My Letter About How SI Joint Fusion Likely Won’t Help Patients in the Long Run

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SI joint fusion

I’ve blogged a few times about why I think the new “minimally invasive” SI joint fusion is not a good treatment option. After that I was asked by a professional organization in Oregon to write a letter explaining my views to their Health Evidence Review Commission, which is considering coverage for the device. This is that letter:

Ariel Smits, MD MPH

Medical Director, Health Evidence Review Commission

RE: “Minimally Invasive Sacroiliac Joint Fusion.”

Dear Dr. Smits

It’s my understanding that your Value-based Benefits Subcommittee is reviewing the data on whether to support reimbursement for minimally invasive sacroiliac joint (SIJ). This is a procedure that I see causing immense, long-term potential harm to patients. Let me explain.

The SI or Sacroiliac Joint

The SI joint resides between the sacrum and ilium—hence the name sacroiliac. The joint has movement, but not like a traditional hinge joint. It’s viscoelastic and “gives” in specific directions and acts as an important shock absorber between the legs and the spine [1]. Basically, it helps transmit energy from the feet to the spine and vice versa.

The joint is ear shaped and is surrounded by strong ligaments that dictate movement. The deep abdominal muscles also assist in stabilizing the joint [1]. The SI joint can be injured by a fall on the buttocks, a car crash, or through other mechanisms [1]. Pain from the SI joint generally localizes on the side of the sacrum at the PSIS. However, symptoms can also mimic radiculopathy, refer into the groin, or to the side of the hip [1, 2]. Physical therapy and chiropractic are common treatments and when those fail, the next most common recommendation is to inject corticosteroids into the joint [3].

Fusing Spinal Joints

I’ve treated patients with post fusion pain and problems my entire career. It’s often personally upsetting to see the walking wounded these procedures produce. As a result of treating hundreds of such surgically disabled patients through the years, I often tell my patients that fusion is a “dog with big fleas.” What do I mean?

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 magnified forces.

As an example of how early data on invasive procedures can deceive, spinal fusion for stenosis is important to highlight. Many case series and comparison trials through the years had suggested that lumbar fusion for lumbar stenosis was effective [4]. However, a recent randomized controlled trial showed no efficacy and much higher complications over laminectomy alone [5]. This is consistent with the experience of many clinicians. So while the lower-level research shows promising results, higher-level research shows no efficacy amidst additional patient harm.

For the SI joint, the joint below is the hip, and the joint above is the L5–S1 spinal segment. As discussed, the SI joint is a key energy transfer mechanism, so fusion eliminates that important shock absorber. The hip joint and lower lumbar spine are the next levels that will be overloaded once the SI joint no longer moves.

The Research Supporting Minimally Invasive SI Fusion

Two new studies have now been published which are one and two year follow-ups of patients that were previously enrolled in a randomized controlled trial (RCT) with a 6-month follow-up [6, 7]. Before I review those, let’s examine the results from the first 6-month RCT [8].

The 6-month study was sponsored by the company that makes the extraordinarily expensive hardware to fuse the SI joint. The study seems to show much better results for the SI joint fusion treated group than those patients who were randomized to be treated with physical therapy and SI joint injections. However, the biggest issue with the study is obvious. ASD doesn’t generally show up for several years, so a 6-month RCT doesn’t tell us much.

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 only received nonsurgical care; e.g., physical therapy, steroid injections, etc.). So these new studies are not high-level research. 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 anesthetic block. However, how good is debatable. For example, before the procedure 76% of the patients needed to take narcotics for SI joint pain, and two years after the procedure, 55% were still taking narcotics. Given the significant morbidity caused by long-term narcotic use, reducing that use by merely 21% with more than half of the treated patients still opioid dependent is a significant problem.

The study reports about 5% of the patients had serious side effects, but is that number accurate? Another new study, not sponsored by the manufacturer, refutes that data [9]. The new study was 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%) [9]! The insurance study reports that a significant number of patients are reporting new spinal problems (i.e., the fleas) after the surgery.

Financial Bias

A search of the nonprofit ProPublica website (see shows that the lead author of the new two-year study was paid $72,007 by IFuse Implant, the maker of the SI fusion device under review before the state of Oregon. The second author was paid $34,296 by the company. Interestingly, the full text copy of the two-year paper doesn’t disclose if either of these lead authors owns any stock, stock options, or other equity in the company.

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 nonsurgical. 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 device that can garner huge insurance reimbursement), there has never been the funds needed to get this simple treatment approved by insurance companies.

