Bowing or thinning of the tibia

Bowing or thinning of the tibia, or shin bone, occurs in about five percent of people with NF1. Thinning of the tibia is also referred to as pseudarthrosis (SOOD-ar-THROW-sis).

• Is it harmful? Usually, bowing or thinning of the tibia is not harmful, although sometimes it can cause bone fractures. Fractures caused by pseudarthrosis often fail to heal correctly, requiring surgery or, less frequently, amputation.
  
  
• When does it show up? Bowing or thinning of the tibia usually becomes apparent during the first year of life.