Compliance with the provisions in this LCD may be monitored and addressed
through post payment data analysis and subsequent medical review audits.

**History/Background and/or General Information**

Low back pain (LBP) is highly prevalent in the Medicare population with
reports of 50 to 84% of adults experiencing back pain at some point and is the
highest cause of disability globally. Approximately 15% to 30% of patients
with persistent mechanical LBP below L5 have pain arising from their
sacroiliac joints (SIJ). SIJ dysfunction is common after spinal fusion; and
reported in up to 40% in some studies.1 The SIJ is a complex structure; it is
a diarthrodial joint with matching articulate surfaces between the sacrum and
ilium separated by synovial fluid and surrounded by a fibrous capsule. It is
only a true synovial joint in the anterior portion, due to discontinuity of
the posterior capsule. It serves as the biomechanical mediator between the
spine and the pelvis. The joint is responsible for flexion and extension of
the sacrum with counterrotation of the ileum and there is only a small amount
of movement. The complexity of the joint is in the small degree of movement of
the joint and the functional supporting structures of the joint (mainly the
muscles, fascia and ligamentous connections).  
  
The sacroiliac (SI) joint goes through many changes throughout life. In early
childhood, the surfaces of the joint are smooth and allow gliding motions in
many directions. After puberty, the surface of the ilium becomes rougher and
coated with fibrous plaques that will restrict motion significantly. These
age-related changes will increase in the third and fourth decade and by the
sixth decade motion may become noticeably restricted. By the eighth decade,
plaque will form and erosions will be present.2 The SI joint has variable
joint capacity as the SI joint degenerates with age and has varied from
0.5-2.5 ml.

The exact pattern of innervation of the joint is unclear, but the subchondral
bone, capsule and surrounding ligaments are innervated by spinal nerves with
nociceptor and proprioceptors and therefore can be a source of pain. Pain from
the SIJ complex may arise from the posterior extraarticular elements that are
innervated by the lateral branches of S1-S3 and L5 dorsal ramus or the
anterior complex innervated by spinal nerves, branches of the gluteal and
obturator nerves and lumbosacral trunks known as the intra-articular
elements.1 The spectrum of pain and dysfunction from SIJ pain is variable but
can be debilitating.

In addition to conservative and surgical modalities, interventional procedures
are used for treatment of SIJ pain. This includes SIJ injections and
radiofrequency (RFA) ablation of the SIJ joint. Injections typically are
intra-articular and contain anesthetic and corticosteroids. Ablation relies on
radiofrequency-generated thermal energy to ablate the sensory nerve fibers of
the sacroiliac joint, thereby interrupting nociceptive signals.

The treatment of individuals with spinal disorders, including pain, can be
complex, and it is recommended that all individuals being considered for
interventional spinal procedures undergo a thorough evaluation and be treated
following development of a comprehensive care plan.

**Covered Indications**

**A.** Sacroiliac joint injections (SIJI) will be considered medically
reasonable and necessary when all the following requirements are met:

  1. Moderate to severe low back pain primarily experienced over the anatomical location of the SI joints between the upper level of the iliac crests and the gluteal fold, **AND**
  2. Low back pain duration of at least three (3) months, **AND**
  3. Low back pain below L5 without radiculopathy, **AND**
  4. Clinical findings and/or imaging studies do not suggest any other diagnosed or obvious cause of the lumbosacral pain (such as central spinal stenosis with neurogenic claudication/myelopathy, foraminal stenosis or disc herniation with concordant radicular pain/radiculopathy, infection, tumor, fracture, pseudoarthrosis, or pain related to spinal instrumentation), **AND**
  5. At least three positive findings with provocative maneuvers: FABER, Gaenslen, Thigh Thrust or Posterior Shear, SI Compression, SI Distraction and Yeoman Tests,3,4 **AND**
  6. Low back pain persists despite a minimum of four weeks of conservative therapies.5

