抗感染重组合异种骨治疗感染性骨缺损的实验研究

目的研究抗感染重组合异种骨（anti-infective reconstituted bone xenograft,ARBX）对感染性骨缺损的治疗作用。方法于2011年1月至2011年10月,32只新西兰种成年兔随机分为四组,每组8只,每只兔子胫骨近端做成大小为1.0cm×2.0cm×1.0cm的矩形骨缺损模型,注入金葡球菌,2周后再次手术行病灶情除,分别在骨缺损中植入ARBX（ARBX组）、植入重组合异种骨（reconstituted bone xenograft,RBX）并肌注庆大霉索（RBX＋全身用药组）,单纯植入RBX（RBX组）以及不植骨（不植骨组）。术后8周对缺损修复情况行大体解剖学、放射学、组织学、细菌学检查。结果①ARBX组细菌计数及改良X线Norden感染分值极低,明显小于其他各组（P〈0.01）,其解剖学和组织学观察均无明显的骨髓炎表现;②RBX＋全身用药组与RBX组的细菌计数,改良X线Norden感染分值均较高,明显大于ARBX组及不植骨组（P〈0.01）;其解剖学和组织学均显示出严重的感染表现。结论①在病灶清除后,ARBX一期植入能有效治疗感染性骨缺损;②在全身用药或不用药条件下,一期植入RBX反而会加重感染。

Therapeutic Effect of Anti-infective Reconstituted Bone Xenograft on Infective Bone Defect in Proximal Tibia of Rabbits

Objective To investigate the therapeutic effect of anti-infective reconstituted bone xenograft（ARBX） on infective bone defect. Methods From January 2011 to October 2011, 32 adult New Zealand rabbits were randomly divided into four groups （group A, B, C, D） with 8 rabbits in every group. The full-thickness defects of bone model, 1 cm × 2.0 cm ×1.5 cm in size, were made in the right proximal tibia for each rabbit, which was injected with staphylococcus. Two weeks postoperatively, the animals underwent clearance of the focal lesion, followed by implantation of ARBX containing gentamicin in group A, reconstituted bone xenograft（RBX） in conjunction with intramuscular gentamicin for 5 days in group B, RBX without antibiotic in group C, and those in group D were left without bone grafting. The healing of the defects was observed by gross, radiology, histological and bacteriological examinations 8 weeks after the above procedure. Results 1） In group A the bacteria counting and modified Norden scoring were by far the smallest among all 4 groups （P 0.01）, with no histological and gross manifestations of infection; 2） The bacteria counting, modified Norden scoring as well as the histological and gross manifestation in gloup B, C were at the same levels and were less than those in group D （P 0.01）. Conclusion 1） ARBX could be implanted as primary graft into the remaining infected defect after debridement to effectively treat chronic infective bone defect; 2） Conventional systemic administration of antibiotics following debridement was not effective in primary bone grafting treating infective bone defect; 3） Primary bone grafting would rather make the condition worse when conventional systemic administration of antibiotics or not any antibiotic was being used.