Relative Factors Of Residual Deformities Following Successful Bone Union In Congenital Pseudoarthrosis Of The Tibia

Objectives:The purpose of this study is to discuss the risk factors for residual deformities after a successful union of congenital pseudarthrosis of the tibia(CPT),the major residual deformities include ankle valgus deformity, limb malalignment and limb length discrepancy.Methods:Eighty-nine patients who had a bone union after combined operations were retrospectively reviewed,the following effects were collected:pseudarthrosis of fibula,NF-1,previous surgical history, gender, side, position,type,age.The relevance between residual deformities and factors were analysed by univariate analysis and binary logistic regression analysis.Results:All of eighty-nine patients were followed up,the average follow-up is 4.17±1.61 years,varying from 2 to 7.58 years.The age of surgical therapy ranging between 0.66 to 12.41 years with a mean of3.52±2.51 years.Among them,fifty-four of these patients had ankle valgus deformity,fifty-one patients had limb malalignment,twenty-eight patients had limb length discrepancy.Univariate analysis showed that there was a high incidence rate of ankle valgus deformity left in group of CPT complicatedwith fibula pseudarthrosis or in group of pseudarthrosis occurred at the junction of distal third of the tibia,and the difference was statistically significant(P<0.05).And there was a high incidence rate of limb length discrepancy after bone union in group of the patient who were older than three years,and the difference was statistically significant(P<0.05).Binary logistic regression analysis showed that CPT complicated with fibula pseudarthrosis and pseudarthrosis occurred at the junction of distal third of the tibia were the independent risk factors for ankle valgus deformity(P<0.05).The patient were more likely remained limb length discrepancy after healing CPT who were older than three years(P<0.05).Conclusions:The fibula pseudarthrosis and pseudarthrosis occurred at the junction of distal third of the tibia were the risk factors for ankle valgus deformity.The patient who were older than three years was the risk factor for limb length discrepancy after healing CPT.