**B. Diagnostic Sacroiliac Joint Injections**

Diagnostic SIJI is used to determine if the etiology of pain is from the
sacroiliac joint complex.3

Diagnostic SIJI are considered reasonable and necessary for patients who meet
ALL the following criteria:

  1. The patient must meet the above criteria for Covered Indications for SIJI, **AND**
  2. The SI joint injections must be performed under CT or fluoroscopy image guidance with contrast, except ultrasound guidance may be considered reasonable and necessary when there is a documented contrast allergy or pregnancy, since the accuracy with ultrasound guidance is inferior to fluoroscopic guidance,6 **AND**
  3. SI joint injection are not performed with other musculoskeletal injections in the lumbosacral spine, **AND**
  4. The documentation should show direct causal benefit from the SI joint injection and not from other musculoskeletal injections or treatments, **AND**
  5. The diagnostic SIJI provided a minimum of 75% relief of primary (index) pain with the diagnostic SIJI (a positive diagnostic response is defined as 75% sustained and constant pain relief for the duration of the local anesthetic and 75% sustained and constant pain relief for the duration of the anti-inflammatory steroid) was measured by the SAME pain scale* at baseline. The measurements of pain must be taken pre-injection on the day of the SIJ injection, post-intervention on the day of the injection, and the days following the injection to substantiate and corroborate the pain scores consistent with the pain relief for the duration of the local anesthetic and/or steroid used.

Limitation: No more than two (2) diagnostic joint sessions, unilateral or
bilateral. To clarify, two unilateral sessions, if performed on one side at
one session and on the opposite side at a different session, would meet the
limitation of two (2) diagnostic sessions.

**C. Therapeutic SIJI:**  
Therapeutic SIJI will be considered medically reasonable and necessary for
patients who meet **ALL** the following criteria:

  1. The patient must meet the above criteria of Covered Indications for SIJI, **AND**
  2. The diagnostic SIJI provided a minimum of 75% relief of primary (index) pain with the diagnostic SIJI (a positive diagnostic response is defined as 75% sustained and constant pain relief for the duration of the local anesthetic and 75% sustained and constant pain relief for the duration of the anti-inflammatory steroid) was measured by the SAME pain scale* at baseline. The measurements of pain were taken pre-injection on the day of the diagnostic SIJ injection, post-intervention on the day of the diagnostic injection, and the days following the diagnostic SIJ injection to substantiate and corroborate consistent pain relief for the duration of the local anesthetic and/or steroid used, **AND**
  3. Subsequent therapeutic SIJI are considered medically reasonable and necessary when the subsequent SIJI are provided at the same anatomic site as therapeutic SIJI, **AND** the therapeutic SIJI produced at least consistent 50% pain relief or at least 50% consistent improvement in the ability to perform previously painful movements and activities of daily living (ADLs) for at least three (3) months from the proximate therapeutic SIJI procedure and compared to baseline measurements for ADLS and painful movements or pain relief using the same pain scale* **AND**
  4. The SI joint injections must be performed under CT or fluoroscopy image guidance with contrast, except ultrasound guidance may be considered reasonable and necessary when there is a documented contrast allergy or pregnancy, since the accuracy with ultrasound guidance is inferior to fluoroscopic guidance,6

Limitations: No more than four (4) therapeutic SIJI sessions, unilateral or
bilateral, will be reimbursed per rolling 12 months. To clarify, a therapeutic
SIJI session if performed on one side first and then on the opposite side at a
different session would qualify as two (2) sessions for the limitation of four
(4) therapeutic SIJ sessions per rolling 12 months.

**D. SIJ Denervation (also called Radiofrequency Ablation or RFA)** is not
considered reasonable and necessary.

*Note: The scales used to measure of pain and/or disability must be documented in the medical record. Acceptable scales include but are not limited to: verbal rating scales, Numerical Rating Scale (NRS) and Visual Analog Scale (VAS) for pain assessment, and Pain Disability Assessment Scale (PDAS), Oswestry Disability Index (ODI), Oswestry Low Back Pain Disability Questionnaire (OSW), Quebec Back Pain Disability Scale (QUE), Roland Morris Pain Scale, Back Pain Functional Scale (BPFS), and the PROMIS profile domains to assess function.

