Response to Comments: Minimally Invasive Surgical (MIS) Fusion of the Sacroiliac Joint (SIJ)

On behalf of SI-BONE, Inc., an innovative manufacturer of medical devices used in the treatment of sacropelvic conditions and diseases affecting more than 28,000 Medicare-eligible patients each year, we appreciate the opportunity to comment on the Palmetto GBA draft LCD for Minimally Invasive Surgical (MIS) Fusion of the Sacroiliac Joint (SIJ) DL39025, DA58739. Our comments reinforce the live presentation delivered on August 2 by Dr. Carlton Reckling, MD, SI-BONE Chief Medical Officer, as well as the recommendations for specific criteria that will impact utilization by Medicare beneficiaries.

Overview of Comments – SI-BONE, Inc. (iFuse Implant System)

SI-BONE, Inc. manufactures and distributes a triangular titanium implant (TTI) used in MIS SIJ fixation/fusion procedures, as part of the iFuse Implant System. There have been more than 60,000 iFuse Procedures performed worldwide since 2009. We would like to offer an update and overview of recent trends involving the procedures we believe Palmetto GBA intends to cover via the draft LCD. Also, there is an upcoming CPT code proposal related to this topic that will be on the agenda at the September 2021 AMA CPT Editorial Panel meeting, which would be relevant to Palmetto’s draft.

As professional societies, commercial insurers, health technology assessment firms, and specialty benefits management companies have all been evaluating the evidence for this procedure very closely over the past several years, and have been publishing about it, we thought it might benefit the Palmetto reviewers to learn what they are recommending now, including patient criteria and specific language about procedures they would be willing to cover. Finally, we have some updated literature not already referenced in the Palmetto draft, which we provide as an attached bibliography.

Recent Procedural Trends – MIS SIJ Procedures

Over the past several years, the evidence for MIS SI joint fusion procedures has grown substantially. This has led to more and more evaluators of the evidence recommending support and coverage of the procedure for their organizations each year, often requiring the use of TTIs as part of the conditions for coverage (or support). In 2017, NICE in the UK and the ECRI Institute recommended the procedure, basing their decisions on the evidence available for iFuse patients. Since that time, this trend has continued, with other groups deciding that only the evidence for the iFuse system of triangular implants was sufficient to confer support or coverage. Groups like eviCore (see 611.2), AIM Specialty Health, and Humana have all issued medical policies in support of the procedure, but only with iFuse. Over 35 payors across the US require the use of TTIs (i.e., iFuse). This now includes Anthem, Inc., which most recently decided to archive its internal policy and delegate the topic to AIM Specialty Health, to cover only the triangular titanium implants available via the iFuse Implant System for patients who meet the criteria.

Today, there is nearly universal access to the MIS SI joint fusion procedure for patients meeting criteria established by their health plan (or the organization responsible for their plan’s guidelines). This includes patients covered by commercial insurance, or who are under a government eligibility program. Recently, the NY State workers compensation board recommended treatment guidelines, as well. Importantly, the BCBS Association has published an evidence Opinion 6.01.23 on this topic. For the past 3 years, BCBSA Evidence Street has stated that:

• Evidence for procedures using triangular MIS SI joint fusion implants, currently only the iFuse Implant System, have sufficient evidence to confer a meaningful improvement in net health outcomes. In terms of the evidence for lateral trans-iliac products, iFuse today remains the lion’s share of the entire body of literature. iFuse is the only implant system with Level I evidence collected from multiple randomized, controlled clinical trials.
• Other device types, including cylindrically shaped implants, or other bone allograft-based products used in this MIS procedure, do not have sufficient evidence.

Triangular Titanium Implants (TTIs) – Key Differences

The shape of the implant, in the context of this MIS SIJ fusion procedure, has proven to be extremely important in outcomes-based decision making and utilization management for many payors. The triangle shape itself has shown to resist rotation in situ, which is a common reason why screws sometimes “back out” after being implanted, sometimes requiring revision surgeries. The surface area of each side of the triangle has also proved to be important in promoting long-term fusion and bone-growth. Data on prospectively followed patients now extends to 5 years, with high patient-reported success rates, and with excellent 85% success of fusion from CT scan evidence of bone bridging across the SI joint.

• Outcomes for triangular-shaped implants, i.e. iFuse implants, have been published with long-term outcomes from Level I and II study now available.
• Evidence for cylindrical shaped implants exists, but is lower level evidence- often Level III or IV from case series.