Prolotherapy treatment for the SI joint would involve injecting the loose ligaments that are causing instability with the goal being to tighten those, rather than fusing the joint. The interesting thing here is that there already is a randomized controlled trial comparing prolotherapy to a steroid injection of the SI joint showing similar and/or superior results to the studies paid for by the SI joint fusion device company [10]. 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. The prolotherapy study demonstrated stark superiority over the steroid injection. The cost? A few hundred dollars an injection, a small fraction of the money that will be paid by the State of Oregon for the expensive SI joint fusion implant, surgeon’s fees, surgery center or hospital fees, anesthesia, and complications generated by same.

In conclusion, by the state of Oregon approving compensation for this procedure, I fear that thousands of Oregonians will be needlessly harmed. In addition, cheap therapies that have the same evidence base as this procedure and have none of the side effects of fusing the SI joint are already widely available; hence, there is no need to approve compensation for this invasive and expensive procedure.

Christopher J. Centeno, M.D.


  1. Richard L. DonTigny, B., PT, Dysfunction of the Sacroiliac Joint and Its Treatment. The Journal of Orthopaedic and Sports Physical Therapy, 1979. 1(1): p. 13.
  2. Slipman, C.W., et al., Sacroiliac joint pain referral zones. Arch Phys Med Rehabil, 2000. 81(3): p. 334-8.
  3. Laslett, M., Evidence-based diagnosis and treatment of the painful sacroiliac joint. J Man Manip Ther, 2008. 16(3): p. 142-52.
  4. Weinstein, J.N., et al., Surgical versus nonoperative treatment for lumbar spinal stenosis four-year results of the Spine Patient Outcomes Research Trial. Spine (Phila Pa 1976), 2010. 35(14): p. 1329-38.
  5. Forsth, P., et al., A Randomized, Controlled Trial of Fusion Surgery for Lumbar Spinal Stenosis. N Engl J Med, 2016. 374(15): p. 1413-23.
  6. Duhon, B.S., et al., Triangular Titanium Implants for Minimally Invasive Sacroiliac Joint Fusion: A Prospective Study. Global Spine J, 2016. 6(3): p. 257-69.
  7. Duhon, B.S., et al., Triangular Titanium Implants for Minimally Invasive Sacroiliac Joint Fusion: 2-Year Follow-Up from a Prospective Multicenter Trial. Int J Spine Surg, 2016. 10: p. 13.
  8. Whang, P., et al., Sacroiliac Joint Fusion Using Triangular Titanium Implants vs. Non-Surgical Management: Six-Month Outcomes from a Prospective Randomized Controlled Trial. Int J Spine Surg, 2015. 9: p. 6.
  9. Schoell, K., et al., Postoperative complications in patients undergoing minimally invasive sacroiliac fusion. Spine J, 2016.
  10. Kim, W.M., et al., A randomized controlled trial of intra-articular prolotherapy versus steroid injection for sacroiliac joint pain. J Altern Complement Med, 2010. 16(12): p. 1285-90.”
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14 thoughts on “My Letter About How SI Joint Fusion Likely Won’t Help Patients in the Long Run

  1. Sam

    Briliant! Thanks for sharing.

