Developmental Dislocation of the Hip
Developmental dislocation of the hip, more commonly know as DDH, is synonymous with congenital dislocation of the hip (CDH). This is a pediatric orthopedic problem in which a newborn or toddler is discovered to have a hip (occasionally bilaterally-20%) that is not in the socket; this is termed subluxed (partial contact with the pelvis) or dislocated (no contact with the pelvis). The incidence is approximately 1:1000 live births. Girls have a 6:1 ratio of presentation compared to boys. A breech presentation also is a risk factor for DDH. DDH should not be confused with teratologic hip dislocation, which is diagnosed in-utero.
The cause of DDH is thought to be associated with in-utero positioning of the fetus; other commonly linked conditions include torticollis and metatarsus adductus.
If left untreated, or undiagnosed, DDH can lead to the development of both hip dysplasia and osteoarthritis later in life, as well as painful disability and a limp.
DDH is usually suspected when a pediatrician examines the child during a well baby exam; formal diagnosis is then made by ultrasound and/or radiographs (xrays), at which point pediatric orthopedic consultation and referral is sought.
Treatment of DDH includes non-operative (bracing, harness) and operative means (specialized osteotomies).
Treatment of DDH is age-dependent; If discovered within the first year of life, bracing is usually recommended in the form of a Pavlik harness; this harness works by keeping the leg(s) in a knee-separated position (abduction); children are left in the brace for up to a month at a time. Overall, Pavlik harness splinting has a success rate of ~90%, but again, success is age-dependent. It should be mentioned that bracing with the harness is not indicated for neurological causes of DDH, such as spina bifida and/or cerebral palsy. Other non-operative options include spica casting for up to 6 weeks.
If non-operative methods fail to reduce the hip into a normal position, surgery is then considered, at around 2 years of age.
The surgery is an open procedure in which the hip is reduced into the socket. A pelvic, and sometimes, femoral osteotomy is required to ensure good coverage; If the dislocation is severe, a small shortening of the femur is sometimes required; however this has a minute effect on overall limb length discrepancy later in life, as during skeletal growth, the bone remodels and eventually equalizes the length.
During the surgery, a ligament that normally holds the hip in socket is usually constructed (ligamentum teres). (This is an artificial ligament that needs to be removed later as well as screws that are placed during the original surgery during a brief outpatient procedure.) As this is an open procedure, and both the pelvis and femur bones are broken (osteotomy) in order to facilitate the correction, there exists a high likelihood that a blood transfusion is required either during the surgery, or later on the pediatric floor.
At the conclusion of the surgery in the operating room, a spica cast is placed; this can be either a removable or non-removable cast. The decision as to casting is made by the surgical team in the surgery based on final post-operative x-rays. A 3-4 day hospitalization stay is needed, and a wound check at one week after surgery is done in the clinic with our orthopedic technologists and physician assistants; the cast is then converted into a removable clamshell, if applicable.
Six weeks after surgery we recommend either an in-clinic visit with cast-off x-rays or to send us cast off x-rays from the families hometown; in either case the x-rays will be reviewed and if adequate healing is present, we will discontinue the cast and recommend physical therapy be started to re-strengthen the hip and leg muscles.
We have the one of the largest and most successful experience with the surgical management of hip dysplasia and dislocated hip in Florida and the US.