Congenital Radioulnar Synostosis 

• Forearms are usually fused with excessive pronation making things like drinking a cup of water a problem. 
• unilateral disease frequently function well (i.e. they use there other arm
• bilateral-dominant side is osteotomized and placed at 30-45 degrees of pronation,non-dominant side = 10-30 degrees of supination.  Resection of the synostosis should not be performed as recurrence in common.