For women in today’s society, the probability of being born with straight legs is not really high. In addition to genetic factors, acquired lifestyle habits are crucial. The probability of having straight legs can be reduced by learning to dance or by exercising over the years to reduce the accumulation of fat where it should not be. But with today’s society that places more emphasis on literature than martial arts, the probability of being born with straight legs can be considered small and small. And those rare sexy straight legs are even more rare to find. There is a classic saying in our hospital: “The first realm of thigh liposuction is to seek volume, the second realm is to seek flatness, and the third realm is to seek straightness.” In other words, the first concern of the entry-level liposuction surgeon is the amount of fat sucked out, and the middle level liposuction surgeon is most concerned with the balance of subcutaneous fat, that is, the fat layer in each local part is as thick as possible to prevent unevenness. For the most advanced liposuction, the most important thing is the overall contouring, especially for thigh liposuction, straightness is the highest pursuit. The reason why “straight” is the highest pursuit is that straightening the thighs through liposuction is not a simple matter, it requires the doctor to have a good global view and use different liposuction strategies in different thigh areas. It also requires consideration of the degree of skin retraction in different areas of the patient, and most problematic of all, because each patient has a different fat distribution, the fat thickness in each area should be specialized if you want to straighten your legs. The thickness of fat in different areas usually varies greatly, and the transition between these different areas must be even and natural in order to achieve the maximum “straightness”. Here is a brief introduction to the basic knowledge and principles of the so-called “thigh straightening” procedure. Women’s fat distribution usually has a certain pattern. As shown in Figure 1, the inner thighs often form an unattractive three-way curve. The root of the thigh and the inside of the knee are easy to form fat accumulation, for some girls with high fat content, the fat accumulation at the root of the thigh will cause friction when walking, causing inconvenience to life at the same time, in the long run, the skin at the friction will form discoloration, greatly affecting the appearance. The inside of the knee is another fat accumulation disaster area, this area of the fat caused by the thighs and calves between the curve of the poor articulation, is another killer of straight legs.