Jose G. Veliz, M.D. M.S.A.
Medical Director
Palomar Pain Management Center
Pomerado Pain Management Center

One of the most common, but underdiagnosed, causes of back pain is a painful sacroiliac joint.  The term used to describe this is Sacroiliac Joint Dysfunction.  In fact, in my practice, a lot of patients are referred to me for spinal injections when, in fact, the cause of their low back pain is Sacroiliac Joint Dysfunction.  I have even seen patients who were told they needed back surgery when the cause of the pain actually emanated from their sacroiliac joint.  For this reason, I like to refer to Sacroiliac Joint Dysfunction as a master of disguise.  

The sacroiliac joint is located between the sacrum and the iliac bone.  From the outside, these two joints can be seen as two small dimples on each side of the low back at approximately the level of the belt line.  Compared to other joints in the body, there is very little motion.  This is because the sacroiliac joints are held by several very strong ligaments.  One exception to this is near the end of pregnancy, close to delivery, when hormones are produced which cause the sacroiliac joints to relax.   For this reason, it is very common for pregnant women to develop Sacroiliac Joint Dysfunction near the end of pregnancy or even after delivery. 

When the source of pain emanates from the sacroiliac joint, pain can occur in the low back, buttock, hip, groin and leg – usually not below the calf.  For example, it is not uncommon for a right sacroiliac joint dysfunction to result in right sided low back pain, right buttock pain, right hip pain, right groin pain and right thigh pain.

There are many causes of Sacroiliac Joint Dysfunction.  Some of these may include trauma, differences in leg length, pregnancy, altered gait patterns, arthritis, and infection.

Sacroiliac Joint Dysfunction is diagnosed by history and physical examination.  This is why it is a good idea to write down your symptoms before going to visit your physician.  You will then be prepared during your appointment with the doctor. 

There are certain physical examination maneuvers which will make it more likely that Sacroiliac Joint Dysfunction may be the cause of your back pain.  The doctor may also choose to order diagnostic injections of the sacroiliac joints to confirm that this is the source of your pain.  These diagnostic injections into the sacroiliac joints must be done with x-ray guidance.  If not, there is a good possibility that the needle will be misplaced.  Other treatments include physical therapy, sacroiliac joint braces, orthotics, radiofrequency and chiropractic or osteopathic manipulation.  Acetaminophen, “Tylenol” or non-steroidal anti-inflammatory medications “Aleve, Ibuprofen, Motrin” etcetera may also be used.  Be sure to review the dosages with your physician.  On rare occasions, patients suffering with intractable pain may be candidates for fusion of the sacroiliac joints. What is surprising is that patients who have Sacroiliac Joint Dysfunction will frequently have x-rays and MRIs which appear to be normal.

It is interesting that Sacroiliac Joint Dysfunction was first described in 1905, by Drs. Goldthwaite and Osgood, as a source of low back pain.  In fact, over the next three decades, Sacroiliac Joint Dysfunction was considered the primary cause of low back pain.  Then, in 1934, Drs. Mixter and Barr, published their discovery of slipped discs in the lumbar spine.  This led to the sacroiliac joint being all but forgotten as an important source of low back pain.

Sources are:   The Adult Spine: Principles and Practice, 2nd Edition, 1997, pp 2343 to 2363.
Walker, J., The Sacroiliac Joint: A Critical Review.
Phys Ther, 1992; 12:903-916.