Pseudoarthrosis is seen in all of the following except-
Congenital Pseudarthrosis

Pseudarthrosis, as the name suggests, is false joint, i.e. there is abnormal mobility between the two fragments of a bone.
Pseudarthrosis may be :


Acquired :- When a fractured bone fails to unite, i.e. in nonunion (has been explained in earlier chapters).
Congenital :- There is dysplasia of bone and soft tissue of a limb with failure of normal bone formation. Congenital Pseudarthrosis may be :-


Idiopathic  
Neurofibromatosis type I (most common cause)          
Fibrous dysplasia   
Amniotic constriction band
Osteogenesis imperfecta
Cleidocranial dysplasia
AS (infused bumboo spine)
Idiopathic
Fracture
Osteomyelitis
Neurofibromatosis