SI Joint Fusion Results and Review

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SI joint fusion results

This week I’ve been exchanging emails with a surgeon who does SI joint fusions. It’s been interesting as I’ve been seeing more and more advertising by a company pushing expensive, minimally invasive sacroiliac fusion devices. The surgeon didn’t like a post I did while back on the SI joint fusion technology, so I decided to take another look at SI joint fusion results. This will also be a review of SI joint fusion in general.

The SI or Sacroiliac Joint

First, it’s pretty funny that I’m having this back and forth with an orthopedic spine surgeon on SI joint fusion results. When I first began medical practice in the early 90s, orthopedic spine surgeons were adamant that the SI joint didn’t move. I remember many heated conversations with them that the joint also didn’t cause pain. So it’s interesting to see that a joint that didn’t move and couldn’t cause pain is now being fused because it moves and hurts too joint energy transfer

The SI joint lives between the sacrum (tailbone) and ilium (back part of the pelvis) – hence the name sacroiliac. It does move, but not like a traditional joint. It gives in this direction or that and acts as an important shock absorber between the legs and the spine. Basically, it helps transmit energy from the feet to the spine and vice versa.

The joint is ear shaped and is surrounded by tough ligaments that dictate movement. The deep abdominal muscles also help to stabilize it. The SI joint can be injured by a fall on the butt, a car crash, or through other mechanisms. Pain from the SI joint generally localizes on the side of the tailbone toward the top of that structure, near the dimples of Venus (PSIS). However, it can also travel down the leg, into the groin, or to the side of the hip. Physical therapy and chiropractic are common treatments and when those fail, the next most common recommendation is to inject high dose steroids into the joint to treat chronic swelling.

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Fusing the SI Joint

My SI joint fusion results review comes with a disclosure. I’ve treated patients with post fusion pain and problems my entire career. Believe me, it’s often personally upsetting to see the walking wounded these procedures produce. So I often tell my patients that fusion is a dog with big fleas. What do I mean?

Fusing any joint means that you bolt it together because it’s moving too much or is unstable. Joints that are unstable can be painful and get arthritis quicker, so at face value, it would seem that fusing them solid would be a good idea, but that’s not often the case. Don’t get me wrong, these patients typically report they’re better for few months to a few years, but then the fleas begin to bite!

The fleas are called ASD or Adjacent Segment Disease. This means that the joints above and below the fused joint begin to get painful or break down. This is caused by the fact that energy that should be handled by the fused joint gets shunted above and below to joints that are not prepared to handle those forces. So we solve one problem only to cause two new ones! This is American medicine at it’s best.

For the SI joint, the joint below is the hip and the joint above is the L5-S1 spinal segment (or the lowest part of the low back, just above the tailbone). As I said above, the SI joint is a key energy transfer mechanism, so if you fuse it, you lose that important shock absorber. What happens if you remove the shock absorbers from your car? Eventually the wheel mechanisms will be damaged. Your body is no different. The hip joint and lower lumbar spine will likely wear out faster after you remove the SI joint shock absorber.

The Research Supporting Minimally Invasive SI Fusion

My last SI joint fusion results review was about a year ago when a 6 month study seemed to show that the surgery was effective. My comment at that time was that given that most patients get bitten by the ASD fleas months or years later, a 6 month study didn’t say much. However, this was a randomized controlled trial, albeit one that was performed by a surgeon employed by the company that makes the device used to fuse the SI joint.

The new studies (see study 1 and study 2) are one and two year follow-ups of these same patients. It looks like the randomized controlled trial was abandoned at 6 months as the two new studies only report results for the treated group at 12 months and 24 months (meaning there is no longer a comparison to the patients who got physical therapy). So these new studies are fine, but not high level studies. I will review the two year report for ease of discussion.

The two year study again seems to report good results for patients who had on average about 5 years of SI joint pain before the procedure and who were diagnosed via an image guided numbing injection. However, how good is debatable. For example, before the procedure 76% of the patients needed to take narcotics for SI pain and two years after the procedure, 55% were still taking narcotics. That’s still more than half of the patients! The study reports about 5% of the patients had serious side effects, but is that number for real? Another new study, not sponsored by the manufacturer, refutes that data.

