The intramuscular pocket has become the preferred location for buttock implants. As opposed to the historic subfascial location, deeper intramuscular pockets provide better implant soft tissue coverage which lowers almost all of the known buttock implant complications, particularly fluid collections, inferior migration and implant show. But this is not a natural tissue plane like the submuscular pocket for breast implants. It is artificially created by dissecting into the gluteus maximus muscle which traumatizes and disrupts the natural structure of the muscle. As a result some muscle atrophy occurs from the placement of a synthetic implant which now lies inside the thickest part of the muscle.
Muscle atrophy is well known to occur when the intramuscular pocket is too superficial leaving only a thin cover of muscle over the implant. (1cm or less) This creates a devascularizing effect where the overlying thin muscle quickly atrophies and the implant ends up in the subfascial location. But when the implant is more properly placed deeper into the muscle with 2 to 3cm layer over it does the muscle atrophy and, if so, how much. Furthermore is there a protective effect of exercise since so many buttock implant patients are younger.
In the January 2023 issue of the journal Plastic and Reconstructive Surgery an article was published on this topic entitled ‘Long-Term Aesthetic and Functional Evaluation of Intramuscular Gluteoplasty with Implants’. In this clinical study the authors evaluated 22 patients with CT scans and measured the changes in the muscle around the implants over time. (right after surgery, 1 year postop and then years later)
3D volumetric assessment of the gluteus maximum muscle showed that the average muscle atrophy after one year was around 7%. (6.7%) Many years later the muscle atrophy had not changed significantly and still averaged around 7%. (7.5%) Trying to make a connection between implant size with the amount of muscle atrophy showed no correlation. There was an association between physical exercise and the amount of muscle atrophy recovery.
As an aside no patient showed any implant flipping or malposition.
It is not a surprise that muscle atrophy occurs even when implants are well placed inside the dense gluteus maximus muscle. As muscle are not designed to contain an implant inside it this is an unnatural anatomic occurrence. Between the trauma of the surgery and the pressure of the implant some muscle atrophy is to be expected. This paper provides a quantitative assessment of that atrophy which is less than 10% of the total muscle mass. This did not change over time which indicates the atrophy is from the initial surgical implantation and not an ongoing reaction to the implant. Because the muscle is normal the atrophy can be lessened or even reversed by exercise.
Dr. Barry Eppley
World-Renowned Plastic Surgeon