  2. Pam

    So glad I stumbled upon your article. I had the infuse by Dr Wayne Polly, founder of the devise, at the University of Mn 2/13. Had problems for 20 yrs, 3 auto accidents, 85′, 99′, 2003′. Could not walk by 03′. Carried into emergency room at U. Have been under there care since the 80’s. Convinced me to have framenectomy, nerves like tangled telephone wires, I was told. Had this surgery 2/12. Was good for about a week then the excruciating pain in l low back buttocks and down leg. Over 15 yrs of pt off and on, always heard, so dysfunction. L5, S1. Polly was recommended for SI fusion. Saw Polly, talks a good game. Had fusion 4/13, ruined by life. I was in a care home for 30 days after the procedure. Was very hopeful. I’ve voiced my deep concerns about the intense pain. Dr Polly convinced me it had to do with my piraformis and said I would need this muscle cut to release pressure. 11/13 had piraformis release, cut Thru my glutteous Maximus and piraformis muscle. Today, I can hardly walk. After my repeated visits and stating my dissatisfaction and excrutuating pain, he would X-ray me and tell me everything looks good but that I would most likely in time need my r si joint fused. Nov. 2015 he told me there was nothing else he could do for me. Since then another doctor has pointed out my 34• degree scoliosis, and where I’m arthritic at L5. I’ve been told my sciatic nerve is trapped. Doctor Polly is the teaching spine surgeon at U and never mentioned my scoliosis. Saw a prominent spine surgeon here 1/2016, did not agree w si fusion. Wanted to do a TLIF on my L5 region and proceeded to tell me I would break down in 3-5 yrs above and need another fusion. I backed out. My wonderful chiropractor at Hopkins Health and Wellness stated that the fusion was totally not necessary and pointed out on my MRI how the fusion is pulling causing stress on my L5 region.
    Went to another si called expert, was told nothing was wrong with me. Private practice and now that I’ve lost everything since 2003 and reduced to Medicare I feel no one wants to help me. My primary doc sent me to another surgeon in May 2017, asked if I’ve had cat scan done by U since fusion. They have never given me one. Saw him today after two months wait for results. He told me today, the fusion has never healed, it’s been 4 yrs this past April. I’ve fractured 3 times off the fusion in my pelvis since the fusion, can’t drive or sit for any length of time, can’t stand in one place. I’ve told the doctors for over 3 yrs, I feel like I’m infected in that area, feel broken. I feel treated like I’m a lunatic. I was butchered by them for a notch on their belt. I’m trying to regroup and figure out how to heal. I asked Polly in Jan 2016 to remove hardware, said impossible, Luke concrete in rebar. I get it but I’m dying. States to four docs at u, think I’m allergic to the two implants. Nothing has been done. Contacted 4 attys here, no one wants to touch. These doctors need to be stopped.
    Please advise, your article is very true. They have had the web bought in their favor over the past 4 yrs. to hide the horrendous maiming this procedure is costing and lining their pockets deeply. Having a bilateral facet joint block tomorrow with this new doc who told me fusion has never healed.
    No where to turn. I can’t even walk around the block. I’m 5’5, 113# and led an extremely active life. I’m just looking for someone who believes me.


    1. Regenexx Team Post author

      So sorry to hear all you’ve been through! Sadly though, this is not as unusual as we would all hope. Your situation flags up how crucial the correct diagnosis and the least invasive procedure to correct the problem is, as fusions like other joint replacements, are irreversible. It is an incredibly frustrating experience to deal with a system where the answers are plugged in without regard to the questions! Please see: Unfortunately, stem cell procedures are not covered by any type of insurance yet, neither private nor Medicare.

  3. Kari

    I had an SI joint fusion November 2015 after a year of physical therapy, massage, acupuncture, chiropractic, joint injections, and nerve ablation did little to help with pain. I was told that fusion was my last hope of any relief. The surgeon was extremely confident that this procedure would end the pain that I had suffered with for years. I had the surgery and things seemed to be going pretty well. I had pain from the incision for about a week but after that I did feel markedly better. Then after about 6 weeks I noticed that painful twinge start to return. I went back to the surgeon for a follow up and told him what was going on. He asked if my pain was better than before the surgery and I agreed that it was. Within the next 4 weeks my pain continued to intensify and I went back to the surgeon. The only thing he offered was to do an xray. The xray showed that the rods were placed correctly and he said there was nothing further he could do for me. For the past year and a half I have been back to trying physical therapy, chiropractic, massage, ice, heat, TENS, acupuncture, and epidural blocks. Last month I started treatment at a pain clinic as I am now having issues with my L5-S1 (confirmed through MRI) and bursitis in my hips. Everyday I regret having the SI joint fusion. The only good thing that happened with the surgery is that the doctors office never got it approved through my insurance and they have rejected payment to this day. So, hopefully, the dent in the doctors pocket has caused him some pain and will make him think twice about pushing this worthless procedure.

    1. Regenexx Team Post author


      So sorry to hear this, but it is so typical! SI joint fusion transfers the load the SI joint was designed to take to the hip and lumbar spine which were not designed to take it, so it would be important to see what can be done to treat these issues before they progress further. Please see: If you’d like us to weigh in on your specific case and see if you’re a Candidate for a procedure, please submit the Candidate form so we discuss how we may be able to help.

  4. Amy Green

    But what do you do when prolotherapy and prp fail? I’ve even had placenta cells injected and I am seeing zero improvement in sitting and no pain relief.

