The sacroiliac (SI) joint is located in the pelvis, and it connects the iliac bone (pelvis) to the sacrum (the lowest portion of the spine above the tailbone).
This joint transfers forces and weight between the legs and upper body. It is an important component for energy transfer between the torso and legs.
When the doctor asks the patient to point to their pain, they are trying to identify whether the SI joint might be the cause for the pain. Southern California Hip Institute (SCHI), led by board certified orthopedic surgeon Dr. Tigran Garabekyan, provides orthopedic surgery as well as non-surgical treatments to patients in Los Angeles, Century City, CA, and surrounding communities.
SI Joint Anatomy and Function: Does it Move?
A network of muscles and ligaments stabilizes the SI joint, which also restricts motion. The normal SI joint has a small amount of normal motion of around two to four mm movement in any direction. Therefore, it moves only a little.
The SI ligaments in females are less stiff in comparison to males, which enables the mobility necessary for childbirth. Motion, mainly rotation, reduces with aging, and increased motion is related to pregnancy.
SI Joint Shape, Size, and Texture: It’s a Real Joint
The SI joint is a true diarthrodial joint, which means that it is the most common and moveable joint in the body. The articular surfaces are shaped like an ear, containing uneven ridges and depressions. The concave sacral surface of the joint is covered with thick hyaline cartilage, and the convex iliac surface is lined with thin fibrocartilage.
In the upper part of the SI joint, the ilium and sacrum are not in contact but are instead connected with robust posterior, inter-osseous, and anterior ligaments. The lower half of the joint and anterior is a typical synovial joint with hyaline cartilage on the joint surfaces.
The SI joint is an axial joint with an estimated surface of 17.5 square cm. The surface of the joint is smooth in juveniles and becomes uneven over time.
SI Joint Strain, Injury, and Instability
Upon understanding the location of the SI joint and what it is, it is more convenient to comprehend how it can be injured and degenerate over time and lead to low back or spine, leg, pelvic, or buttock pain.
Common Causes of SI Joint Dysfunction and Pain
The injury and mechanical strain to the SI joint are produced by falls on the backside or a combination of vertical compression and rapid rotation (i.e., lifting a heavy object and twisting). These types of injuries can create ligamentous laxity and allow painful abnormal motion, meaning SI joint pain.
SI joint instability can also initiate from lumbar spine surgery, which involves injury to a large part of the ilio-lumbar ligament. SI joint pain can also occur due to leg length discrepancy, gait irregularities, extended, vigorous exercise, traumatic birth, trauma, and long scoliosis fusions to the sacrum.
Painful SI joint arthritis can also initiate from autoimmune diseases, such as juvenile rheumatoid arthritis, ankylosing spondylitis, psoriatic arthritis, Reiter’s Syndrome, and infections including TB, staphylococcus, and gonorrhea.
Board certified orthopedic surgeon Dr. Tigran Garabekyan receives patients from Los Angeles, Century City, CA, and nearby areas for orthopedic surgery and other procedures.
Dr. Tigran Garabekyan is a board certified orthopedic surgeon specializing in hip preservation. To learn more about Southern California Hip Institute or to schedule a consultation, click here to contact us or call:
Century City / Los Angeles: 310.595.1030
Serving patients in Los Angeles, Beverly Hills, Santa Monica, Century City, West Hollywood, North Hollywood Encino, Sherman Oaks, Van Nuys, Burbank, Glendale and other neighboring cities in the greater Los Angeles, California area.
Also visit http://www.drgorthopedics.com/