The sacrum is a large triangle-shaped vertebra at the lower end of the spine. It is created when the sacral vertebrae S1 – S5 fuse between the ages of 18 and 30. The sacrum forms the pelvis by joining with the hip bones, which gives the spine a strong base of support. At the top, it joins with the lumbar vertebrae to form the lumbosacral joint. At the bottom, it connects with the coccyx retail bone to form the sacrococcygeal joint. It also links with the ileum on the right and left sides to form the sacroiliac joint. The female sacrum is shorter and wider to allow for childbirth.
The sacral bone is very sturdy as it is responsible for supporting the entire weight of the body. Many important muscles that facilitate leg motion originate on the sacral surface. The sacrum also acts as a protective shield, enclosing the nerves of the lower back. Together with the hip bones and coccyx, the sacrum forms the pelvis, which surrounds the bladder, colon, reproductive organs, and rectum.
The sacrum, when healthy, is rarely prone to fractures, except in people who have rheumatoid arthritis or osteoporosis causing bone deterioration. Most sacral problems originate at the junction with the lumbar spine due to the enormous amount of stress the area incurs. The most common ailment is sacroiliac dysfunction, which produces pain in lower back on either the right or left side that can move as far down as the foot or ankle. The pain is frequently due to either too much or too little motion at the sacroiliac joint.
Conservative management is usually the treatment of choice for sacroiliac problems. Medications combined with rest, hot and cold packs, physical therapy, racing, and chiropractic manipulation are all standards of care. In the event these are ineffective, a sacroiliac joint injection can relieve inflammation enough to start therapeutic exercise. Surgery is a final possible option, with sacroiliac fusion as the procedure of choice.
If you have experienced sacral problems and would like to learn about our treatment choices from one of our specialists, please contact our Seguin or New Braunfels offices.