SI Joint Fusion? The Most Unnecessary Spine Surgery?

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Several years ago I began to see a very disturbing trend. Pain management physicians fusing SI joints. While we were supposed to be the good guys who offered patients non-surgical options, instead we were now just another specialty where invasive surgery could be monetized. SI joint fusion is a great example of this slippery slope. Let’s dig in.

The Slippery Slope

This CT Scan of the pelvis and SI joints was posted on Linkedin. On the right of an image, the bright white is an SI joint fusion device. On the left, you see a device (looks like a bullet) that has missed the SI joint and ended up in the abdomen. Is that a good thing? Nope, it’s a disaster.

When first I saw this image I and several other physicians were appalled. Why? SI joint instability, which is what this SI joint fusion procedure was supposed to treat, can be treated easily with orthobiologic injections using platelets or stem cells. That’s a procedure where bullet-shaped metal objects don’t end up in the abdomen. How did we get here?

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The Birth of Interventional Pain Management

Way back in the early 90s, a new concept was born. Patients that had herniated discs causing sciatica could skip surgery and end up instead getting an x-ray guided epidural steroid injection. This was revolutionary at the time and was the birth of a new medical specialty called interventional pain management.

Through the years the specialty added many more procedures like facet joint injections, medial branch blocks, and radiofrequency ablation. Hence, it sort of became the “anti-surgery” specialty. Meaning that Interventional Pain Management physicians (IPM) offered patients an option outside of spine surgery.

The Birth of Interventional Orthopedics

While IPM was revolutionary, it has a problem. It’s destructive. Meaning the steroids used as anti-inflammatories to help pain also destroyed tissue. The radiofrequency energy used to ablate nerves and temporarily help pain destroyed those nerves and the critical muscles which they supplied.

As a pain management physician, this is where I found myself 15 years ago. Happy that I had non-surgical treatments to offer patients, but generally dissatisfied with the options, few of which helped anyone longterm. Hence, in 2005 I began to use platelets and bone marrow concntrate in my patients and never looked back. For the first time, I had solutions rather than temporary pain-relieving procedures.

Treating SI Joint Instability with the Healing Agents from the Patients Own Body

The SI joint lives between the tailbone and the pelvis and is responsible for acting as a shock absorber for forces coming up from the legs to the spine. It doesn’t move like a knee or a hip, it just gives a little here or there. It’s held together by strong ligaments that can become stretched during pregnancy, trauma, or wear and tear. When that happens, the joint becomes unstable. That instability can lead to arthritis in the joint and pain. That’s what the fusion device above, the one that ended up in the abdomen, was supposed to treat.

Treating an unstable SI joint without resorting to surgery is very easy. In fact, it’s got such a high success rate with simple things like prolotherapy that it’s almost a sure thing. The patients that fail that treatment usually respond to platelet-rich plasma (PRP). Finally, the rare patients that fail PRP usually respond to bone marrow concentrate. Based on that experience, it’s only a few percent of these patients that fail all of the less invasive injection therapies above who should ever be considered a candidate for SI joint fusion. However, that’s not what’s being done.

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The SI Joint Fusion Bonanza

To review, SI joint instability is a problem where a high percentage of patients can be easily fixed with a few simple interventional orthopedic  injections. That’s not just my opinion, but we have randomized controlled trials that back that up (1,2). Hence, this stuff works.

While that might seem like a great thing, that’s a real problem for the SI joint fusion industry. Why? That decreases the number of patients who need these expensive pieces of hardware.

What Exactly Is SI Joint Fusion?

SI joint fusion involves banging one or more metal dowels through the joint to fuse it so it can’t move. Given that the joint is a natural shock absorber, it’s no longer absorbing shock after that procedure and the fusion destroys the joint itself. Meaning that once you get this procedure, there is no going back.

What Are the Possible Complications?

