congenital pseudoarthrosis of the tibia

Congenital pseudarthrosis of the tibia

Congenital pseudarthrosis of the tibia (CPT) is a rare paediatric disease presenting with a bowing deformity of the tibia at birth or within the first decade of life. It is most commonly associated with Neurofibromatosis type 1 (NF-1). For children with CPT, pathological fracture of the tibia eventually occurs, resulting in persistent nonunion of the fracture site. If left untreated, leg deformities, joint stiffness, leg-length discrepancy and pain will persist. Diagnosis is done clinically and through X-ray imaging, with numerous classifications based on the severity of bowing and presence of fracture or intraosseous lesion. Pathogenesis of CPT remains unclear. Genetic factors may be related due to its association with NF-1, but does not completely explain the development and location of CPT. It is likely related to the involvement of pathological periosteum in the tibia, resulting in abnormal bone turnover. Treatment for CPT is through surgical correction, to limit the progression of deformity and to correct shortening of the affected limb. Prognosis of treatment depends on site and type of CPT, and there is a risk of recurrent fracture. About 1 in 150,000 births present with CPT, but aside from its association with NF-1, not much else is shown from epidemiological studies.