The unique shape of iFuse TTIs, distinct from the approximately 20 to 25 other FDA-cleared implants that are placed via a lateral, trans-iliac surgical approach, is also notable for purposes of the draft Palmetto LCD. This is because all other laterally placed (trans-iliac trajectory) SIJ systems available to US patients are screw-based, or are otherwise cylindrically shaped implants. Generally, laterally placed implants have been available and in broad use since 2010, and were the subject of the AMA CPT Panel’s deliberation when evaluating the temporary and permanent coding for this procedure in 2013 and 2014. The evidence the AMA panel evaluated in 2013 and again in 2014 was primarily based on the iFuse Procedure, a lateral trans-iliac approach to the SI joint.

Overview of LCDs on This Topic

A scan of the other LCDs on this topic reveal some moderate discussion about patient requirements for Medicare beneficiaries. Notably, most Medicare Administrative Contractors do not require a set of specific imaging, or specifies conservative therapies. Instead, they rely on the opinion of the provider as to what is reasonable and necessary care for their beneficiaries. We think Palmetto is doing the right thing by conducting an update on this topic, because so much has changed since a majority of these LCDs and LCAs were first drafted.

Procedural Evolution – Lateral versus Dorsal (Posterior) Placement Procedures

Importantly, the procedure itself has evolved, and there is now a new, emerging MIS SI joint procedure you should be aware of, and probably create coverage language around, too. The AMA will be taking up this topic at the next Panel meeting in September (see Tab 69 of September CPT Panel agenda). The new, emerging procedure I am referring to is the posterior, or dorsal, MIS approach to the SI joint. In this procedure, the implants are placed from a different trajectory and approach than the lateral trans-iliac procedure, and a different part of the joint is accessed. So the implants actually sit in a different aspect of the joint. Often, the products placed dorsally into the SI joint are bone allografts shaped to fit into the joint, or sometimes biomechanical devices that are small enough to fit in between the bones of the ilium and the sacrum. There are a few FDA-cleared devices using in this procedure, but the majority are performed with 361 HCT/P (bone tissue) products, not regulated as devices but being used as if they were devices. I will suffice it to say that we are peripherally aware of these competitive products, but don’t know a lot about them; but as an orthopedic surgeon, I would think there are major questions of patient safety and outcomes with this new procedure and surgical principles for stabilizing or even for fusing the joint; and we are not aware of high level clinical data about these products.

This is a very different procedure from the lateral trans-iliac procedure, like iFuse and the other cylindrical shaped implants that have been on the market since the early 2010s. Rather, over the past 3 or 4 years the market has seen a significant increase in the use of these new, dorsally placed MIS SI joint procedures. They are typically performed in the ASC or outpatient setting, and we also note many of these companies market the procedure to non-surgeon physicians, like pain management or anesthesiologists.

In December, the International Society for the Advancement of Spine Surgery, ISASS, issued updated recommendations on the MIS SI joint fusion procedure. They published a thorough review of all known literature for lateral trans-iliac MIS procedures, as well as the dorsal or posterior MIS procedures. Under Visual Analog Scale and Oswestry Disability Index scoring, patients with lateral trans-iliac procedures are studied under far more studies, higher level in the hierarchy and quality of that evidence, and performed remarkably better. Also in the December update, ISASS formally recommended surgeons report the MIS dorsal/posterior SI joint procedure using an unlisted CPT code. This was because they felt the dorsal procedure was vastly different from the lateral procedure, and that the CPT code 27279 used for MIS SI joint fusion only described the lateral or posterolateral approach. It did NOT describe the dorsal MIS procedure, in their opinion and the opinion of coding experts they reached out to. Since the December issue was published, other coding experts have also stated the new dorsal procedure is not described by either 27279 or by 27280 used for open SI joint fusion procedures.

The American Academy of Professional Coders’ journal, Healthcare Business Monthly, has seen multiple submissions by coding expert authors that agree with ISASS’ recommendations. In early 2020, the AMA CPT Knowledge Base responded to an inquiry about these dorsally placed bone allograft procedures, and they stated the use of CPT 27279 should be centered on the patient vignettes in the code that describe a lateral trans-iliac procedure only.

At the September CPT Panel meeting, the AMA CPT Editorial Panel will review a proposal to create a t-code for the MIS dorsal/posterior procedure. If accepted, the t-code would be effective for procedures as of July 1, 2022 and therefore we think it is critical this draft LCD at least mentions it, so that a place holder for the t-code in the coding section would be possible and would fit with the final LCD on this topic which may be in force for years to come. The ISASS guidelines updated in December 2020 are much newer than the guidelines for MIS SI joint fusion available from the North American Spine Society, or NASS.

