Hybrid Buttock Augmentation:
Can a Flat Buttock and the Pelvic Line Be Changed Together?

Why does the buttock look flat?

When thinking about buttock augmentation, the first thing that comes to mind may be "how big should I make it?"

But the actual impression of the buttock is not determined by size alone. The overall silhouette changes depending on where the buttock's highest point sits from the side, and what curve it forms from pelvis to thigh from behind.

For example, if the center of the buttock lacks volume, the profile can look flat, and if the hip dips on the sides of the pelvis are deep, the pelvic line from the front or back can

look hollow.

Conversely, even if the buttock itself is not small, if the boundary between waist and pelvis is not distinct, the overall body can feel straight.

So in buttock augmentation, rather than simply adding volume, it is important to first

identify which part of your current body makes the buttock look small or flat.

Which body types are suited to hybrid buttock augmentation?

Hybrid buttock augmentation can be considered when you want to improve both buttock projection and the surrounding pelvic line, rather than when only one area lacks volume.

In particular, if the center of the buttock is flat and the hip dips on both sides are also hollow, filling only one area may not create the desired silhouette.

The core of the hybrid approach is designing the volume needed in the center and around the periphery separately.

Buttock augmentation itself is used not just to increase size but to adjust volume, roundness, projection and overall body balance.

How does hybrid buttock augmentation design the body?

In hybrid buttock augmentation, we first identify separately where volume is needed in the current buttock.

An implant can be used where central projection is lacking, and your own fat where lines need fine connecting, such as hip dips or the outer buttock.

What matters here is not simply performing both methods at the same time.

For example, if projection is sufficient in profile but the sides are hollow, the surrounding contour may be weighted more; conversely, in a slim body lacking buttock volume, central volume may be planned as the priority.

Using fat also requires harvesting it from the abdomen, flanks or thighs. Refining unwanted volume on the waist or flanks in this process lets the plan create a sharper contrast from waist to pelvis, not just change the buttock itself. Combining liposuction with buttock fat grafting to adjust the torso and buttock contour together is also used.

Ultimately, hybrid buttock augmentation is surgery in which what matters is less "how much to put into the buttock" and more where to reduce, where to create the center, and which curves to connect.

In a meta-analysis of 13 studies on combined implant-and-fat buttock augmentation, the implant removal rate was 1.70%, and complication rates differed by the plane in which the implant was placed.^[1]

Related readingWhich areas the implant and fat each handle is covered in "Hybrid buttock augmentation: how is a natural pelvis and hip line created?" (Korean).

Why do surgical plans differ even for the same desired buttock shape?

Even if people look at the same photo and want the same hip line, not everyone can be operated on the same way.

This is because pelvic width, buttock size, skin elasticity, current fat, the depth of hip dips and left–right asymmetry differ from person to person. When deciding on a buttock augmentation method, current buttock size and shape, the amount of fat available from liposuction, and skin quality and elasticity are considered together.

Especially in the hybrid approach, how much of a role the implant and fat each play must be adjusted to the body.

In a slim body, the amount of usable fat must be checked first; in a body with enough fat, we can also consider which harvest sites will naturally refine the overall body line.

When buttock fat grafting is included, a safe surgical method — confirming the plane into which fat is injected — matters as much as design. Relevant plastic surgery societies recommend injecting fat into the subcutaneous layer above the gluteal muscle fascia and using ultrasound to confirm the injection site in real time.

So in hybrid buttock augmentation, rather than first deciding a specific implant size or fat volume, the process of analyzing the current body and then deciding each role to fit the desired silhouette is needed.

In a systematic review of 44 studies on buttock augmentation, overall complications were 21.6% with implants and 9.9% with fat grafting. Because the common complications of the two methods differ, hybrid must manage each risk separately.^[2]

Hybrid buttock augmentation: common myths and facts