Congenital pseudarthrosis of the tibia
[3] 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.
[1][8] Secondary CPT does not present with obvious bowing at birth and may be overlooked, but will eventually progress to pathological fracture as the infant grows.
[21] Additionally, overexpression of the Ras pathway can increase the activity of osteoclasts and their precursors, contributing to bone resorption in CPT and the high incidence of recurrent fractures.
[22][23] In this case, the underlying pathogenic mechanisms of CPT likely involve a combination of signal abnormalities that enhance osteoclast activity, along with disturbances in osteoblastic differentiation, ultimately leading to defective bone remodeling.
Orthopaedic surgeons then stabilize and compress the resultant bone fragments securely using internal fixation devices like plates, screws or intramedullary rods.
By intentionally fracturing the bone in a regulated manner and ensuring stability, Sofield fragmentation promotes healing while also assisting consolidation at the pseudarthrosis site.
Surgeons may opt for flexible or rigid intramedullary nails depending on patient-specific factors such as age, pseudarthrosis severity and any accompanying deformities.
[28] Although it almost guaranteed fracture healing and no refractures within a few years, the intramedullary nails would need to be replaced with age, leading to the pain of repeated surgery.
[29][30][31] In cases of extensive tibial bone loss or compromised blood flow, surgeons may perform a free vascularized fibular graft.
This involves harvesting a section of fibula (usually 10–12 cm long) along with its blood supply from the patient's leg and transplanting it to the pseudarthrosis site.
[32] As a vascularized graft, the fibula provides a fresh blood source to aid bone growth and repair at the defect location.
[34] However, due to the lack of mechanical support, the healed bone has a high chance of refracture if this technique was applied alone for CPT treatment.
[35] Therefore, it is commonly applied together with intramedullary nails in recent years so as to deal with both tibial loss and low bone mechanical strength, and has demonstrated satisfying efficacy in clinical practice.
[39] Site and type of pseudarthrosis have an impact on treatment success rate, as a lower location of fracture increases the complexity of the surgical operation due to the proximity with the ankle joint.
[40] Patients with a history of multiple surgical interventions and recurrent fractures also indicate poor prognosis, and suggest a high risk of refracture after treatment.
