the rabbit

目的 探索一种能有效预防术后感染 ,降低骨髓炎发生率 ,同时能促进骨损伤快速修复的方法。 方法 在重组合异种骨 (RBX)基础上 ,结合抗生素缓释技术 ,研制抗感染重组合异种骨(ARBX)。并进一步采用兔胫骨近端骨髓炎模型 ,于胫骨近端骨窗内注入金葡菌后即刻 ,分别植入ARBX(ARBX组 )、植入RBX并肌注庆大霉素 (RBX加全身用药组 )、单纯植入RBX(RBX组 )。术后 8周无菌取材 ,通过解剖学、放射学、组织学、细菌学检查 ,比较上述各组方法对骨髓炎的预防作用。结果 术后 8周 ,RBX加全身用药组的细菌计数及改良的Norden分值较RBX组明显减少 (P <0 0 1) ,但较ARBX组明显增多 (P <0 0 1) ,其解剖学及组织学观察的骨髓炎程度也介于RBX组和ARBX组之间。ARBX组的细菌计数及改良的X线Norden骨髓炎分值均极低 ,明显小于其它 2组 (P <0 0 1) ,其解剖学和组织学观察均无骨髓炎表现。 结论 传统的全身抗生素应用 ,有一定的抗感染能力 ,但当Ⅰ期植骨时 ,不能有效地发挥预防骨髓炎的作用。ARBX除有良好的骨传导和骨诱导作用外 ,还有很好的抗生素缓释作用 ,具有非常强的抗感染能力 ,能Ⅰ期植骨修复细菌污染的骨缺损 。

Objective To assess possible beneficial effect in prevenion of osteomyelitis by anti-infective reconstituted bone xenograft (ARBX) in the rabbit. Methods A proximal tibia osteomyelitis rabbit model was used in which staphylococcus aureus was injected through a bony window, followed by immediate implantation of three ARBX pellets containing 30 mg of slowly-delivered gentamicin in group A, three pellets of RBX in conjunction with intramuscular gentamicin (30 mg) for 5 days in group B, three pellets of RBX without antibiotic in group C. Specimens were harvested 8 weeks postoperatively for gross observation, radiological, histological and bacteriological evaluation, comparing the three groups with regard to the beneficial effect of the above procedures in preventing osteomyelitis. Results (1) Bacteria counting, modified Norden scoring, and gross and microscopic evidence for osteomyelitis in group B were less than those in group C (P<0.01). (2) In group A, bacteria culture and counting yielded 0 values at 8 weeks, while radiologically modified Norden scoring for osteomyelitis gave by far the smallest values among all three groups (P<0.01) with no evidence of osteomyelitis found in gross and histological examinations. Conclusions (1)Conventional systemic administration of antibiotics are reasonably effective in prevention of infection, but the anti-infective effect usually is not strong enough to prevent osteomyelitis when used along with primary bone grafting. (2) Apart from its osteoconductive and osteoinductive effects, ARBX is capable of slowly delivering antibiotics, thus being highly anti-infective when administered locally, so it could be used for primary grafting to repair a contaminated bone defect for effective prevention of osteomyelitis.