It is also thought that the higher rates in some ethnic groups (such as some Native American groups) is due to the practice of swaddling of infants, which is known to be a potential risk factor for developing dysplasia. It also has a low risk in African Americans and southern Chinese. Congenital
Some studies suggest a hormonal link. Specifically, the hormone relaxin has been indicated.A genetic factor is indicated since the trait runs in families and there is an increased occurrence in some ethnic populations (e.g., Native Americans, Lapps / Sami people). A locus has been described on chromosome 13. Beukes familial dysplasia, on the other hand, was found to map to an 11-cM region on chromosome 4q35, with nonpenetrant carriers not affected. Acquired
As an acquired condition it has often been linked to traditions of swaddling infants, use of overly restrictive baby seats, carriers and other methods of transporting babies, or use of a cradle board which locks the hip joint in an "adducted" position (pulling the knees together tends to pull the heads of the femur bone out of the sockets or acetabulae) for extended periods. Modern swaddling techniques, such as the hip healthy swaddle have been developed to relieve stress on hip joints caused by traditional swaddling methods.Further risk factors include breech birth, gender, genetics (family history), and firstborns. In breech position the femoral head tends to get pushed out of the socket. A narrow uterus also facilitates hip joint dislocation during fetal development and birth.
Cases of femoral nerve palsy and avascular necrosis of the femoral head have been reported with the use of the Pavlik harness, but whether these cases were due to improper application of the device or a complication encountered in the course of the disorder remains unresolved. Complications arise mainly because the sheet of the iliopsoas muscle pushes the circumflex artery against the neck of the femur and decreases blood flow to the femoral head, so the Frejka pillow is not indicated in all the forms of the developmental dysplasia of the hip. Other devices employed include the spica cast, particularly following surgical closed reduction, open reduction, or osteotomy in babies and young children. Traction is sometimes used in the weeks leading up to a surgery to help stretch ligaments in the hip joint, although its use is controversial and varies amongst physicians. Surgery
In older children  the adductor and iliopsoas muscles may have to be treated surgically because they adapt to the dislocated joint position (contracture). Braces and splints are often used following either of these methods to continue treatment. Although some children "outgrow" untreated mild hip dysplasia and some forms of untreated dysplasia cause little or no impairment of quality of life, studies have as yet been unable to find a method of predicting outcomes. On the other hand, it has often been documented that starting treatment late leads to complications and ends in poor results. Hip replacement and osteotomy
Hip dysplasia is often cited as causing osteoarthritis of the hip at a comparatively young age.