XCREST II: The X-factor in Iliac Crest Remodeling for Advanced Waist-to-hip Definition.

Abstract

Background: Modern body contouring has evolved toward structural reshaping, with the waist-hip-gluteal unit as a key determinant of body contour aesthetics. The iliac crest is a critical landmark for lower waist contour.

Objectives: To evaluate the aesthetic outcomes, safety, and anatomical contribution of XCREST II, a combined bony and myofascial technique for lower waist contouring.

Methods: A multicenter retrospective cohort study included 480 patients who underwent XCREST II between 2024 and 2026. Patients were categorized into four groups: XCREST II alone (n = 180), XCREST II + gluteal fat grafting (n = 84), XCREST II + RibXcar (n = 132), and XCREST II + RibXcar + gluteal fat grafting (n = 84). All underwent ultrasound-guided iliac crest remodeling with partial gluteus medius detachment. Anthropometric and BODY-Q outcomes were assessed preoperatively and at 12 months.

Results: Four hundred eighty patients were included. Baseline characteristics were comparable, except for longer operative time in combined procedures (p < 0.001). At 12 months, all anthropometric measures improved significantly from baseline across groups (p < 0.001), without intergroup differences. Complications were low; prolonged postoperative pain and iliac crest pain were more frequent in groups including RibXCar (p = 0.020 and p = 0.017, respectively), without chronic pain. BODY-Q scores improved significantly across all domains (p < 0.001), differing only in body image (p = 0.019) and scar assessment (p < 0.001).

Conclusions: XCREST II, a refinement of XCREST incorporating partial gluteus medius detachment, demonstrated favorable 12-month waist contour improvement and high patient satisfaction, with a low complication rate. Outcomes were consistent across subgroups.