Congenital Pseudarthrosis of the Tibia [CPT]

Congenital Pseudarthrosis of the tibia is a developmental condition affecting the tibia or tibia and fibula.



CPT is due to hamartomatous tissue surrounding the tibia, which results in anterior or anterolateral bowing, fracture, and pseudarthrosis.



The fracture can occur at birth, or also secondarily, and fails to heal because of impaired callus formation, resulting in a pseudarthrosis.



Since the pseudarthrosis usually occurs secondarily, the term congenital tibial dysplasia is preferred now.

The exact cause is still unknown; however, there are numerous theories have been proposed.



Various theories include vascular insufficiency, genetic defect, nutritional deficiency, fetal damage or compression by the amniotic band, disturbance of neural tissue and function, endocrine imbalance, embryonic defect in neuro-vascular supply, and infection during pregnancy.



Pathologic periosteum is the may reason for the disease with marked thickening of periosteal tissue, which constricts the bone and causes atrophy and pseudarthrosis.



CPT is associated with neurofibromatosis (50%), fibrous dysplasia(10%), and idiopathic(40%) cases.

Usually, anterolateral deformity of leg noticed at birth. The apex of the deformity is pointed towards the lateral side of the leg and foot is inverted or medially displaced in relation to the lower leg.



There will be a shortening of the leg due to bowing and a decrease in distal tibial growth.



When the fracture is present, abnormal painless motion is present i.e. pseudarthrosis.



We have to look for the cutaneous marker of neurofibromatosis.

Diagnosis can be made from plain radiographs, anteroposterior and lateral views of the leg.



MRI provides excellent details of the extent of the pathological process.

Pre-fracture treatment includes casting in very young children and brace application in older children.



Post fracture treatment aim is to obtain union, prevent re-fracture, to equalize the limb length, and to prevent or correct deformities of leg and ankle.



Principles of treatment are excision of pseudarthrosis with pathogenic periosteum, intramedullary stabilization {proper mechanical alignment, prevent recurrence of deformity, and decrease the incidence of re-fracture}, autologous cortical bone grafting, extramedullary stabilization with the orthosis and biological modulation.

The natural history of CPT is extremely unfavorable.



Once a fracture occurs, there is little or no tendency for the lesion to heal spontaneously.



CPT is difficult to treat also with a substantial risk of non-union, re-fracture, leg length discrepancy, and malalignment of tibia and ankle.