The new study is the only one I’m reviewing here today that wasn’t not paid for by the company. In fact, it’s a search of an insurance company database of the claims and complications paid by Humana on more than four hundred SI joint fusion procedures. At 6 months, the complication rate in this study was more than three times higher than that reported in the device company sponsored study (4.7% vs. 16.4%)! In addition, the company sponsored study never mentioned the fleas, nor did it have a way to measure them. The insurance study reports that a significant number of patients are reporting new spinal problems (the fleas) after the surgery. Again, fusion is a dog with fleas!

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Why This is Likely an Unnecessary Surgery

When all you have is a hammer, everything looks like a nail. Meaning that surgeons tend to try to find surgical solutions for problems rather than non-surgical. Chronic SI joint pain is no different. Let me explain.

Prolotherapy (prolo) is a simple regenerative medicine technique that’s been used since the 1940s to treat SI joint pain. Because it has no business model (i.e. a hyper-expensive drug or screw that can garner huge reimbursement), there has never been the big money needed to get this simple treatment approved by insurance companies. As an example, the makers of the SI joint fusion device look like they have already spent many millions on studies, payment to surgeon consultants, and lobbying to get insurers to begin to approve and pay for this device.

Prolotherapy treatment for the SI joint would involve injecting the loose ligaments that caused the problem in the first place with the goal being to tighten those, rather than fusing the joint together so it no longer moves. The interesting thing is that there already is a randomized controlled trial comparing prolotherapy to a steroid injection of the SI joint showing similar results to the studies paid for by the SI joint device company. While it involved fewer patients, it followed patients for much longer in a controlled trial (15 months vs. 6 months) than the SI joint fusion device. Even though this was not the best form of prolotherapy (the authors tried to keep the techniques similar between the steroid and prolo groups so they just injected the prolo solution into the joint rather than into the ligaments), it still showed stark superiority over the steroid injection.

When I began performing prolo injections in these patients more than 25 years ago, I also saw nice results. However, when more advanced regenerative medicine (regen med) options became available like platelet rich plasma and same day stem cell treatments, I moved many patients to those treatments and have never looked back. In addition, as our clinic’s techniques evolved to recognize the different areas that needed to be treated in many of these patients that were outside of the SI joint, our results improved. Suffice it to say that I haven’t seen an SI joint patient in years that I felt needed this surgery. In fact, I only know of one of our patients out of more than 100 primary SI joint pain patients in the last few years who opted for this procedure despite regen med treatment. Hence, while there may be a handful of patients who need the SI joint fusion procedure, they are few and far between. My biggest concern is that the company making this device is aggressively positioning it as a good solution for every patient who doesn’t get better with physical therapy and who responds to a numbing injection. That would be a real tragedy, as I can’t imagine how many new walking wounded we’ll see over the next decade who seemingly did well for a year or two after an SI fusion, only to need a hip replacement or low back fusion because of overloaded joints elsewhere.

The upshot? The SI joint fusion results from the new research are no more compelling than the old research. While there may be patients out there who can’t be treated in any other way, pushing an SI joint fusion for most patients with chronic SI joint pain is not a good idea. However, with the many millions this company is spending on getting insurers to pay for this surgery, I expect we will see a whole new generation of walking wounded. Just remember, once you go down this route, this procedure can’t be undone, your natural SI joint is lost forever. In addition, please research other options such as prolotherapy or newer regen med options such as PRP or stem cells from a provider who routinely and successfully treats SI joint pain and knows the procedural tricks to get the best results.

This blog post provides general information to help the reader better understand regenerative medicine, musculoskeletal health, and related subjects. All content provided in this blog, website, or any linked materials, including text, graphics, images, patient profiles, outcomes, and information, are not intended and should not be considered or used as a substitute for medical advice, diagnosis, or treatment. Please always consult with a professional and certified healthcare provider to discuss if a treatment is right for you.

