Congenital pseudarthrosis of the tibia: the outcome of a pathology-oriented classification system and treatment protocol.

Abstract

Congenital pseudarthrosis of the tibia is defined as a non-union of a tibial fracture that develops in a dysplastic bone segment of the tibial diaphysis. Pathologically, a fibrous hamartoma surrounds the bone at the congenital pseudarthrosis of the tibia site. The cases of 25 children, who have congenital pseudarthrosis of the tibia, were included in this study. Their ages ranged from 15 months to 15 years at the time of treatment. Neurofibromatosis-1 was present in 24 children. They were managed according to our classification system and treatment protocol. The treatment for mobile pseudarthrosis (types 1 and 2) included complete excision of the pathological periosteum, insertion of autogenous iliac crest bone graft, and combined fixation using intramedullary rod and Ilizarov external fixator. For type 3 pseudarthrosis (stiff pseudarthrosis), a pre-constructed Ilizarov fixator was applied for simultaneous distraction of the pseudarthrosis and deformity correction without open surgery. Evaluation of results was mainly radiological and included achievement of union, leg length equalization, deformity correction and prevention of refracture. Consolidation of the pseudarthrosis and osteotomies was achieved in all cases (100%). Refracture occurred in one case (4%) at the site of previous pseudarthrosis. Residual limb length discrepancy more than 2.5 cm occurred in two cases (8%). Valgus deformity of the ankle was present in 12 cases (48%) and was treated by supramalleolar osteotomy. Follow-up ranged from 24 to 48 months (average 36.9 months) after fixator removal. The results of our treatment protocol, based on our classification system, have been consistently good and predictable in all cases of congenital pseudarthrosis of the tibia. Mobility of the pseudarthrosis is an important factor in choosing the type of interference.