Aesthetic augmentation of the hips is largely soft tissue-based. The aesthetic hip area is traditionally perceived as variable locations below the iliac crest bone which at some point becomes the lateral thigh. The iliac crest serves as the superior boundary for hip implants and is often where the location is for their placement incisions.
While the vast majority of hip augmentations lie below the bony crest there are patients who desire actual augmentation of this lateral bony hip projection. (just as there are patients who desire its reduction) Augmentation of the iliac crest requires some implant features which are unique to a bone site in which the implant ‘hangs off the side of a cliff’ so to speak….namely bone screw fixation.
The iliac crest by virtue of being the widest part of the pelvis is exposed to frictional and traumatic forces. It is not a stable area for an implant to sit properly despite being on bone. Screwing the implant into place is critical at multiple locations across the arc of its bony coverage. How many screw locations are needed is not completely known or what is the least number of screws that should be used. Five screws would be the maximum and three would be the minimum. Whether one could get by with even two screws may be a possibility but that minimum threshold has not yet been tried.
Because of the angle that the implant sits on the iliac crest screw fixation should involve bicortical bone purchase. If the implant is angled too high screw fixation may only enter the outer cortical bone and continue into the marrow space. But if placed at the proper angle for the implant on the bone the screws should pass through two cortical bone layers.
Dr. Barry Eppley
Indianapolis, Indiana