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35 thoughts on “SI Joint Fusion Results and Review

  1. Freyda Libman

    I had a fusion at L5 S1 for grade one spondylolisthesis last March and have suffered severe SI joint pain since then as well as piriformis pain. Sitting is difficult and painful as well. I am interested in knowing more about prolotherapy for the SI joint. I live in the Chicago area.

    1. Regenexx Team Post author


      That is a very common situation post L5 SI fusion as the associated segments tend to get overloaded. Here is the Chicago location to help with that issue: chicagoarthritis

  2. Judith Jenney

    I am constantly grateful that because I am such a devout chicken I lay in bed for nearly three months waiting to make the arrangement for spinal fusion surgery, just long enough to see enough recovery that it seemed possible to escape that surgery. I did escape and in a few more months my scoliosis was no worse than it had ever been before the mysterious injury (turning on the shower), at times a bit uncomfortable but possible to live with.

    1. Regenexx Team Post author

      Very glad you escaped spinal fusion! You might consider getting your back examined, as there are likely treatable issues that don’t involve surgery: and

  3. Diana Untermeyer

    After a traumatic horse accident, Dr. Centeno’s treatment tightened up my SI joint. I could literally feel it crunching before the injections. Very successful part of my treatment!

    1. Regenexx Team Post author

      Thanks for that great update, I will pass it along to him! So glad that crunching is gone!

  4. Barbara Schwarz

    I have suffered for 7 years with SI Joint dysfunction. The first six were managed with Chiropractor, PT, a few steroid injections and behavior modification (stand up / sit down work station for desk job, watching the way I sat). For the past year I have suffered, taken pain meds and nothing has brought me out of this episode. A surgeon wanted to do an SI joint fusion and I actually cried when I found out my insurance would not pay for this because it is still considered experimental. So back to my research and I found Regennexx. I am excited to say, I was evaluated and approved for PRP therapy. I am getting my injection next Friday Aug. 5th. Now with that said, all tests, MRIs , etc show that the joint is in pretty good shape. I have a picture perfect back and very good physical shape. Do you think PRP will heal my tendons and Ligaments alone? Can I prepare my body in any way and or do anything to help this work? BTW, this all started because I fell on uneven sidewalk, injured my right ankle pretty bad. This caused my stride/gate to be off and within 5 months after my ankle injury, my SI joint battle began.

    1. Regenexx Team Post author

      All of the management strategies were great except for the steroid shots, which escalates the situation long term because it is so damaging to tissues. The Regenexx Advanced Stem Cell Support Formula is very helpful pre and post treatment as we put a year’s worth of research into determining what combination of ingredients best supports stem cells , whether they’re being injected, or the local stem cells in the joint, and chondrogenesis. To prep for procedure, a low carb diet, avoid NSAIDS, avoid steroids, and don’t take any medication, prescription or otherwise, and don’t eat anything the morning of the blood draw. But do hydrate thoroughly! We look forward to an update!

  5. Rob Flynn

    Once we get to a point where we can heal degenerating joints with a simple injection, would that not make adjacent segment disease a thing of the past, thereby making spinal fusion a less risky procedure? Options are limited for folks with DDD in their lumbar, artificial disc replacement at L5-S1 seems just as scary as fusion, albeit for different reasons.

    1. Regenexx Team Post author

      Interventional Orthopedics does allow us to place platelets and or stem cells with precise image guided injections to address the ASD. However treating the cause of the instability and avoiding the fusion is the best way to avoid the myriad of biomechanical and nerve consequences. See:

  6. Sadhana Patel

    I am from Malaysia & it appears there is no specialist to treat my SI joint pain & now I think even my hips are affected.

    I believe you have none in singapore too.