    1. Regenexx Team Post author

      For someone with these issues the type of exam to rule out other things and make sure it’s SI joint instability that is causing the problem is very important. Please see: The issue with placenta “stem cells” is that there are no live and viable stem cells in these products – they contain growth factors similar to PRP. Effective Prolotherapy for an SI joint would need contrast and Fluoroscopy imaging guidnance, as would PRP. If the exam concluded stem cells were indicated, the patient’s own live bone marrow stem cells, again with contrast and fluoroscopy imaging guidance would be what would have the potential to help . Please see: and

  5. Glenda Romero

    After reading the testimonials on your website, I have been suffering from the effects of a SI Fusion. I have every pain described in all of the replies. I recently had a spinal fusion on L2 – L5 with 3 surgeries. However, while trying to find why I was in sooo much pain, a doctor decided an SI Fusion would relieve some of my pain. He was aware my L2 was completely ruptured and needed a fusion to my existing L3, L4, and L5 fusion! He knew my pain was related to the L2 but the need to come away with monetary success, he insisted on the SI Fusion. It has been 2 years and my life is ruined because of the unnecessary surgery! My buttocks is still numb, severe pain in right hip and front leg. My legs also feel “disconnected ” and find myself going downhill physically. I have had my renowned spine surgeon do the L2 fusion
    I am still in severe pain. After 6 months and several days and MRI, my spine surgeon has informed me the SI Fusion was never necessary as he had done my L3 and there was nothing indicating my SI needed a surgery
    He has informed me i will have this severe pain from the SI Fusion for the rest of my life! My question, what is your website’s purpose? Is it just information about unnecessary SI Fusions? What r our options? I thought I would get my life back after my 3 lumbar fusions and I do believe I would have been healed but the pain from the unnecessary SI Fusion is my nightmare? I also asked for the removal of the hardware but my spine surgeon has informed me that is not an option. What do I do now? Can u be of any help?

  6. Glenda Romero

    Dr. Centeno, no reply to date. Have you read my testimonial? Nothing to look forward to because SI Fusion ruined my life. What is the purpose of your website? Is it informational only or is there answers and help for all of us who were subjected to a doctor money-maker unnecessary SI FUSION? Please acknowledge receipt of my dilemma. Thank yoi.

    1. Regenexx Team

      Hi Glenda,
      Very sorry to hear of the surgeries you’ve been through. One of the many issues with Fusion is that Fusion leads to more Fusion, and Fusion leads to Adjacent Segment Disease, which thankfully, we can often help with. Please see:
      The Regenexx website has approximately 3,000 pages , 2,726 of which are Blogs of which the “SI Joint Fusion Letter Blog”, is one. The purpose of the Blogs is educational, as an educated patient is an empowered patient.
      We desperately need many more placebo-controlled trials on many common orthopedic surgeries. My guess is that most of them, in the end, will be shown to be ineffective because they conceptualize what’s wrong in the wrong way. Meaning these are 1980s structural procedures that now live in a world where we know that the body is far more complex than it’s structure.
      In order to advise, we’d need more information through a Candidacy review. To do that, please submit the “Am I a Candidate ” form here:, or, call 303 429 6448 to set up an exam.

  7. Karen Bellis

    I had left SI fusion in June 18 . I had a posterior SI ligament injury and the surgery just damaged the ligaments more and was not indicated for this problem . I have got significantly worse since surgery and am in constant pain and bedridden .my advice is steer clear of fusion . I’m not sure the ligament will heal due to fusion

  8. Valerie Page

    About my SI joint fusions….

    My SI joints became more and more painful after 5 years following my lower lumbar fusion surgeries. My surgeon waited to do a bilateral SI joint fusion until I was 14 years post op lumbar fusion surgery. The year leading up to my surgery I wasn’t able to walk and was pushed around in a wheel chair. My pain was so crippling I had to crawl down the stairs to get to my kitchen. Finally my surgeon did my surgery. But, after my surgery I did not improve because my right SI joint fusion did not take. There was no fusion. And, on both my right and left sides I needed a 3rd spacer implant. I am now 7 months post op since my second SI joint fusion surgery. My left side is now pain- free. It feels fantastic. But, my right side feels like it has failed again. I will be seeing my surgeon’s PA the end of the month to report the bad news. Hopefully my doctor will hold it together and put me back on his table to revise my right side’s fusion. It is reasonable for me to believe my right SI joint should feel like my left SI joint. It has to be possible because my left side is perfect. So, everyone on this post do not give up hope. I refuse to give up hope and I have had 20+ spinal surgeries…LOL!!! Maybe I live in a fantasty world but I’d rather keep my chin up and tell myself my right SI joint can feel like my left if it is repaired. Hopefully my surgeon won’t give up on me.

    1. Chris Centeno, MD Post author

      I hope you can find relief. However, as discussed, fusing the SI joint will place more forces on your hips. So please be careful!

  9. Lamb

    I am at a loss, I.definitely regret not having the correct information, prior to knowing or understanding this procedure, or tri-cor unit used as well, quality of life has definitely been effected , and I Hope someone researches and understands the chronic to critically chronic pain , that a person can and will endure , aka..Lamb

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