Gluteoplasty or buttock augmentation (from Greek: , 'rump' + , 'shaped, formed, moulded') denotes the plastic surgery and the liposuction procedures for the correction of congenital, traumatic, and acquired defects/deformities of the buttocks and the anatomy of the gluteal region; and for the aesthetic enhancement (by augmentation or by reduction) of the contour of the buttocks.
The procedures for buttock augmentation and buttock repair include the surgical emplacement of a gluteal implant (buttock prosthesis); liposculpture (fat transfer and liposuction); and body contouring (surgery, liposculpture, and Sculptra injections) to resolve the patient's particular concern or deformity of the gluteal region.
Background The functional purpose of the buttocks musculature is to establish a stable gait (balanced walk) for the person who requires the surgical correction of either a defect or a deformity of the gluteal region; therefore, the restoration of anatomic functionality is the therapeutic consideration that determines which gluteoplasty procedure will effectively correct the damaged muscles of the buttocks. The applicable techniques for surgical and correction include the surgical emplacement of gluteal implants; autologous tissue-flaps; the excision (cutting and removal) of damaged tissues; lipoinjection augmentation; and liposuction reduction—to resolve the defect or deformity caused by a traumatic injury (blunt, penetrating, blast) to the buttocks muscles (gluteus maximus, gluteus medius, gluteus minimus), and any deformation of the anatomic contour of the buttocks. Likewise, the corrective techniques apply to resolving the sagging skin of the body, and the muscle and bone deformities presented by the formerly obese patient, after a massive weight loss (MWL) bariatric surgery procedure; and for resolving congenital defects and congenital deformities of the gluteal region.
Surgical anatomy of the buttocks Muscular origins and insertions
Anatomically, the mass of each buttock principally comprises two muscles—the gluteus maximus muscle and the gluteus medius muscle—which are covered by a layer of adipose body fat. The upper aspects of the buttocks end at the iliac crest (the upper edges of the wings of the ilium, and the upper lateral margins of the greater pelvis), and the lower aspects of the buttocks end at the horizontal gluteal crease, where the buttocks anatomy joins the rear, upper portion of the thighs. The gluteus maximus muscle has two points of insertion: (i) the one-third superior portion of the (coarse line) linea aspera of the thigh bone (femur), and (ii) the superior portion of the iliotibial tract (a long, fibrous reinforcement of the deep fascia lata of the thigh). The left and the right gluteus maximus muscles (the butt cheeks) are vertically divided by the intergluteal cleft (the butt-crack) which contains the anus.
The gluteus maximus muscle is a large and very thick muscle (6–7 cm) located on the sacrum, which is the large, triangular bone located at the base of the vertebral column, and at the upper- and back-part of the pelvic cavity, where it is inserted (like a wedge) between the two hip bones. The upper part of the sacrum is connected to the final lumbar vertebra (L5), and to the bottom of the coccyx (tailbone). At its origin, the gluteus maximus muscle extends to include parts of the iliac bone, the sacrum, the coccyx, the sacrosciatic ligament, and the tuberosity of the ischium.
Like every pelvic-area muscle, the gluteus maximus muscle originates from the pelvis; nonetheless, it is the sole pelvic muscle not inserted to the trochanter (head of the femur), and is approximately aligned to the femur and the fascia lata (the deep fascia of the thigh); the tissues of the gluteus maximus muscle cover only the rear, lateral face of the trochanter, and there form a bursa (purse) that faces the interior of the thigh.
Innervation The motor innervation of the gluteus maximus muscle is performed by the inferior gluteal nerve (a branch nerve of the sacral plexus) and extends from the pelvis to the gluteal region, then traverses the greater sciatic foramen (opening) from behind and to the middle to then join the sciatic nerve. The inferior gluteal nerve divides into three collateral branches: (i) the gluteus branch, (ii) the perineal branch, and (iii) the femoral branch. The first ramification—the gluteus branch—is a branch nerve that is very close to the emergence of the inferior gluteal nerve to the area, next to the inferior border of the pyramidalis muscle.
In surgical and body contouring praxis, the plastic surgeon creates the implant-pocket—either for the gluteal prosthesis or for the injections of autologous fat—by undermining the gluteus maximus muscle with a dissection technique that avoids the sacrum, the sacrotuberous ligament, and the tuberosity of the ischium; which, if accidentally cut, might isolate the posterior (back) portion of the muscle and lead to denervation, the loss of nerve function and of innervation.
Vascularization The superior gluteal artery, the inferior gluteal artery, the superior gluteal veins, and the inferior gluteal veins irrigate the gluteus maximus muscle with arterial and venous blood. The vascularization, the entrance of the blood vessels to the muscle tissues, occurs at the anterior (front) face of the muscle, very close to the sacrum. As the arteries and the veins enter the mass of the gluteal muscle, they divide into narrower blood-vessel ramifications (configured like the horizontal branches of a tree), most of which travel parallel to the muscle fibres.