    Can you help me connect to anyone near this part of the world please? Why aren’t there specialists here

    1. Regenexx Team Post author

      There is a Regenexx location in India, Taiwan and Australia. Please see:

  7. Toni

    Hi! My name is Toni and with a heavy heart I have to admit I did a stupid thing and had my S1 L5 fused. Stupid stupid idea!! Now I stuffer horrible crippling SI joint pain. I do not ever want another surgery. Duh! They don’t work. I live in Canada. Ontario. I am planning to get injection but quiet nervous. Where can I get stem cell injection. I just cannot believe the pain!! Just unbearable!

    1. Regenexx Team Post author

      Unfortunately we don’t know of anywhere in Canada. Knowing how to treat Adjacent Segment Disease by injection is a very specific skill requiring a very high level of training. If you would like to see if you would be a good Candidate for a Regenexx procedure, please submit the candidate form to the right of the blog so you can upload a recent MRI, and our staff can assist in finding the best location for your specific needs. Please see:

  8. Vivien Zapf

    After two pregnancies was in and out of wheelchairs for 2 years with no improvement. I had iFuse surgery and now I can walk, run, and hike for exercise. I’m not at 100% and I have to carefully manage my activity level. However being able to walk and be independent vs. being in a wheelchair is a completely life-changing improvement. The surgery does work for some of us. I agree with you that it is at risk of being oversold, and that some people do have complications, or unreasonable expectations of their pain levels after surgery. I hear about people saying ‘I can only run 1 mile now instead of 10. I need the surgery’. These patients are the wrong candidates for the surgery… It is also tricky to diagnose whether the SI joint is even the right pain generator and most doctors don’t spend enough – or barely any – time on the diagnosis. But given that this surgery has gotten me out of a wheelchair, allowed me to keep my daughters and to keep working – I’m sure you can understand that when I read your article I see red.

    1. Regenexx Team Post author

      We do understand – very happy it helped! Any procedure can help an individual patient. What we’re talking about are the statistics on large groups of patients, and in the case of fusion, the incidence of causing more problems than it solves, are unacceptable.

  9. Vivien

    Most studies find that about 80% of patients experience significant improvement from SI joint fixation. That does not qualify as “causing more problems than it solves.” Again I agree with you that the complication rates need to be accurately documented and the experiences of patients with significant complications need to be shared so people can make informed choices. But sorry I’m not following the rest of your math claiming that more people are harmed than healed by this surgery, and I do have a Ph.D. in physics.

    1. Regenexx Team Post author


      This explains more about the studies, and our experience with the “walking wounded” post fusion patients. Please see:

  10. Kristy bennett

    I am 44 and scheduled fir a sI fusion October 23rd. I fell in January 2013. I was originally diagnosed with permanent nerve damage at my tailbone. Physical therapy and chiropractor did not help. My pain management doctor I’ve been seeing since 7/2016 has done 2 nerve ablations. The first one 11/2016, took 6 weeks and resulted in 4 months of pain relief. The second one was performed 6/2017 and I still have pain. I was immediately referred to an orthopedic surgeon. So I am scheduled. I am scared and tired of the pain. I stored my daughter stem cells when she was born 14 years ago. Please help!!!

    1. Regenexx Team Post author

      Sorry to hear you’ve been put through all of that as SI joint instability and dysfunction can often be addressed with simple precise image guided prolotherapy injections. If that doesn’t work platelets generally do. The purpose of nerve ablation is to “kill” the nerve. While there is sometimes pain relief, bigger problems result, as the nerve has important functions in stabilizing the area. Your own platelets or stem cells would likely help, but the only approved use of stored cord blood stem cells is for 2 types of blood cancers for child whose birth they resulted from. If you’d like to see if you’d be a Candidate for handling this differently, please submit the Candidate form. Please see: and and

  11. Helen Winn

    My husband had the i fuse surgery in 2014. Prior to the surgery he was convinced it was his low back. After PT, pain injections, consultations and a neurosurgeon consultation it was determined it was his SI joint. So more therapy unsuccessfully and then the surgery. Since the surgery he had about 6 months that seemed to have provided some relief. Now it is 3 years later and his pain has intensified 70 to 80% worse than it was to begin with prior to the surgery. Prior to the surgery his pain scale was about a 6 or 7 constant pain. Now it is at minimum an 8-9 with unrelenting pain. He is unable to stand or sit comfortably for any length of time. He is unable to function anywhere close to his previous level of function as far as adl’s. He has gone back to an orthopedic who said it was his back. Now he has gone back to the neurosurgeon who says it is related to the i fuse si joint. Please Help. We are at a loss as to what can be done at this point to give him some relief. Can an i fuse surgery be reversed? Treatment options please. Thank you in advance. We are located in Georgia.

