Implants vs. Fat Injection

Not overlooked in the appreciation of human form is the appearance of one’s butt. A few years ago, an entire book was devoted to the human butt. Several years ago, butt cleavage made its debut among female singers, thankfully this does not appear to be catching on. Buttocks have some of the same qualities making them look good in men and women—full cheeks, definition and skin tone.


There are important safety considerations when performing buttock fat injection. The fat must be injected only into the subcutaneous plane above the muscle. In the past, deep injections into the muscle have been used. However, this method has been linked to fat emboli, which can be a fatal complication caused by fat globules entering the large deep veins of the buttocks. I have used ultrasound in the operating room to confirm that tangential injection of the fat, just under the skin, stays superficial.

Buttock Implants – High Complication Rate

Unfortunately, implants have a higher rate of complications when used in the buttocks than when used in the breasts. These include wound opening (“dehiscence”), infection, seromas, capsular contractures, and malposition. They can produce an unnatural appearance. Most surgeons avoid using buttock implants, and opt for fat injection instead.

Reasonable Expectations

It is not unusual for women to show me photos of desired results on their mobile devices. Sometimes these show results that are exaggerated or simply not possible in view of the amount of fat available for transfer. Also, one needs to be careful not to be too aggressive and produce contour deformities (divots) in the areas where the fat is removed.

In Combination with Liposuction and/or Tummy Tucks

In the past, liposuction was usually done alone, without fat transfer. The fat that was removed was simply discarded. Today, this fat is often used where it is needed – in the face and in the buttocks. It is common to perform buttock fat injection at the same time as a tummy tuck. The lower abdomen (the area removed by the tummy tuck) is first treated with liposuction to remove fat. This fat removal adds to the volume of fat available for buttock injection. Additional donor sites (such as the arms and bra fat) also add to the volume available for buttock injection. Usually the more fat we can obtain by liposuction the better because some of the injected fat is absorbed by the body (about a third).


Properly-performed liposuction can improve the appearance of the buttocks by reducing excess fat from adjacent areas. Liposuction must be done with the eye of a sculptor to achieve attractive buttocks. The center of the buttock is treated very conservatively, if at all. No one wants a “flat butt.” Most of the liposuction is done around the periphery of the buttocks—the flanks and the back of the thighs. This can give the illusion of tighter, more rounded buttocks. For both women and men, reduction of “love handles” will accentuate the buttocks. This is an illusion that works well to give more of an hourglass figure in women, and improves the appearance of the male butt. The improvement in buttock shape is evident in postoperative photographs of patients treated by liposuction.

Fat Injection

The buttocks lend themselves nicely to fat injection. In the past, fat obtained by liposuction was usually discarded. We now recognize that there is a limited amount of fat cells available and it is a shame to discard this limited resource if it can be put to good use. It is becoming much more common now to save this fat and inject it where we want it.


JS 23.
Procedure: Liposuction of abdomen, flanks, inner thighs, arms and axillae, and buttock fat injection.

Before, 3.5 months.


AM  25.
Procedure: Liposuction of lower body, arms, and axillae, and buttock fat injection, and excision of skin lesion of right thigh.

Before, 1 month.


BL 26.
Procedure: Liposuction of abdomen, flanks, arms, and axillae, and buttock fat injection, and touch up 4.5 months later.

Before, 2.5 months after her second fat injection procedure.


BS 30.
Procedure: Liposuction of abdomen, flanks, and inner thighs, and buttock fat injection.

Before, 1 month.


AH 32.
Procedure: Liposuction of abdomen and flanks, and buttock fat injection.

7 months.

The areas to be injected are marked before surgery. Also, the donor sites, where fat will be harvested, are marked. The donor sites are the areas of fat excess, which almost always includes the flanks because the subtraction of fat from these areas helps to accentuate the curve of the buttocks. The other typical donor areas are the tummy and thighs.

The LipiVage or Filtron System acts to separate the fat out while it is being suctioned. The fat is injected into the central part of the buttock, measuring to make sure equal amounts are injected on each side. Usually the fat is injected using the same incisions used to perform liposuction of the flanks, so there are no additional scars. Often the lateral gluteal areas (“hip dips”) are also filled in with fat to accentuate an hourglass figure.


The fat is injected evenly in tunnels using a radial technique and measuring both sides. This helps to ensure symmetry. Contour irregularities are unusual. If present, a touch-up fat injection may be recommended.


The buttocks may be treated later on with another fat injection. I have not encountered a patient who thought she had too much fat injected in her buttocks (which might be remedied by liposuction), but I have had patients who wish there were more volume and these patients may consider a second procedure.


Occasionally an abscess may form after buttock fat injection. This is treated with antibiotics and with an incision to release fluid.

Fat Emboli

Penetration of the deep veins of the buttocks can cause a very serious and deadly complication – fat emboli. This problem may be avoided by injecting fat superficially, above the muscle, where there are no large veins.

Instructions for the areas treated by fat injection are identical to those postoperative instructions which are found in the Liposuction section. In fact, most patients having buttock fat injection also have liposuction because (i) it is necessary to harvest fat from another location and (ii) fat reduction in areas such as the flanks and thighs help accentuate the enhanced fullness of the buttocks, complimenting the figure.

Avoid prolonged pressure on the buttocks. The pressure should be evenly spread out. Get up frequently. Avoid sitting for long periods.

Q: How much of the fat that you inject will take?

A: An ultrasound study performed at our clinic showed that about 66% of the fat takes (a third is absorbed by the body). Fat take varies from patient to patient. Most of the swelling is gone in 1 month and any fat that is going to be absorbed has likely been absorbed by then.

Swanson E. Prospective controlled study of buttock fat transfer using ultrasound and photographic measurements. Plast Reconstr Surg Glob Open 2016;4:e697.

Q: What will happen if I gain weight?

A: Because there are now more fat cells in the buttocks, your buttocks will be fuller at any weight. If you gain weight you will notice these areas become fuller, along with other areas of the body. At a reduced weight, they will go down, but remain fuller than if you had not had fat injection.

Q: Can you freeze fat and inject it later?

A: No. Freezing causes the fat cells to die. It is surprising for me to sometimes see a surgeon advocate freezing fat. There are also risks involved in storage and proper patient identification, like a blood bank.

Q: Do I have to avoid sitting?

A:No, you can sit, but get up frequently and sit a little forward to avoid pressure where the fat has been injected.

Q. When can I resume exercising?

A: One month after surgery.

Q: Can I have a tummy tuck at the same time?

A: Yes. In fact doing so saves an operation (that would otherwise be needed if they were done separately) and adds available fat for injection that is removed from the lower abdomen as a consequence of the tummy tuck.