Developmental dysplasia in the hip is the anatomical abnormalities of the hip joints in which the head of the femoral bone shows an abnormal relationship with the acetabulum. It includes several risk factors like first born status, female sex, positive family history breech presentation and oligohydraminos. Clinical presentations of the developmental dysplasia of hip depend on the age of the child. Generally it has been found that children born with hip disability, hip instability infants having limited to hip abduction on examination and older children with limping, joint pain and even sometimes osteoarthritis. Repeated careful testing of the children after the birth till their growing process should be continued. It can also include the provocative testing. Other similar symptoms that are visible in normal eye includes shorting in length of the femur with hips and knees flexed, asymmetry of the gluteal or thigh bones and discrepancy of leg lengths in potential clues. Treatment are mainly dependent on age presentations and outcomes are much better when the child is treated early particularly during the six months of age.
The term of development of dysplasia of the hip has replaced the congenital dislocation of the hip as it describes the full range of abnormalities affecting the immature hip more accurately. In some children the normal femora- acetabular relationship can be seen during the birth but latter on dysplasia or abnormalities are observed latter on.
It can be well defined as any kind of deformity in the shape, size or the orientation of the femoral head, acetabulum or both is often referred as dysplasia. It has been seen that majority of the abnormalities result due to maldevelopment of the acetabulum. The problem of femoral head is a secondary concern that results in non-physiological biomechanics from the anteverted acetabulum or as a result of treatment. The instability of the hip occurs when it fits tight between the femoral head and the acetabulum is lost and the femoral head is able to move within or outside those confines the acetabulum. Generally the dislocated hip has no contact in between articular faces of the femoral head and the acetabulum. Generally the dislocated hip has no contact of the femoral head and the acetabulum. Teratology dislocation generally shows marked difference in the hip joint at the time of birth. It also includes other malfunctions such as spina bifida, arthrogryposis multiplex congenita, lumbosacral agenesis, chromosomal abnormalities, diastrophic dwarfism, Larsen syndrome and other rare syndromes.
The incidence of the developmental dysplasia of hip is really difficult to monitor because of the discrepancy in definition of the condition, type of examination used and different levels of skills of clinicians. The range of incidence includes as low as 1000 to as high as 34 per 1000. During ultrasound high incidences are reported which are also used in clinical examination. Several risk factors including first born status, female sex positive or not, family history, breech presentation and oligohydramnios.
The several causes of the Developmental Dysplasia are multi factorial in nature. There are certain factors that lead to the development of dysplasia in hip which includes the ligament laxity, postnatal positioning and primary acetabular dysplasia. Hereditary ligament laxity and other neuropediatric disorders with an abnormal muscle tension, such as cerebral palsy, myelomeningocele and arthrogryposis, are the major factors for the inheritance of developmental dysplasia of hip. It also increased incidence of developmental dysplasia of hip in identical twins as compared to fraternal twins. It also suggests several genetic influences. Female new-borns are more prone to develop developmental dysplasia of hip. This is because as they respond to maternal relaxing hormones which may cross the placenta and induce laxity.
It may also happen that intrauterine crowding also affects the developing hip in the placenta. There evolves the increased incidence of developmental dysplasia in hip in infants who are born in breech presentation, most notably when the knees are extended. There are 9 other factors which include first born child and oligohydramnios. In addition, postnatal positioning also plays a role in the development of developmental dysplasia in hip. A very high incidence of developmental dysplasia of hip is reported in babies wrapped with the hip in extended position. It is as compared to the babies wrapped in flexed and abducted position. Also, a permanent supine position of new-borns which can reduce the risk of sudden infant death seems to increase the risk of developmental dysplasia in hip.
A careful clinical examination should be carried out on all new-born children especially those with risk factors for developmental dysplasia in hip. For the purpose of examination of an older child also includes careful assessment of extremities for asymmetric skin folds or leg length discrepancy in case of unilateral hip dislocation. A positive Galeazzi sign is another indicator of hip dislocation. It is depicted by laying the child supine and flexing both hips and knees. It also provides positive sign is indicated by an inequality in the height of the knees. Certain limited abduction may be particularly helpful in diagnosing children with bilateral hip dislocation because the Galeazzi sign will be negative. The maximal abduction of hips should be greater than 60°.In neglected cases, developmental dysplasia in hip may be diagnosed when children approach walking age with a limp on the affected side (positive Trendelenberg’s sign) and hyperlordosis.
The treatment of developmental dysplasia of hip is age-related. It is the goal is to achieve and maintain concentric reduction of the femoral head into the acetabulum. The best outcome can be expected only if the treatment is started at a very early age. This has been achieved in the developed world through improved awareness and training. The increased surveillance (use of ultrasonography), and quicker access to paediatric orthopaedic surgeons including 21 of them. It must be noted that there are very few specialized paediatric orthopaedic surgeons in the developing world, and fellowship programs for paediatric orthopaedic surgery should be initiated to cater the needs and requirement. Therefore this in addition to the myriad of other paediatric orthopaedic conditions.