ABSTRACT
Objective To explore the risk factors related to refracture after union of congenital pseudarthrosis of the tibia with a combined surgical,and to provide an important reference for clinical treatment.Methods From April 2007 to August 2011,40 cases of congenital pseudarthrosis of the tibia (CPT) confirmed by the use of intramedullary nail combined Ilizarov external fixator treatment of bony union were obtained for retrospective analysis.There were 27 males and 13 females,and the average age was 3.6±2.7 years (ranged from 0.8 to 11.3 years),and the follow-up time are all over 36 months.Survival analysis were applied respectively on gender,whether the merger of neurofibromatosis type 1 (NF-1) and ankle joint,operative age,fibular status and the cross-sectional area ratio of healing site.Multifactorial Cox proportional hazards regression analysis was performed on the single factor with statistical significance.Results No significant inter-group differences existed in gender or whether combined NF-1.In operative age ≥3 years group whose refracture-free survival was significantly better than those ＜ 3 years.Intact fibula or stabilised by tibiofibular synotosis or Kirschner wire group showed significantly better refracture-free survival than those with a pseudarthrotic fibula due to neglect or failed synostosis.There was significant difference between ankle joint fixed group and ankle joint unfixed group in mean refracture-free period.With a cross-sectional area median ratio of healing site of 0.15,refracture-free survival was better than those with a lesser value,and the difference was statistical significant.Cox proportional hazards regression analysis showed a negative correlation between the cross-sectional area and the refracture occurred ~=-1.989,P ＜ 0.05),fibular pseudarthrosis and refracture occurred were positively correlated ~=1.506,P ＜ 0.05),operative age and ankle joint status had no relationship with refracture occurred (P ＞ 0.05).Conclusion The major risk factors for refracture after union of congenital tibia pseudarthrosis with the use of intramedullary nail combined Ilizarov external fixator are the smaller cross-sectional area of pseudarthrosis and with fibula pseudarthrosis.