    1. Regenexx Team Post author

      Unfortunately, fusion is not reversible. One of the main problems with fusion is the effects it has on adjacent vertebrae. Please see: and and and There is a good chance we can help by treating the ASD and taking the time to determine what else might be going on. Our Atlanta Clinic opens in April, but there are currently 44 other Regenexx locations. If you’d like to see if he would be a Candidate, please let us know, and we will contact you to help you figure out the best way forward.

  12. Malin H, Sweden

    I have Ehlers-Danlos Syndrome, a genetic defect that affects connective tissue throughout the body. This means that most of my joints have an extended range of motion. The SI-joint, in comparison to other joints, is almost entirely held together with connective tissue, and since the connective tissue is affected, I cannot see how stem cell therapy could offer more than temporary relief, because my body will just keep making more defective connective tissue.

    As I understand it, the IFuse implant has been used for a variety of different sacroiliac joint dysfunctions, but there is no evaluation of which groups of patients benefits the most from the Ifuse procedure. Which groups benefits the most is not something the critics of the study discusses either.

    Being one of the few groups for which SI joint fusion is the only option, I am prepared for the limitations the surgery will put on me. Because I have loose joints all over, I will probably still need a wheelchair (as I’ve had to since 2009) but at least I would be able to sit up for more than half an hour without ending up in excruciating pain. Still, it has taken me two and a halv years to be approved for surgery. Why? Because the consensus now is that SI fusion is a bad idea. That it can be the only hope for some groups of patients is apparently irrelevant.

    I’ve been trying to understand why the resistance against iFuse is so strong, but honestly, I still don’t get it. Is it really that difficult to admit that iFuse surgery can be beneficial for some groups of patients, and that it sometimes may be the only viable option? I thought that physicians wanted to help patients and alleviate suffering, but from where I am standing (or rather, lying half slouched in my recliner), it seems like physicians are lining up for or against iFuse, regardless of what might be best for the patient. And that, to be honest, feels like a giant slap in the face.

    I would appreciate if you would reconsider your cathegorical stance against SI joint fusion. Critics like you are making life extremely difficult for patients like me, and I wish more physicians would take a more nuanced view of treatment options for SI joint dysfunction.

    1. Chris Centeno Post author

      Malin, the issue with iFuse is that fusing any joint just causes the next joint down the line to be overloaded and degenerate more quickly. With EDS those effects will be worse, so I wouldn’t recommend iFuse for any EDS patient. My niece has severe disabling EDS and we have never had to suggest a fusion in any joint instead she has been treated with a combo of prolotherapy, PRP, and same day stem cell treatments. iFuse isn’t a solution, but an invasive and expensive treatment that just shunts the forces elsewhere.

      1. Ruchama

        I have EDS too. I will have ifuse done in a few weeks. I have SI/pelvic instability all my live. And it is this instability that is actually causing an overload on other unstable areas as well!
        I know more EDS people who have had the ifuse done. Some with complications (all of them surgical and not because of overload on other areas) But most with good results.
        The key to it’s succes is good guidance. My rehab specialist has lot’s of experience with eds and with ifuse. He will only refer you when you can see and accept your boundaries and rest. This is to avoid problems after ifuse. And his patients have a high succesrate even years after.
        Treating eds with stemcells? It’s the dna that is wrong. So it will only make more wrong collagen. There is no treatment found yet in production of this wrong collagen.

