This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Pediatric Ohopedics, Subject name: Orthopaedics
Cause of congenital pseudoahrosis is: 
Select and explain. 
A. Intrauterine fracture, B. Neurofibromatosis, C. Fibrous dysplasia, D. Unknown
D: Unknown
Answer: D: Unknown 
Explanation: Neurofibromatosis is an association it is not a cause Most Common Cause of Pseudoahrosis - Idiopathic> Neurofibromatosis (NF-1) - (Actually an association, not a cause) Extra edge Musculoskeletal abnormalities in neurofibromatosis Pseudoahrosis oftibia Sho stature Scoliosis (Most common) Limb hyperophy due to multiple neurofibromas Distinctive osseous lesion: sphenoid dysplasia or coical thinning of long bones.