Examining infants' hips--can it do harm?

Attempts to eliminate congenital dislocation of the hip by detecting it early have not been completely successful. It is not known why some infants, checked by competent examiners, still appear late with dislocations. The usual explanations of a mistake by the examiner, or of spontaneous dislocation of a hip that was stable at birth, do not explain why some centres succeed while others fail, or why good examiners may become less effective with experience. The explanation suggested is that the examination itself could be responsible and may actually cause a hip to become unstable.