[Correlative study between X-ray type after healing of congenital pseudarthrosis of the tibia in children and postoperative refracture].

Objective: To investigate the relationship between postoperative X-ray type in 2 years after healing of congenital pseudarthrosis of the tibia(CPT) and refracture of CPT in children. Methods: A retrospective study was performed on 67 children patients with Crawford type Ⅳ CPT who were treated with combined surgeries from December 2007 to August 2012.There were 46 male and 21 female patients with 37 cases with left CPT and 30 cases with right CPT. There were 12 cases with proximal tibia dysplasia, 56 cases with neurofibromatosis type 1. The median age when operation was 2.8 years(from 0.6 to 11.2 years). The patients were divided into three groups, CPT with hypertrophic group, CPT with mediate group and CPT with atrophic group, on the basis of ratio of healing cross-sectional area and transition zone in pseudarthrosis.The incidence of refracture in the three groups were investigated. Results: The refracture rates of three groups were 13%(5/38), 14%(3/21), 5/8, respectively.The refracture rate difference between CPT with hypertrophic group and CPT with mediate group was not statistically significant(P=0.590). The refracture rate of CPT with atrophic group was statistically significant lower than that of CPT with hypertrophic group and CPT with mediate group(P=0.007, 0.019). In addition, the refracture-free cumulative survival rate of CPT with hypertrophic group or CPT with mediate group was higher than that of CPT with atrophic group with the statistically significant difference(both P<0.05). And the refracture-free cumulative survival rate in CPT with hypertrophic group was lower than that in CPT with mediate group, the difference was not significant(P>0.05). Conclusion: After the union of CPT, patients with hypertrophic, mediate type X ray characteristic showed lower incidence of refracture than those with atrophic type.