Structural Gender Dimorphism and the Biomechanics of the Gluteal Subcutaneous Tissue: Implications for the Pathophysiology of Cellulite

Abstract

Background: This study was performed to investigate gender differences in gluteal subcutaneous architecture and biomechanics to better understand the pathophysiology underlying the mattress-like appearance of cellulite. Methods: Ten male and 10 female body donors [mean age, 76 ± 16.47 years (range, 36 to 92 years); mean body mass index, 25.27 ± 6.24 kg/m2 (range, 16.69 to 40.76 kg/m2)] were used to generate full-thickness longitudinal and transverse gluteal slices. In the superficial and deep fatty layers, fat lobule number, height, and width were investigated. The force needed to cause septal breakage between the dermis and superficial fascia was measured using biomechanical testing. Results: Increased age was significantly related to decreased dermal thickness, independent of sex (OR, 0.997, 95 percent CI, 0.996 to 0.998; p < 0.0001). The mean number of subdermal fat lobules was significantly higher in male body donors (10.05 ± 2.3) than in female body donors (7.51 ± 2.7; p = 0.003), indicating more septal connections between the superficial fascia and dermis in men. Female sex and increased body mass index were associated with increased height of superficial fat lobules. The force needed to cause septal breakage in male body donors (38.46 ± 26.3 N) was significantly greater than in female body donors (23.26 ± 10.2 N; p = 0.021). Conclusions: The interplay of dermal support, septal morphology, and underlying fat architecture contributes to the biomechanical properties of the subdermal junction. This is influenced by sex, age, and body mass index. Cellulite can be understood as an imbalance between containment and extrusion forces at the subdermal junction; aged women with high body mass index have the greatest risk of developing (or worsening of) cellulite.

Subcision™ plus poly‐l‐lactic acid for the treatment of cellulite associated to flaccidity in the buttocks and thighs

“…confirmed the existence of two types of septa: one more superficial and thinner, which divide the adipocytes; and the other thicker and longer, which is more deeply inserted into the muscular fascia. This latter type consists of a more resistant fibrous band, containing a vascular‐nerve bundle, which is responsible for the deeper depressions seen in cellulite . The presence of the vascular‐nerve bundle explains the formation of more extensive ecchymosis and bruising following Subcision™.…”

“…Hemosiderosis was the most frequently encountered adverse event in this sample, which is consistent with our experience performing Subcision™ alone. Post‐Subcision™ hemosiderosis may be caused by the extensive ecchymosis resulting from the disruption of the thick fibrous septa containing the vascular‐nerve bundle, or by the wider surgical trauma required in patients that have extensive post‐traumatic fibrosis. In addition to the previously described preventive measures for controlling the extent of the ecchymosis (postoperative compression, use of anesthetics with vasoconstrictor, iron intake control, etc), the author recommends the use of pulsed intense light in cases where hemosiderosis persists for more than 3 months, which did not occur in any patient in this sample.…”

“…Subcision™ was performed on the deep depressions, visible in the standing position and with the muscles relaxed, prior to PLLA injections, and only in the first treatment session, following the current technique, described below: After skin antisepsis with chlorhexidine, a local infiltrative anesthesia (lidocaine 2% with phenylephrine) was injected into the subcutaneous level of all the marked depressions. An 18G BD Nokor™ (Becton Dickinson Co., New Jersey, USA) needle was inserted at a 45‐degree angle until 1.5‐2 cm under the depression, through a puncture in the skin surface. The needle was positioned from the right to the left, with the blade turned to the left. With gentle manual movements, the larger and deeper subcutaneous fibrous septa were cut. After all the fibrous septa were released, compression was applied for 5‐10 minutes, to achieve early hemostasis. After the compression, the patient received PLLA injections. …”

Human Pharmacokinetics and Safety of Subcutaneous Collagenase Clostridium Histolyticum in Women

“…ellulite is a localized alteration of skin topography (eg, dimpling) and affects 80% to 98% of postpubertal women of all ages and ethnicities. 1,2 Although the pathophysiology of cellulite has not been fully elucidated, data suggest the number, type, and orientation of the collagen-rich (fibrous) septae play a primary structural role. 1,3 Other factors may include subcutaneous (SC) edema and fibrogenesis; SC adipose protrusion; and decreased dermal thickness with age.…”

“…1,2 Although the pathophysiology of cellulite has not been fully elucidated, data suggest the number, type, and orientation of the collagen-rich (fibrous) septae play a primary structural role. 1,3 Other factors may include subcutaneous (SC) edema and fibrogenesis; SC adipose protrusion; and decreased dermal thickness with age. [1][2][3] Several procedures and technologies that target the dermis and adipose tissue, in addition to fibrous septae, have shown improvements in skin texture and the dermal-SC interface; however, these improvements could be secondary to the effects of releasing the fibrous septae.…”