In the clinic, I often meet young parents who come to the clinic with their little babies who are a few months old, especially those who are still in their infancy. I usually have a hunch, and of course this hunch comes from experience, that this parent must have come because the baby has an asymmetrical thigh skin pattern, or because of a sloping neck. The first time I saw a baby, I had to go to the community hospital for a checkup, and the doctor said that the baby’s thighs were asymmetrical. So, what is the problem of asymmetrical thigh skin lines in babies? Is there a problem with asymmetrical thigh skin lines? Is there no problem if the baby’s thigh skin is symmetrical? What diseases might be indicated by asymmetrical thigh skin lines? What could be the cause of this disease? What should I do if there is a problem? If these problems occur, how should I hold my baby and how should I choose the tools to hold my baby? With these questions, today I will tell you about the baby thigh skin pattern asymmetry in the end for which? First of all, to answer the first question, what is the problem of asymmetrical skin pattern of baby’s thighs? The answer is: the asymmetry of baby’s thigh skin pattern is clinically pointed to a hip joint disease called developmental hip dysplasia. So what causes hip dysplasia to occur? Current scientific research shows that hip dysplasia is a polygenic inheritance pattern, commonly seen in children born in breech position with lax joints. Of course, there are many, many other causes of hip dysplasia. The normal hip joint is mainly composed of the acetabulum and the femoral head, and if the hip joint is dysplastic, then it mainly involves the development of these two parts. When there is acetabular dysplasia, the femoral head or even the entire lower limb on the affected side will be positioned upward compared to the opposite side because the muscles around the hip joint pull the femoral head upward, and the lower limb will be shorter compared to the opposite side. Why does hip dysplasia cause asymmetric skin pattern of the thighs? There are many reasons for babies with asymmetrical thigh skin lines, but the more common and serious consequence is unilateral hip dysplasia. Both lower limbs should be symmetrical, if one side of the hip dysplasia, according to what was said earlier, the position of the affected lower limb by the upper and lower limbs of the skin pattern will appear asymmetrical. So is it a problem if the thighs are asymmetrical? Does it mean that there is no problem if the baby’s thighs are symmetrical? The answer to both of these questions is not necessarily. Many babies with asymmetrical thigh skin lines have been clinically examined and are fine. In other words, asymmetrical skin lines are not an absolute indication of hip dysplasia. At the same time, because the bilateral lower limbs of babies with bilateral hip dysplasia are positioned upward relative to normal, they do not have asymmetrical thigh skin lines. So, if there is no bilateral thigh pattern asymmetry, what else does hip dysplasia show? Newborns often do not show any symptoms of hip dysplasia, but the doctor who examines them after birth may give them a special hip test: spread their legs apart, bend them and then straighten them. If the baby’s hip joints make a “clicking” sound when moving, it is possible that both femoral heads (the upper thigh bones) are slipping in and out of the pelvic fossa. This is called clinical hip instability. Babies born with these signs are not painful or uncomfortable and often do not require treatment. Some babies are born with a normal hip test but do not develop normally. The initial signs are as follows: one leg appears slightly shorter than the other, and there may be an excess fold of skin on one thigh or hip. When changing your baby’s diaper, you may notice that one hip does not extend as far as the other. In rare cases, you may not notice congenital hip dysplasia or dislocation until your baby starts to walk, which may be characterized by a slight limp and walking on the toes of the affected side. Some babies may also have a more pronounced lumbar protrusion and their hips may stick back more than other children. If you notice any of these problems in your baby, it is important to take him to the hospital for an examination. The doctor will not only diagnose hip dysplasia through physical examination, but may also observe the development of the hip joint with the help of ultrasound and X-ray so as to find out whether your baby has any problems as early as possible. The question arises again, how old is the baby to have an ultrasound examination and how old is the baby to be examined by X-ray? This question is also a special concern for parents. After all, X-rays are harmful and they are done on the baby’s reproductive organs. First of all, I would like to tell you that the amount of radiation used in X-rays is very small, so you don’t have to worry about the effects of X-rays on your baby’s growth. Now let’s get back to the point. Before 6 months of age, the baby’s femoral head is made of cartilage, and the sound waves of ultrasound can pass through the femoral head to reach the hip joint. So why is it not possible after 6 months? The reason is: at 6 months of age, there is a bone like structure called ossification center in the femoral head, which blocks the ultrasound from passing through, so the development of the hip joint cannot be examined by ultrasound. I don’t know if this explanation is clear to everyone. Therefore, if you need to check the hip joint of a baby over 6 months old, you can only do so by X-ray. However, ultrasound does not have the effect of radiation, but it does not give a clearer and more realistic picture of the structure of the hip joint, and the ultrasound examination is influenced by the level of the doctor who performs the examination, and of course, there is a long queue for the ultrasound examination in Beijing. Many babies, who have no problems with hip development at birth, and after birth, are found to have hip dysplasia, or even hip dislocation, when they are a few months or even a few years old. So what can cause hip dysplasia? What position will be better to hold the baby? According to this, how should we choose the utensils to hold the baby? Epidemiological studies prove that the incidence of hip dislocation is more in the north than in the south, why? Due to the cold weather in the north, the baby will be rolled into a roll with a small quilt when he goes out. In this position, the baby’s hip joint is in an easily dislocated position, which is not conducive to the development of the hip joint. Over time, it is easy to develop hip dysplasia, or even dislocation. So what position is more conducive to the development of the hip joint? Many parents should have guessed. That is, let the baby’s hip joint open, like a frog open leg posture is the most conducive to hip joint development, is also the most stable position of the hip joint. In this position, the femoral head and acetabulum can be in full contact and influence each other to promote development. According to this principle, we can choose to hold the baby’s appliances. Any appliance that allows the baby to be in this position can promote the development of the hip joint. The older kind is the kind of carrier that can carry the child on the back with legs spread, and now with the development of technology, the baby waist stool is also known to everyone. The baby lumbar stool can also maintain a good hip position and promote hip development. Of course for mothers who gave birth by cesarean section, there may be greater concerns and hesitation to use a waist stool. C-section mothers need to recuperate their bodies, on the other hand, the child is not fully developed, the lumbar spine has not grown fixed, it is not appropriate to use the lumbar stool. It is generally recommended to use the lumbar stool for 7 months after delivery, during this period, the use of the lumbar stool may be pressed against the incision of caesarean section, which will cause the mother subconsciously afraid to support the baby, the mother’s waist will be tired in this case, the baby is more uncomfortable. Especially when touching the baby for a long time, the incision of the cesarean section will itch when it is attached to the fever. Therefore, it is recommended that mothers who have had a cesarean section should not use a lumbar stool during the recovery period. If you want to use a lumbar stool, it is best to wait until the baby is able to sit up alone and the mother’s wound is well healed. So what should you pay attention to before that? The first thing is not to roll the baby into a bucket-like position, and try to let the baby move both lower limbs on their own. The parents who like to observe will certainly also find that the baby likes to sleep like a little frog with legs spread. Why? Because this is the most comfortable and most conducive to hip joint development. (This article is published with the authorization of Dr. Ren Gang.)