The infragluteal fold: An appraisal by MRI combined with an anatomic study

Purpose The gluteal region is a key element of beauty balance and sexual appearance. However, there is no clear anatomical description of the infragluteal fold, nor any classification exists allowing standardizing treatment of this area in case of jeopardisation. The purpose of this study was to perform an anatomical description of the infragluteal fold (IGF) matching radiological and anatomical findings in describing specifically raise of the fibrous component at the bone level. Methods Six volunteers (three males and three females) underwent an MRI scan (Siemens Aera (R) 1.5 T) of the pelvic region. T1 Vibe Morpho T2, Sag Space 3D, and Millimetric slices were performed in order to obtain a more detailed selection of the gluteal landmark. Trabecular connective tissue of the region was analyzed using Horos (R) ROI (region of interest) segmentation function. Four fresh cadavers (two males, two females, accounting for 8 hemipelvis) were dissected in order to compare the radiological findings. Results The infragluteal fold is a connectival fibrous band extending from the ramus of the ischium (but not involving the ischial tuberosity, for a length of 21 mm +/- 2 and 21 mm +/- 3), the apex of the sacrum (for a length of 13 +/- 2 and 11 mm +/- 2), and the coccyx (for a length of 19 mm +/- 2 and 20 mm +/- 2, all measures referring to volunteers and cadavers, respectively) reaching superficially the dermis of the medial one-third of the cutaneous fold. No significant difference was found between volunteer and cadaver group in MRI measurement of bony origins, or between MRI and cadaveric dissection measurements. Conclusion Knowledge of this structure will define novel surgical techniques in infragluteal fold restoration.