In surgical and body contouring praxis, the plastic surgeon effects the implant-pocket undermining of the gluteus maximus muscle by carefully separating the muscle fibres to avoid severing the pertinent blood vessels, which would interfere with the blood irrigation of the muscle tissue. Therefore, to create an implant-pocket, either for a gluteal prosthesis or for lipoinjection, a low-angle muscle-dissection is performed in order to avoid the risk of severing any major branch—superior or inferior—of the gluteal artery, which travels very close to the sacrum and to the sacrotuberous ligament.
Surgical procedures
Surgical therapy While the resolution of the defects and deformities of the gluteal region can be realized surgically, the assessment of the degree of severity of the injury organizes treatment therapies into three types: (i) buttocks augmentation, (ii) buttocks reduction, and (iii) contour irregularity treatments that combine surgery and liposculpture (liposuction and fat-injection).
Buttocks augmentation treatments
Gluteal implants The augmentation of the buttocks is realized with a gluteal implant, which is emplaced under each gluteus maximus muscle; the insertion of the buttock prosthesis is through a midline incision (5–8-cm-wide) over the tailbone (coccyx). Augmentation with a gluteal implant is the method most effective for enlarging the buttocks of a patient whose body possesses few stores of excess adipose fat in the lower portion of the trunk, the buttocks and thighs, the anatomic regions where the human body usually stores excess body fat. Post-operatively, because of the cutting (incising) into the flesh of the tailbone muscles, the full healing of the augmented tissues can be approximately 6–8 months, in the course of which the gluteal-muscle tissues relax, and the settled buttocks prostheses are integrated to the gluteal region. The implantation procedure can be performed upon a patient who is either sedated or anaesthetized, either under general anaesthesia or under local anaesthesia. The usual operating-room time for a buttocks augmentation procedure is approximately two hours. The procedure can be managed either as an overnight in-patient treatment or as a hospital outpatient treatment. Given the nature of the surgical incisions to the gluteus maximus muscles, the therapeutic management of post-surgical pain (at the surgical-wound sites) and normal tissue-healing usually require a four to six-week convalescence, after which the patient resumes their normal-life activities.
Lipoinjection
The augmentation and contouring of the buttocks with autologous fat transfer (lipoinjection) therapy is realized with the excess adipose-fat tissue harvested from the abdomen, flanks, and thighs of the patient. In 1987 Dr. Eduardo Krulig, a Venezuelan plastic surgeon, described the technique, using the name "lipoinjection" for the first time, mentioning the regions of the body where the technique is useful. The gentle liposuction applied to harvest the autologous fat minimally disturbs the local tissues, especially the connective-tissue layer between the skin and the immediate subcutaneous muscle tissues. Then, the harvested fat is injected to the pertinent body area of the gluteal region, through a fine-gauge cannula inserted through a small surgical incision, which produces a short and narrow scar. Lipoinjection contouring and augmentation with the patient's own body fat avoids the possibility of tissue rejection, and is physically less invasive than buttocks-implant surgery. Therefore, depending upon the health of the patient, the convalescence period allows them to resume daily, normal-life activities at two days post-operative, and the full spectrum of physical activity at two weeks post-operative. Furthermore, the liposuction harvesting of the patient's excess body fat improves the aesthetic appearance of the body fat donor-sites. Nonetheless, physiologically, the human body's normal health-management chemistry does resorb (break down and eliminate) some of the injected adipose-fat tissue, and so might diminish the augmentation. According to the degree of diminishment of the volume and contour caused by the fat-resorption, the patient might require additional sessions of fat-transfer therapy to achieve the desired size, shape, and contour of the buttocks.
In common parlance, lipoinjection into the buttocks for aesthetic purposes is often called a Brazilian butt lift (BBL). This name is suggested to originate from the Brazilian surgeon Ivo Pitanguy, who pioneered the surgery in the 1960s. The popularity of the surgery significantly increased during the 2010s as a result of social media trends.
Body contouring The augmentation of the buttocks, by rearranging and enhancing the pertinent muscle and fat tissues of the gluteal region, is realized with a combined gluteoplasty procedure of surgery (subcutaneous dermal-fat flaps) and liposculpture (fat-suction, fat-injection). Therapeutically, such a combined correction-and-enhancement procedure is a realistic and feasible lower-body-lift treatment for the patient who has undergone massive weight loss (MWL) in the course of resolving obesity with bariatric surgery. In the case of the patient who presents under-projected, flat buttocks (gluteal hypoplasia), and a degree of gluteal-muscle ptosis (prolapsation, falling forward), wherein neither gluteal-implant surgery nor lipoinjection would be adequate to restoring the natural anatomic contour of the gluteal region, the application of a combined treatment of autologous dermal-fat flap surgery and lipoinjection can achieve the required functional correction and aesthetic contour.
Buttocks reduction treatments The methods for reducing the size of the buttocks include the varieties of liposuction, such as lipectomy (with and without ultrasonic enhancement) to reduce excess body fat, and superficial liposculpture, to reshape, refine, and re-establish the natural contour of the body. The usual buttocks-reduction treatment is lipectomy with applied tumescence and anaesthesia, wherein the body fat is harvested by aspiration (suction) through a small-gauge cannula (2–4 mm) that is inserted through a small incision, either to the intergluteal sulcus (the butt-crack), or to the upper area of the gluteus maximus muscle proper.