combined surgery for enrolled patients with CPT(Congenital Pseudarthrosis of Tibia): sleeve resection of the pathological soft tissues, intramedullary rod fixation, packaged lilac bone autograft,and llizarov external fixation device installation.

llizarov external fixation device was applied to fix the tibia.

Ohnishi criterion: Degree of union was evaluated by the findings on radiographs and classified into three grades( Ohnishi criterion): union, delayed union, and nonunion. Radiographic union was defined as possessing continuity of bone density between the fragments without obvious radiolucent zone between them and possessing cortex-bridging fragments with sufficient thickness and radiodensity on both anteroposterior and lateral radiographs. Delayed union was defined as a process of healing that was slow but was progressing. Nonunion was defined by the healing process that had completely ceased.

Johnston clinical evaluation criterion of Congenital Pseudarthrosis of Tibia (CPT): The outcome was classified as grade

1 when there was unequivocal union with full weight-bearing function and maintenance of alignment requiring no additional surgical treatment; grade 2 when there was equivocal union with useful function, with the limb protected by a brace, and/or valgus or sagittal bowing for which additional surgery was required or anticipated; and grade 3 when there was persistent nonunion or refracture, requiring full-time external support for pain and/or instability.

measurement of the angulation of proximal tibia in anterior and posterior (AP )and lateral X ray