Many joints are not fused a birth. These include the skull as well. This allows for rapid growth and maturation of the boney skeleton.
The sacrum is composed of 5 fused vertabrae.
sacrum, it's actually five bones that are fused together.
Sacrum, and Coccyx
Sacrum
Sacrum / Lumbar
Sacrum
The pelvis is three bones (ilium, ischium, and pubis) fused together. So is the sacrum which are five vertebrae fused together into one bone. The frontal bone (forehead) begins life as two separate bones that seamlessly fuse together as well.
The pelvis is formed of 3 fused bones: the illium, ishium, and pubis. The sacrum is formed of 5 fused bones. And the coccyx is formed of 2-4 bones.
They are the bones at the bottom of your spine. Often called the tailbone it is the fused section of 3-5 bones below the sacrum.
There are 7 cervical vertebrae, 12 thoracic vertebrae, 5 lumbar vertebrae, the 5 sacral vertebrae fused to form the sacrum, and the 4 coccygeal vertebrae fused to form the coccyx. Depending on the way you count the number of bones, it comes to as few as 26 bones (just the fused sacrum and fused coccyx are counted) or 33 bones (if you count each bone that is fused).
No the bones cannot be surgically fused together. Bones are only fused together during the growth of adolescents
The Ilium, Ischium and Pubis bones are the three main bones of the pelvis that are fused together