What Causes Hip Dysplasia/ DDH?
The exact cause of DDH is unknown, but research has discovered several theories and risk factors for hip dysplasia. In the general population, the overall incidence of DDH is approximately 3-4 per 1,000 live births. There is often a genetic component, or familial tendency. Anything that causes cramping or crowding of the fetus inside the uterus (large birth weight, oligohydramnios: decreased amniotic fluid) is thought to cause an increased incidence of DDH. More significant risk factors for DDH include female gender, first born babies, and babies born in the breech position (especially with feet up by the shoulders). Hip dysplasia is approximately 5-9 times more common in females than males. In addition, DDH affects the left hip more often than the right hip (approximately 60% affect only left hip, 20% only right hip, and 20% are bilateral.) Finally, there is felt to be a slightly higher incidence of DDH when other orthopaedic (torticollis, metatarsus adductus, clubfoot) or connective
