Congenital pseudoarthrosis of the tibia
Congenital tibial pseudoarthrosis of the tibia describes abnormal bowing that can progress to a segment of bone loss simulating the appearance of a joint. The condition is usually apparent shortly after birth and is rarely diagnosed after the age of two.
The aetiology is unclear, however, around 50% of cases are associated with neurofibromatosis type 1 (NF1). Overall, 10% of patients with NF1 are diagnosed with tibial pseudoarthrosis.
Congenital ulnar pseudarthrosis and radial pseudoarthrosis can also occur, but much less frequently, and usually only in patients with NF1.
- progressive bowing (usually anterolateral in the tibia)
- resorption of a short segment of bone
- usually at the site of maximal bowing
- usually between mid and distal one-third of the shaft
- angulation at the site of absent bone segment
- often mimics the appearance of a joint
- cupping of the bone proximal to the absent section
- sharpened narrow appearance of the distal bone
- often fracture or bowing of accompanying bone (fibula with tibia, radius with ulna)
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- 2. Ramelli GP, Slongo T, TschäPpeler H et-al. Congenital pseudarthrosis of the ulna and radius in two cases of neurofibromatosis type 1. Pediatr. Surg. Int. 2001;17 (2-3): 239-41. Pubmed citation
- 3. Berber R, Berber O, Taguri N et-al. Pseudarthrosis of the tibia: emergency department presentation of neurofibromatosis type 1 in a 4-month-old infant. Emerg Med J. 2009;26 (4): 306-7. Emerg Med J (full text) - doi:10.1136/emj.2008.064105 - Pubmed citation