The relationship between developmental dysplasia of the hip and congenital muscular torticollis.

Multiple studies report a correlation between congenital muscular torticollis (CMT) and developmental dysplasia of the hip (DDH) at a rate between 2% and 29%. Most of these studies were completed before the routine use of hip ultrasound. This study assesses the incidence of DDH in a referral population with CMT and the incidence of CMT in a referral population with DDH.