The buttocks are an essential component of female physical beauty and a vital component of the human body curve. Buttock augmentation has gained popularity among beauty enthusiasts as people’s living standards have improved, and the number of patients accepting buttock augmentation surgery is rapidly increasing. However, the number of publications on buttock augmentation is limited, and this study may be the first bibliometric analysis of published articles related to buttock augmentation in the existing literature.
From 1999 to 2021, the number of publications on buttock augmentation has steadily increased, and the USA has received high academic honours as a key contributor to buttock augmentation research. “Plastic and Reconstructive Surgery” is the most productive and co-cited journal in this field, indicating that it is the most informative resource in buttock augmentation research. Furthermore, “Aesthetic Plastic Surgery”, “Aesthetic Surgery Journal”, “Clinics in Plastic Surgery”, “Annals of Plastic Surgery”, “Journal of Plastic Reconstructive and Aesthetic Surgery” are the major journals in the field.
Cardenas-Camarena (Instituto Jaliscience de Cirugia Reconstructiva) is the most productive and co-cited author of gluteal augmentation publications (9 articles, 1.83%, 158 citations, TLS: 1993). The most co-cited article of the author, “Deaths Caused by Gluteal Lipoinjection: What Are We Doing Wrong?”, explored the causes of death from gluteal autologous fat injections and discovered that intramuscular fat injections in the buttocks and gluteal vascular injury were the primary causes of death [
8].
Furthermore, the article “Intramuscular gluteal implants”, published in “Aesthetic Plastic Surgery”, is the most frequently co-cited reference in which the authors investigated a new space to accommodate gluteal implants, namely gluteus maximus intramuscular gluteal implants. This anatomical space within the gluteus maximus muscle can accommodate larger implants, making surgery safe and providing excellent postoperative cosmetic results [
9]. This study is a great reference for the level of implant placement for buttock augmentation, which is now the main level of implant placement within the gluteus maximus muscle.
Research Hotspots
According to the analysis of the co-cited reference network shown in Fig.
8, there are currently three research hotspots in this field: experience and technology of buttock augmentation (Cluster 1, red area), autologous fat buttock augmentation and its safety (Cluster 2, green area), and buttock aesthetics study (Cluster 3, blue area).
“Experience and technology of buttock augmentation” (Cluster 1) has the largest number of publications, with articles describing surgical techniques and sharing experiences in buttock augmentation. In the second most co-cited article, Gonzalez et al. [
10] presented the “XYZ technique”, which is worth promoting since it allows for safe intragluteal muscle separation based on anatomical localization points, allowing for a perfect implant space and avoiding complications. In the fifth most co-cited article, González-Ulloa et al. [
11] presented a follow-up study of patients who underwent gluteomyoplasty ten years ago, including patients with unilateral gluteus atrophy and bilateral improvement of gluteal shape, and discovered that all patients maintained good gluteal shape ten years after surgery, with the satisfaction of both patients and physicians. Furthermore, Serra et al. [
12] detailed the fundamentals of gluteal anatomy and gluteal augmentation techniques to help plastic surgeons perform gluteal augmentation by identifying anatomical reference points.
“Autologous fat grafting for buttock augmentation and its safety” (Cluster 2) has shown that fat grafting to fill the buttocks, in addition to buttock augmentation with implants, is a popular procedure. Toledo et al. [
13] described a thirty-year experience in Brazil with buttock augmentation by fat grafting by removing the arm, back, waist, and abdominal fat. The fat was processed, centrifuged, and injected for transplantation into the buttocks with good therapeutic effectiveness. Roberts et al. [
14] used autologous microfat grafting to address the external part of the buttocks and external thighs that could not be improved by implants. This method achieved excellent outcomes. The articles with the third and fourth highest number of co-cited articles reported analysis of fat injections in the gluteal region that resulted in death, with all patients dying due to fat embolism. It also suggested that fat injections should be administered slowly, in small amounts, repeatedly, and in multiple planes, avoiding injections into the deep muscle planes of the gluteus maximus [
8,
15].
