What is developmental hip dysplasia?
Developmental dysplasia of hip (DDH) is one of the most common diseases in infant skeletal systems. It is a general term for a series of hip abnormalities that occur when a baby is born or continues to develop after birth, including hip dislocation, subluxation, and acetabular dysplasia.
The hip joint is a ball and socket joint that is connected by a peripheral ligament, where the "ball" is the femoral head and the "wolf" refers to the acetabulum. This configuration allows the femoral head to be firmly embedded deep into the acetabular fossa (see above).
The abnormal acetabulum will gradually become shallower and triangular, resulting in the femoral head not being deeply embedded in the acetabulum, and the pressure is more than doubled than normal. The articular cartilage surface wears and degenerative lesions occur for a long time (see left 1 in the figure above). If the acetabulum becomes shallow enough to accommodate the femoral head, the femoral head will slip out of the acetabulum, which is dislocated (see right, left 2, right 2 above).
There are no definitive conclusions about the cause of DDH. Current breech pregnancy or production, family history of DDH or genetic history (ie, DDH in one parent or sibling), first child, baby girl, and oligohydramnios are recognized as high risk factors for DDH.
Among the areas or ethnic groups that have a habit of "candle packs" for newborns or bundled baby calves, DDH is high, such as Indian tribes in North America and parts of northern China. On the contrary, in Africa or parts of southern China, the incidence of DDH is significantly lower due to the hot weather and the area where children like to separate their lower limbs.
The North American Indian tribes like to carry the baby back with a "boat" and tie the baby's legs tightly with a rope. This habit has led to the fact that North American Indian tribes have become one of the highest incidences of DDH worldwide.
The "candle bag" that the northern part of China likes to use, straightens the baby's limbs, and wraps it with a bag, and the outside is tightly tied with a rope. The habit of using "candle packs" has led to a higher incidence of DDH in northern China than in the south.
The Children's Hip Developmental Abnormality Screening Center under the Tianjin Women and Children's Health Center conducted hip joint screening for 10262 infants in Tianjin from June 2009 to May 2010. The results showed that the abnormal detection rate of hip ultrasound in infants with lower limbs was significantly higher than that in the uncoated group (see table below).
What are the consequences of DDH?
In infants and young children, DDH has no symptoms and no pain, which is also a feature that DDH does not easily find. If it is only mild dysplasia, it usually takes pain in early teens and adults. If it is severe dysplasia (complete hip dislocation), then the baby will walk and find a limping or body swing like a duck walking.
In the domestic children's orthopaedic unit disease spectrum, DDH has always occupied the first place in limb malformation diseases. At present, domestic and foreign scholars agree that the key to the efficacy of DDH is early diagnosis and appropriate treatment. If the disease can be detected early and treated early, it can develop into a normal hip joint. If the best time to miss treatment is difficult to correct the joint deformity and leave a lifelong disability.
If DDH is started in the neonatal period, it can be completely restored without leaving sequelae. If the baby is still not cured when he is 18 months old, surgery can only be used, and as he gets older, the risk is higher, the difficulty of surgery will be higher, and the treatment effect will be worse.
Therefore, regular physical examination and screening of DDH in newborns has become an important part of newborn screening in many countries.
How to protect the baby's hip joint?
When a healthy baby is born, the baby's hip joint is flexed. Like a frog, don't expect the baby's hip joint to be as straight as the adult. As the mother's residual hormone levels in the baby gradually decrease, the hip flexion position will make the hip joint capsule more robust and powerful. Babies will have enough time to stretch the hips before they start walking. This natural method has been used in Serbia and Japan and helps the baby avoid hip dysplasia.
When the baby's two legs are in the abducted flexion position, the femoral head is more securely embedded in the acetabular fossa. In this case, it will promote the normal development of the acetabular fossa (see the figure below).
When the baby's legs are close together, the femoral head may slip out of the acetabular fossa, and the buttocks muscles will be pulled down, which will increase the pressure on the articular cartilage and eventually lead to hip dysplasia (see the figure below).
Some baby products may affect the normal development of your baby's hips, such as baby carriers, sleeping bags, safety seats, clothing, cradle, etc. These products unconsciously put the baby's hips in an unhealthy position during use, posing a potential risk of hip dysplasia, especially for long-term use. Mom and Dad need to pay attention to this problem when choosing some daily necessities for their baby.
Left: This baby carrier will force the baby's legs together and may cause hip dysplasia, which is not recommended.
Right: This baby carrier will support the baby's thighs and keep the hips in a stable state. It is recommended.
Left: When the baby is sitting in the safety seat, the two legs need to be close together and are not recommended.
Right: The loose safety seat keeps your baby's hips in a healthy position and is recommended.
In short, don't wrap your baby too tightly or leggings. Give your baby a pair of clothes that can be separated from the lower limbs. When using a safety seat or a harness, choose a product that will keep your baby's hips in a healthy position. The ultimate goal is to let the baby Your baby's lower limbs can move freely to promote healthy hip development.