        1. Regenexx Team Post author

          We wish you the very best of luck! All of our experience is completely to the contrary. We have treated SI joint instability and subluxation in EDS patients very successfully without the complications of surgery, which would be worse for EDS patients.

  13. Polly St John Hughes

    I have a chronic SI joint inflammation and hypermobility. I did prolo therapy for over a year and it really did not seem work for me. I have done 6 treatments of prolozone therapy, which helped a little. My lumbar spine I think benefited more from them than my SI joint from these injections. How have your SI joint patients benefited from the plasma injections? What kind of relief did they get? I still have that as an option, but none of this is covered by insurance.
    I clearly will not consider an SI joint fusion after reading your articles – thanks!

    1. Regenexx Team Post author

      Our SI Joint patients have done very well with Platelet procedures. Determining what’s going on in each individual situation, using fluoroscopy guidance, and determining whether prolo, platelet or stem cell injections is appropriate in that case is very important to success. If you’d like us to weigh in on your case, please submit the Candidate form to the right of the Blog.

  14. Traci R Cahill

    Fourteen years ago this April I had suffered an extremely painful tear (best described as the sensation of tearing chicken from the bone) on upper right buttock a bit under the top of the pelvic. After a plethora of tests…MRI’s (one being pelvic/sacral two years after the injury), x-rays, etc, the doctors couldn’t find anything wrong, on films. Finally diagnosed two years after as a Pelvic Disorder w/ Subluxed Innominate (I know, very general). At that time (before any manipulation treatments) when standing, my left leg didn’t even touch the ground due to my whole central core being ‘off’. Since then I have been deemed as disabled. I now at present day see a Chiropractor two times a week (using non traditional Chiropractic manipulations) that helps me ‘lightly’ function. Main culprit of manipulation is focused on my SI joints and surrounding. I had Sacral Protherapy done five times. Three times by one of the best Prolotherapists on the West coast. Prolotherapy results lasted me about six months max and I was told if I wasn’t better then, I will never be. I’ve been reading a lot about the Stem Cell treatments. Questions: This injury is fourteen years old, what are the chances Stem Cell could help? I hear a lot of relation to Prolotherapy when speaking of Stem Cell, is this another six month at best type of therapy? If there is compensation and lack of stability among the other joints/muscles due to a bad SI joint, how would injecting the SI work together with the other joints/muscles (meaning would other areas need Stem Cell as well)? I appreciate your time. I know this was a bit long but after the amount of time I have suffered with this, I’m cautious of anymore treatments, more money and having my hopes diminshed again. Thank you!

    1. Regenexx Team

      Hi Traci,
      We’d need to examine you to answer your questions about your specific case. Generally speaking prolotherapy is the first line of defense in SI joint treatment, however, more severe cases require either PRP or stem cells. Fluoroscopy is needed to confirm the injections are getting into the joint. There are 3 SI joints, 2 in the back and the one in the front which is often neglected in treatment. Please see: To see if you would be a Candidate, please submit the Candidate form here:

  15. Frank Guenther

    How do I find a practitioner in New Jersey?

    1. Regenexx Team

      Hi Frank,
      On the top of the website,, there is the “Regenexx Clinic Finder” Depending on where in New Jersey, you may be closer to the New Jersey or the Philadelphia location.

  16. Darla

    I have had so joint fused over a year and been in crazy pain I just found out it wasn’t fused all the way and a screw in another part of my back is touching a nerve causing pain and numbness any one know what they do for the SI joint that wasn’t fused all the way

  17. Mary Kenning

    I’ve had PRP in the si joint but it’s very expensive. I would try it again if insurance paid for it but as of now it doesn’t. Most of us can’t continuously pay out of pocket for these treatments. I’ve had numerous prolotherapy injections on my neck which didn’t help

    1. Chris Centeno, MD Post author

      Mary, prolotherapy usually helps SI joint instability and is cheaper. So while it may not be right for your neck, it may be for your SI joint. In the meantime, SI fusion is irreversible and will cause other areas to wear out, so bad medical care that’s covered by insurance should NOT supplant cheap medical care that’s not.

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