”XO” is a familiar foreign wine, in the old days the king thanked the hall before the swallow, with the development of China’s economy, people’s living standards, but also gradually fly into more ordinary people’s homes. However, I want to talk to you is not wine, is a mysterious and important signal of the baby double lower limb development deformity: X-leg and O-leg. X-shaped legs, commonly known as “external eight legs”, medical professional name for “knee valgus”, legs naturally straight or standing, when the two knees touch, the two sides of the inner ankle joint can not come together, now teach you a new term, ankle spacing. Ankle spacing refers to the distance between the medial side of the ankle joints at this time. When both lower limbs are turned out, both lower limbs are in the shape of “X”, which is how X-shaped legs are derived, there are exceptions, that is, if only one lower limb is turned out, both lower limbs look like “K” shape, called “K “K” shaped legs. O-shaped legs, commonly known as “bow legs, loops legs, internal eight”, the medical professional name for “knee inversion”, deformity and knee valgus is the opposite of X-shaped legs, both lower limbs naturally straight or standing, the two sides of the ankle joint can touch each other, the two knee joints can not be close together. Now we will teach you a new roster, knee spacing. Knee spacing refers to the distance between the medial knee joints at this time. When the lower extremities are bent inward, an O-shaped gap is formed between the two legs, so it is called “O-shaped leg”. When the unilateral lower limbs are turned inward, the shape is like a “D”, so it is called D-shaped leg. Remember the two terms we just introduced to you? Ankle spacing and knee spacing. These two terms are indicators of inversion and valgus knee. When the knee spacing and ankle spacing are within 75px, it is mild, 3-250px is moderate, and greater than 250px is severe. So is the above performance “inversion and ectropion”? You know the answer, of course not. Clinical statistics show that it is normal for babies to have outward bending of the lower extremities in the first year, and O-shaped legs are common in the second year, and knee collisions when walking with the lower extremities at the age of 3-4, also called knee bruxism, are mostly normal. In life, how can we parents find out if our babies have inversion or valgus knees? In newborns and small infants, it is normal to have mild to moderate knee inversion. Children between the ages of 2 and 6 years old tend to have developmental knee valgus, mild to moderate knee valgus is a physiological phenomenon, while babies with severe knee valgus tend to have a wobbly gait when walking, as they walk with bilateral knee collisions and walk with their feet apart to avoid falling. The baby is easily fatigued, walks a shorter distance than other babies, and needs to be held for a short time. So how do you treat inversion and valgus knees? The main concern of mothers and fathers is how to treat inversion and valgus knees, especially if there is a good conservative treatment to avoid surgery. The usual non-surgical treatment is the use of a long-leg brace, and the familiar method of applying a padded insole on one side of the shoe is ineffective and should be avoided by many parents. Long-leg brace therapy should be reviewed every 3-6 months, although x-rays are not always required for every review. For some metabolic and endocrine diseases that cause internal and external knee valgus, the effect of brace treatment is not certain, but can bring a lot of discomfort and even sequelae. If conservative treatment is ineffective, surgery is required. Babies with inversion of the knee should have surgery if they are older, have hard bones and have a knee spacing of 250 px or more, and babies with ectropion should have surgery if bracing is ineffective. There are many specific surgical options, so we won’t discuss them here. Of course, many parents will have many questions, such as what are the pathological knee inversions and valgus? For the sake of time, here is a brief description: Most knee inversions and knee ectropion are developmental changes, and a few are caused by rickets in infancy. The causes of pathological knee entropion and knee ectropion are mainly in five categories: bone metabolism and endocrine disorders, bone development disorders, nonsuppurative arthritis, traumatic causes, and other causes. Type I: Bone metabolism and endocrine causes of internal and external knee rollover. For example, various rickets: vitamin D deficiency rickets, intestinal (abdominal) rickets (that is, rickets caused by malabsorption due to abdominal organ diseases), renal rickets (that is, rickets caused by too much loss), non-vitamin D deficiency rickets, congenital rickets, etc. The second category: disorders of bone development caused by internal and external knee, also called “osteogenesis imperfecta”, many scholars believe that this is a genetic disease. The third category: knee valgus due to non-septic arthritis. These include “osteoarthrosis”, rheumatoid arthritis, etc. Type IV: Traumatic knee valgus. The main causes are epiphyseal injuries, fractures into the knee joint, and fractures of the lower extremity diaphysis. The fifth category: other causes of internal and external knee roll. Such as cerebral palsy, polio abnormal power pull knee inversion, destructive lesions immediately adjacent to the knee joint caused by tuberculosis, infection, etc., epiphyseal osteochondrosis also known as tibial entropion, adolescent knee inversion, etc. If a baby is found to have severe internal and external knee roll, it is recommended to visit the hospital for early and definite diagnosis and early treatment, so that every step of the baby will lead to a wonderful life tomorrow.