Surgery for Chronic Sacroiliac Joint Pain: What We Know and What We Don’t Know!



Chronic pain from the sacroiliac joint (SIJ) has been discussed in the surgical literature for almost a century by orthopedic surgeons, and more recently neurosurgeons, with hundreds of papers describing ways to address this now very well accepted pain generator.  In the U.S. from a surgical perspective we have gone from a few hundred SIJ fusion surgeries a year for this pain generator to now tens of thousands annually in just over one decade.  Starting with one company in 2008 manufacturing devices that were dedicated to fusing the SIJ there are today 24 companies doing the same.  Becker’s Orthopedic Spine Review is postulating that at least 50,000 of these fusions will be performed annually in America by 2020. Logic would suggest that we as a group of educated surgeons must have learned a lot of new information about pain in this joint and how to fuse it during the past ten years based on this exponential increase in the rate of SIJ fusions being performed and the numbers of medical device manufacturers jumping “head-long” into the fray.

What do we really know and what have we learned in the last decade about chronic pain in the SIJ and performing fusion surgery for it?

The following is what I think we know to be true:

  1. Pain coming from the SIJ can be severe and disabling (e.g. many women having had children by vaginal delivery describe the pain as worse than what they experienced in child birth).
  2. Up to 22% of all new low back pain has the SIJ as one of or the primary pain generator (multiple valid references in peer reviewed literature).
  3. Range of motion for the SIJ in any of its movements tested is <2 degrees (most suggest <1 degree).  These are results from numerous cadaver studies over time.
  4. There is a high sensitivity and an uncertain specificity with all the current diagnostic tests for SIJ pain for both noninvasive and invasive technics.
  5. Thrust manipulations of a “painful SIJ” frequently provide at least temporary relief from pain.
  6. At least 75% of the time after the SIJ is surgically stabilized, so that residual movement is at least less than original movement, pain will be relieved earlier rather than later.
  7. A solid fusion by measure of X-Ray or CT scan has not been proven to correlate with pain relief.
  8. If hardware becomes loose the pain can be expected to return, and if restabilized can be expected to diminish.
  9. Hardware, if not covered with fascia or muscle, can become painful and lead to revision surgery.
  10. If the lumbosacral spine is fused or rigidly stabilized the stresses on the SIJs increase.
  11. The complication rate for a lateral minimally invasive surgical stabilization/fusion is between 1-17% with a significant revision rate in this group.

The following is what I think we don’t know:

  1. Where the source of SIJ pain is (e.g. from the joint itself, the ligamentous structures surrounding the joint, a combination of both).
  2. why a chronically painful SIJ frequently causes sciatica.
  3. How to unequivocally diagnose a chronically painful SIJ.
  4. What the true function of the SIJ is in homo sapiens.
  5. If any one of the various movements or rotations (e.g. flexion, extension, rotation, nutation, or counternutation) of the SIJ are responsible for causing more or less pain than the others.
  6. The finite stress analysis of the SIJ(s). Why this might be important information when considering fusing the joint and where devices might be most effective in achieving fusion and decreasing pain.
  7. Why the “thrusting manipulation” maneuvers to the painful SIJ frequently decrease pain, at least temporarily.
  8. Why just stabilizing the SIJ, even when some motion might persist and/or a solid fusion does not form, there is pain relief more often than not.
  9. The appropriate clinical mechanism through which a patient is selected for SIJ fusion surgery.
  10. How different pathologies affect SIJ pain generators (e.g. is the pain generated from an SIJ due to inflammatory arthritis different than from osteoarthritis?), and surgical results.
  11. What type of surgery is the most appropriate for fusing the SIJ in a specific patient.
  12. What should be standard salvage procedures for failed SIJ fusion surgeries based on science and logic.
  13. How fusions of one or both SIJs affect resultant stresses on adjacent joints, and if these stresses are clinically significant, especially long-term.
  14. How many patients, currently being treated by ongoing manipulations or injections despite short-term improvements, are not being cured from their chronic pain. I call this the “revolving door” of conservative treatment and estimate that there are tens of thousands of individuals in this category.
  15. How a patient should be treated when surgical pain generators are present in both the spine and the SIJ(s) at the same time.
  16. How to best train surgeons and assure their proficiency in providing the best care and treatment to patients with chronic pain from dysfunctional SIJs.

What have we learnedduring the past decade about treating chronic disabling SIJ pain after performing tens of thousands of fusion surgeries on these patients? After scrutinizing the above, not much! 

There is no question that each of these lists is incomplete, but the main purpose for sharing these is to make the following concrete statements why we don’t have more answers than we do:

  1. Surgeons are not being trained to understand chronic SIJ pain as being responsible for more than one fifth of all the causes for low back pain.
  2. Not only are surgeons not being taught, but they also are not being tested on their proficiency in treating patients with this type of chronic pain.
  3. The average orthopedic and neurosurgeon does not look for a SIJ source of pain during their initial examination of new low back pain patients.
  4. Industry is the major driver in all of the tens of thousands of SIJ fusions performed each year in terms of educating surgeons and soliciting patients for surgery.
  5. Industry makes their own rules regarding the SIJ and educating both surgeons and the public with one goal in mind; to increase profits.
  6. In America concerning fusion surgery for the SIJ there is no oversight by organizations or government agencies for poor surgical patient outcomes from surgeons, hospitals, and industry.  The only accountability they endure is that of individual patients and their families.
  7. There are no current concerted efforts to answer any of the 16 items I listed above as what we don’t know, by the large surgical educational societies, the government (including the FDA), and the American Board of Medical Examiners.
  8. This all means that we as a society are dealing with tens of thousands of SIJ fusion surgeries each year not knowing if we are operating on the right patients and performing the best surgery for each patient’s unique pathology.  We also do not know the true complication rates from these surgeries and the overall morbidities they do cause.

We really do need major paradigm changes in the way chronic SIJ pain is handled by professionals in America in order to protect patients and give them the best surgery possible when all conservative measures fail.

Getting our large surgical educational societies to claim chronic SIJ pain as a major problem, set about encouraging research on this joint, and encouraging dialogue from everyone involved would be a good start.

Left the way it is, this entire problem and the surgical treatments for it will remain largely stagnant and undefined with industry continuing to run the show for profit while having no true understanding of this joint or the tens of thousands of patients they are surgically treating.  Truly, without change we are “stuck in the mud” and without exploration the SIJ world will remain “flat”.

Bruce E Dall, MD



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