Congenital Pseudarthrosis of the Tibia: A Comprehensive Literature Review.

Abstract

» NF1 Link and Pathophysiology: Congenital pseudarthrosis of the tibia (CPT) is strongly associated with neurofibromatosis type 1 (NF1), where loss of normal NF1 gene function impairs bone formation and promotes fibrous hamartoma, resulting in recurrent tibial nonunion.» Classifications and Diagnostics: Multiple radiographic classifications (Andersen, Crawford, Boyd, Paley, etc.) guide clinical decision making, while newer imaging (magnetic resonance imaging, quantitative ultrasound) refines diagnosis and helps tailor interventions.» Treatment Modalities: Strategies range from nonoperative bracing (prefracture) to surgical approaches such as intramedullary rods (standard or telescopic), free vascularized fibular grafts, ring fixators (Ilizarov), and "cross-union" procedures-often combined with pharmacologic agents such as bone morphogenetic proteins (BMPs) or bisphosphonates.» Mixed Results With Pharmacologics: While rhBMP and bisphosphonates address bone catabolism and anabolism, neither agent alone has consistently succeeded in NF1-related CPT; combination regimens may offer better outcomes but require more robust research.» Future Directions: Ongoing studies explore early surgery (vs. waiting until age 2-3) and guided growth to address tibial bowing, molecular therapies (e.g., MAPK kinase and Src homology 2 containing protein tyrosine phosphatase 2 inhibitors), and refined fixation techniques. The management of CPT continues to evolve as genetic and cellular mechanisms become clearer.