Sacral dimple – Symptoms and causes – Mayo Clinic

A sacral dimple consists of an indentation, or “pit,” in the skin on the lower back, just above the crease between the buttocks. Causes. A sacral dimple is a congenital condition, meaning it’s present at birth. There are no known causes. Complications. Rarely, sacral dimples are associated with a serious underlying abnormality of the spine or …

https://www.mayoclinic.org/diseases-conditions/sacral-dimple/symptoms-causes/syc-20377353