The “Buttock Aesthetics Study” (Cluster 3) demonstrated that plastic surgeons and beauty enthusiasts are exploring the aesthetics of the buttocks. A full and well-rounded buttock is a defining trait and one of the secondary sexual characteristics of women. In 1993, Singh et al. [
16] conducted an in-depth study on female body aesthetics and concluded that a waist-to-hip ratio of 0.7 was a widely accepted aesthetic criterion. According to body surface markings, Cuenca-Cuerra et al. [
17] proposed a set of aesthetic criteria where the greater trochanter of the femur was labelled A, the most prominent point of the pubic mound was labelled B, the most prominent point of the buttocks was labelled C, and the anterior superior iliac spine was labelled D. The study also concluded that the ideal buttock form is AC:AB equals 2:1. Subsequently, Cuenca-Cuerra and Lugo-Beltran [
18] concluded that a ideal buttock should have four “depressions”: the lateral depression, the short inferior gluteal fold, the superior gluteal fossa, and the V-shaped groove at the sacral triangle. Mendieta CG et al. [
19] proposed a more comprehensive aesthetic assessment system and classified buttock morphology into four types: A, V, circular, and square.
Research Trends
According to the keyword timing (Fig.
11), the research trends include the following: silicone implant, safety, satisfaction, and autologous fat grafting.
In North America, the law forbade silicone implants for buttock augmentation, and hence, only elastic implants were used. However, patients often complained of discomfort because the implants were too hard [
20]. Although breast implants can also produce better buttock augmentation outcomes, their capsule membranes have shown to be weak and prone to rupture and leakage [
21,
22]. Nowadays, with a full range of buttock implants, including circular and anatomical shapes, glossy and frosted surfaces, silicone rubber, and silicone gel, the development of buttock augmentation surgery has been as complete as that of breast implants [
23,
24]. It is expected that further research will be conducted in support of silicone buttock implants in the future.
Safety is a priority concern for patients seeking beautiful buttocks simultaneously. Cárdenas-Camarena et al. [
8] analysed and reported the causes of death due to buttock fat injections performed in Mexico and Colombia. A total of 13 of the 64 deaths related to liposuction reported in Mexico were caused by buttock fat injections, while nine deaths in Colombia were caused by fat embolism. Mofid et al. [
15] also reported on the mortality of buttock fat grafting and detailed some techniques to improve the safety of the procedure. Furthermore, complications of buttock augmentation surgery are also within the scope of safety examination. Incisional dehiscence is the most common complication following buttock augmentation with implants. In the published literature, Sinno et al. [
25] collected 2375 cases of buttock augmentation, with a 9.6% incidence of postoperative incisional dehiscence. Another study has shown incidences of incisional dehiscence up to 30% after buttock augmentation with implants [
26]. Cárdenas-Camarena et al. [
27] showed a 4.4% probability of seroma after buttock augmentation. The rate of infection after buttock augmentation with implants was 3.2% [
28]. The overall incidence of implant displacement, ectopic position, rotation, or buttock asymmetry was about 2.3% [
24]. The incidence of contracture of the buttock implant envelope was 3.5% [
29]. Condé-Green et al. [
30] performed a meta-analysis of postoperative complications in 4084 patients who underwent autologous lipofilling of the buttocks. The incidence of each complication was seroma (2.40%), rash (1.30%), pain (0.76%), morphological abnormalities (0.64%), and fat necrosis (0.56%), in that order.
Satisfaction, the ultimate criterion for evaluating the outcome of buttock augmentation, is closely related to safety, complications, and postoperative experience of the procedure. With the increasing number of buttock augmentation procedures, there is an urgent need to explore a standardized method for measuring patient satisfaction.
First reported in 1990 by Chajchir without a detailed description of the case, autologous fat grafting for buttock augmentation is an evolving field [
31]. Subsequently, the use of autologous fat grafting for buttock augmentation has been reported successively [
32,
33]. Currently, for patients with lateral thigh depressions that cannot be covered by implants, autologous fat grafting of the buttocks has become the predominant buttock augmentation approach. Its most significant advantage is that the entire buttock can be finely shaped by liposuction and fat injection, with few complications and minimal surgical scarring [
34]. According to the American Society for Aesthetic Plastic Surgery 2018 data, 94% of buttock augmentation procedures are autologous fat-filled buttock augmentation, and only 6% are implants [
35].
Strengths and Limitations
The study assessed the current status of buttock augmentation research, research hotspots, and research trends through bibliometric analysis. However, there are some limitations in the study; the analysis of this study retrieved content only from the English language publications in the WOSCC database, causing language bias; this study has omitted publications that are not included in the WOSCC database. Furthermore, with the increased number of publications related to buttock augmentation in recent years, some newly published high-quality publications have low citation frequency and are easily missed.