Dislocated load bearing surfaces lead to increased and unusual wear,  although there are studies that contradict these findings (see). Peri-acetabular osteotomy (PAO) surgery can be used to realign the hip joint in some adolescents and adults. Subsequent treatment with total hip arthroplasty (hip replacement) is complicated by a need for revision surgery (replacing the artificial joint) owing to skeletal changes as the body matures, loosening/wear or bone resorption. Hip resurfacing is another option for correcting hip dysplasia in adults. It is a type of hip replacement that preserves more bone, and may work for younger hip dysplasia patients.Osteotomies are either used in conjunction with arthroplasty or by themselves to correct misalignment. Epidemiology
Determining the incidence can be difficult. In addition there is a wide margin in diagnostic results. A German study comparing two methods resulted in twice the usual rate for one method. The condition is eight times more frequent in females than in males.Native Americans are more likely to have congenital hip dislocation than any of the other races. The risk for Native Americans is about 25–50 in 1000. The overall frequency of developmental dysplasia of the hip is approximately 1 case per 1000 individuals; however, Barlow believed that the incidence of hip instability in newborns can be as high as 1 case for every 60 newborns, with the rate dropping to 1:240 at one week. History
The Frejka pillow splint was named after Dr. Bedrich Frejka (1890-1972), a Czech orthopedic surgeon.
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.