ABSTRACT
Objective To analyze the clinical effectiveness,safety and significance of treatment with external circular fixator,through the relationship of inducible nitric oxide synthase (iNOS) and bone regeneration to further explore the mechanism of the molecular biology of bone lengthening at the same time.Methods Collected bone defect after tibial shaft fractures secondary infection who were treated with external circular fixator as study group (28 cases),all the cases fixed by external circular fixator,20 healthy volunteers as control group.Study group in different time point measured the levels of serum iNOS content,were compared with the control group.Results All patients were scheduled to reach the extremity lengthening and the bone defect were repaired and healed in study group.The bacterial culture results showed that 18 cases (64.29％,18/28) of resistant Staphylococcus aureus,5 cases (17.86％,5/28) of Hemolytic streptocaccus,2 cases (7.14％,2/28) ofP.aeruginosa,one case (3.57％,1/28) of drug-resistant Enterobacter cloacae,one case(3.57％,1/28) of Staphylococcus epidermidis,one case(3.57％,1/28) of Onion-like aeromonas,the proportion of the former two was significantly higher than other bacteria (P ＜ 0.05).The levels of serum iNOS content 1 d after surgery in study group were increased,compared with control group,difference was no significant (P ＞ 0.05).The levels of serum iNOS content 14 d after surgery,stoped extend,1 d stoped extend,3 d stoped extend in study group were significantly higher than those in control group [(118.8 ± 6.6) U/L vs.(86.4 ± 5.4) U/L,(136.2 ± 8.4) U/L vs.(88.2 ± 3.6) U/L,(132.6 ± 9.0) U/L vs.(87.6 ± 4.8) U/L,(103.8 ± 5.4) U/L vs.(86.4 ± 4.2) U/L] (P ＜ 0.05),there was no significant difference between two groups in other times (P ＞ 0.05).Conclusions External circular fixator for the repair and reconstruction effects in patients with bone defect can achieve the desired therapeutic goal,the higher expression of iNOS may be one of the molecular biological mechanisms of bone lengthening.