NASS versus ISASS Clinical Criteria

The majority of the work-up between NASS and ISASS versions is the same, and both societies are in agreement there should be conservative therapies tried/failed, a thorough physical exam and provocative tests performed while in the office, and that imaging studies should be used to rule-out other diagnoses and confirm the SI joint diagnosis, too. To clarify the points of the diagnostic workup that are more restrictive than necessary, the 2015 NASS guidelines differ from the ISASS criteria on two points:

• Diagnostic SI joint injections
• Therapeutic SI joint injections

The Palmetto draft LCD relies more heavily on the NASS criteria, which are older than the ISASS guidelines (published in December 2020); importantly, the NASS recommendations do not rely on the significant updates to the literature on this topic that have occurred since June 2015. This includes the long-term follow-up of iFuse patients, which the ISASS update agrees makes up most of the high level clinical evidence. Patients treated with iFuse and studied prospectively under long-term follow-up, did not require certain criteria that NASS currently recommends yet still showed remarkable clinical results. If Palmetto adopts the current draft LCD as-is, which is based on the NASS criteria, it may be more restrictive and stringent than is necessary for today’s beneficiaries who are candidates for the procedure, and would benefit from it.

Recommendations for Revisions to the Draft LCD

We support Palmetto’s update on this topic. We believe an LCD based on the latest evidence is important. To align with the latest evidence on this topic, we think the LCD needs further revision, including:

• The draft LCD should only require 1 diagnostic injection, not two. The threshold for pain improvement from the injection should be 50%, not 75%.
• There should NOT be a therapeutic injection requirement; rather, a provider could perform it if desired, but should not necessarily be required to perform it.
• The draft LCD should mention and exclude the dorsal/posterior MIS procedure in this LCD (t-code activity from the AMA CPT Panel should be revealed shortly, as early as the first week in November). This should be distinguished from the MIS lateral trans-iliac procedure.
• To be the most evidence-based LCD, coverage criteria should only apply to laterally placed triangular implants, a distinction that many organizations including BCBSA and now very large national payors like Anthem and Humana have also made, too.

SI-BONE has conducted a literature review and compared the list of references we maintain with the references used in the current draft LCD. Attached we have provided a full bibliography, to supplement the presentation materials we sent to you earlier in July. There are at least 40 more references than were originally included in the draft, ranging from Level I – IV papers on this topic. In total, there are over 90 articles published worldwide on iFuse patients, or otherwise reviewed in peer-reviewed journals. Data includes 10 Level I papers, and 10 Level II papers. No other SIJ device has Level I data. The data all show significant immediate patient improvement for iFuse-treated patients, which is sustained at 5 years post-operative through prospective follow-up and study of patients.

We appreciate your consideration. Thank you for the opportunity to comment on this important topic. Please contact me if you have any questions or require additional information.

Bibliography was provided for review.

Thank you for your comments as well as the citation list. While additional literature was reviewed it was not cited in bibliography unless it was specifically referenced in the document.

Multiple studies and reviews have evaluated the utility of single and dual anesthetic blocks for the diagnosis of SIJ pain. A single SIJ injection of anesthetic, with or without steroid, carries with it a false positive rate of 20-54%. Due to the high false positive rates from a single injection and relatively low prevalence of SIJ pain, true confirmation of SIJ pain requires 50-75% improvement using comparative anesthetic blocks. While many of the studies on SIJ fusion have relied on 50% relief from a single diagnostic block as an indicator for fusion, it is known that relaxing positive anesthetic block criteria from 75% down to 50% will significantly increase the observed prevalence of SIJ pain and increase treatment failures. Reduction of inappropriate surgery is an important concept in patient safety and decision making. The LCD will not be changed and will continue to require dual diagnostic blocks with a 75% threshold.

As to the requirement for therapeutic injection, there was no literature submitted other than the guidelines from IASS. These guidelines are in contrast with those from NASS, which were most recently affirmed in late 2019. Moreover, therapeutic steroid injections into the SIJ, although not part of this policy, are supported by literature as a conservative treatment measure. Reduction of a riskier surgery when a more conservative non-surgical approach will suffice is an important concept in patient safety and decision making. As such, the LCD will not be changed.

This policy does not address the dorsal/posterior approach as the only CPT^® code cited as medically reasonable and necessary is CPT^® 27279. This code only describes lateral placement of implants into the SIJ. A statement clarifying this will be added to the LCD. As to the shape of the implant, the LCD does discuss that the vast majority of the evidence is for triangular shaped implants. However, there is no means to identify any other shape of implant via edit, as the same CPT^® code is utilized for any laterally placed MIS SIJ implant, regardless of shape.