At the most common sense level, you’re banging a large screw or dowel into the SI joint, which destroys the cartilage in the joint. In addition, as you see above, these screws can also go astray. This is the comparison between what’s inserted in an SI joint fusion and what’s used in an inteerventional orthopedic injection:

si bone ifuse procedure

The research often cited by the manufacturers of these devices often states that only about 5% of the patients have significant complications, but is that really accurate? A different research study that was wasn’t paid for by the device manufacturers disputes those numbers [5]. This data was derived from health insurance claims on the reported complications from more than 400 SI joint fusion procedures. The rate of bad outcomes was three times higher (4.7% vs. 16.4%)!

In addition, more than 500 complications for one of these devices (SI Bone) are documented in an FDA database. Here’s that data broken down by complication:

SI bone Ifuse device

When I perform a word search on those reported complications, this is what I get:

Si bone

Are SI Joint Fusion Patients Getting these Less Invasive Options?

As you can see, these are invasive procedures with lots of serious complications. Despite that, there has been an explosion in the number of companies offering these devices and teaching doctors how to bang them into SI joints. For example, there are now some 25 SI joint fusion implants on the market. These have names like iFuse (SI Bone), Entasis (CoreLink), SImmetry (RTI Surgical), SiCure, SImpact, Life Spine, TrriCor (Zimmer Biomet), Silex, Sambascrew, Orthofix, SI-LOK, SIFIX (Nutech), SiJoin (VG Innovations), Prolix SI fusion system, SI-DESIS, RIALTO™ SI Fusion System (Medtronic), and SacroFuse (SpineFrontier).

So let’s think about the math here. SI joint pain is known to afflict about 1 in 4 patients with chronic back pain (3). Few of these patients have a problem that can’t be solved through physical therapy or a single steroid shot. That leaves a relatively small number of patients with chronic SI joint instability who need something else. If we further reduce that number of patients by the high percentage that will respond to interventional orthopedic injections, that doesn’t leave nearly enough patients for 25 companies who make SI joint fusion devices.

For example, 40,000 SI Bone procedures were done as of 2019 (4). That’s a whole lot of complications. As shown above, we know of at least 500 complications that were reported to the FDA. Based on my experience, for every one complication where the doctor takes the time to report it, many will go unreported.

My Experience

What I see on the ground is that an increasing number of patients who would normally respond to interventional orthopedic injections using the healing agents from their own body, are now getting a much more invasive SI joint fusion. Why? SI joint fusion is a great business plan. A metal dowel made for 10 bucks in China can fetch a thousand dollars plus. The doctor is also paid big bucks to perform the procedure by the insurance company.

Why Are We Doing This to Patients?

Why are we taking patients who could be easily treated with that needle above and banging huge metal dowels through their joint? For the pain management physicians performing this procedure without performing any orthobiologic injections, I challenge the medical wisdom of exposing these patients to significant additional risk. We can do better and these physicians know it.

The upshot? SI joint instability is easily fixed through injections. In the vast majority of these patients, we don’t need to bang metal pieces through their joint that may end up in their abdomen! Hence, it’s time to put patient safety before device company profits.



(1) Singla V, Batra YK, Bharti N, Goni VG, Marwaha N. Steroid vs. Platelet-Rich Plasma in Ultrasound-Guided Sacroiliac Joint Injection for Chronic Low Back Pain. Pain Pract. 2017 Jul;17(6):782-791. doi: 10.1111/papr.12526.

(2) Kim WM, Lee HG, Jeong CW, Kim CM, Yoon MH. A randomized controlled trial of intra-articular prolotherapy versus steroid injection for sacroiliac joint pain. J Altern Complement Med. 2010 Dec;16(12):1285-90. doi: 10.1089/acm.2010.0031.

(3) Simopoulos TT, Manchikanti L, Singh V, et al. A systematic evaluation of prevalence and diagnostic accuracy of sacroiliac joint interventions. Pain Physician. 2012;15(3):E305-E344.


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