Back or buttock dimples, often called the Dimples of Venus, are believed by some to be a mark of beauty. (Venus = Roman goddess of beauty) They are bilateral skin indentations on the lower back just superior and lateral to the top of the intergluteal cleft. Some people have these lower back dimples while others do not. It is a genetic feature which can be inherited.
Anatomically they relate to the sacroiliac joints and are created by the ligaments which stretch between the posterior superior iliac spines and the skin. In spine surgery they are known as the lateral lumbar indentations which serve as landmarks for finding the superior articular facets of the sacrum as a guide to placing sacral pedicle screws.
For those who seek to have them, they may or may not be attainable. Lower back strengthening exercises are purported to create them but I have no direct evidence that this is true. While the lower back can certainly be strengthened, it is not clear how that would create indentations over the sacroiliac joints unless one already has a hint of them.
The only way to create lower back dimples is to selectively remove any subcutaneous fat between the skin and the underlying fascia of the sacroiliac joints. Injectable options do exist and could be attempted by one of two compounds. High dose steroid injections (Kenalog 40) is well know cause fat atrophy but may thin the overlying skin as well. Deoxycholic acid injections (Kybella) are more selective for dissolving fat without affecting the overlying skin. It would likely need more than one injection session to be optimally effective.
So called Dimple of venus surgery is fat removal limited to the desired dimple area. To be successful one had to have some subcutaneous fat to remove. Small or microcannula liposuction done under local anesthesia is one surgical option. Another approach is to make a small vertical incision and directly excise fat and sew the dermal skin edges down to the fascia with a single buried suture.
Dr. Barry Eppley