Gluteal ligamentous anatomy and its implication in safe buttock augmentation

Background: The number of buttock augmentations with fat transfer is steadily increasing, but a number of fatalities caused as a direct result of gluteal fat grafting have been reported. The technical details relating to cannula size, injection angle or trajectory, and plane of injection are critical for avoiding morbidity and mortality. However, the ligamentous anatomy has not been thoroughly explored, particularly how the ligaments are encountered in the clinical setting of fat transfer by means of cannulas. Methods: The gluteal regions of five fresh cadavers were dissected, for a total of 10 hemidissections. All pertinent cutaneous ligaments in the region were identified. In addition, cannulas were used to simulate typical variations in injection planes. Results: The osseocutaneous and fasciocutaneous ligaments of the buttocks were identified. Conclusions: The authors describe important ligamentous structures consistently found in the region in cadaveric dissections and discuss the implications while safely performing gluteal augmentation. The anatomical features, boundaries, and soft-tissue attachment points may play a role in cannula-directed fat injection misguidance. The ligaments, when not released, can lead to undesired deep injection and therefore fat lobule migration into the venous system. The density, danger zones, and soft-tissue attachments must be clarified further as we continue to offer our patients improved buttock contour with a higher safety profile.