**E. Requirements**

  * The SIJI must be performed under CT or fluoroscopy image guidance with contrast, unless the patient has a documented contrast allergy or pregnancy where ultrasound guidance without contrast may be considered.6
  * The SIJ procedure(s) should be performed in conjunction with conservative treatments.7
  * Patient should be part of an ongoing, and be actively participating in a rehabilitation program, home exercise program or functional restoration program.8,9
  * SIJ primary index pain must be measured prior to the injection at the beginning of the session.
  * The post procedure pain level must be measured after the SIJ injection at the conclusion of the session.
  * SIJI may be performed unilateral or bilateral if clinically indicated within the same session.
  * The documentation must have the radiographic films (i.e. fluoroscopy images) of the procedure in at least two (2) views (i.e., the pre and post contrast injection views in the AP and oblique planes) to confirm intraarticular injection of contrast and the treatment agent(s) used.
  * When documenting the percentage of pain relief from the primary (index) pain compared to the post-injection pain levels, it is insufficient to report only a percentage of pain relief and/or a nonspecific statement of the duration of pain relief. The documentation should include a specific assessment of the duration of relief being consistent or inconsistent with the agent used for the injection and the specific dates the measurements were obtained using the SAME pain scale* used at baseline.
  * When documenting the ability to perform previously painful movements and activities of daily living (ADLs) it is insufficient to provide a vague or nonspecific statement regarding the improvement of previously painful movements and activities of daily living (ADLs). The documentation should include a functional assessment to show clinically meaningful improvement with painful movements and ADLs, if this metric is used to justify the efficacy of the SIJI procedure. Providers should use established and measurable goals and objective scales to assess functionality and ADLs measures.

**Limitations**

  1. Injections performed without radiographic image guidance are not considered reasonable and necessary.6
  2. A SIJI involves the use of an anesthetic, corticosteroid, and contrast agent and does not include injections of biologics (e.g., platelet rich plasma, stem cells, amniotic fluid, etc.) and/or any other injectates.
  3. It is not considered medically reasonable and necessary to perform multiple blocks (ESI, sympathetic blocks, facet blocks, trigger point injections, etc.) during the same session as SIJs injections and during the post SIJ injection efficacy assessment period.
  4. Use of Moderate or Deep Sedation, General Anesthesia, and Monitored Anesthesia Care (MAC) is usually unnecessary or rarely indicated for SIJ injections and therefore not considered medically reasonable and necessary.10 Even in patients with a needle phobia and anxiety, typically oral anxiolytics suffice.9
  5. SIJIs to treat non-specific low back pain (LBP), axial spine pain primary above the level of L5, complex regional pain syndrome, widespread diffuse pain, chronic pain syndrome, and pain from neuropathy are considered investigational and therefore are not considered medically reasonable and necessary.
  6. SIJIs used as part of a series of lumbar spine and musculoskeletal injections to treat nonspecific or chronic low back pain is not considered reasonable and necessary.
  7. In patients with implanted electrical devices, (i.e., spinal cord stimulation, peripheral nerve stimulation, cardiac devices, etc.) and intrathecal pump delivery devices, providers should follow manufacturer instructions and extra planning as indicated to ensure safety of the procedure.
  8. Patients with coexisting psychological conditions or depression related illness should be treated and stabilized prior to proceeding with interventional procedures.11 Multidisciplinary biopsychosocial rehabilitation principles should be provided to these patients.
  9. It generally would not be considered medically reasonable and necessary for treatment with SIJIs to extend beyond 12 months. Frequent continuation of SIJIs injections over 12 months may trigger a focused medical review. Use beyond twelve month requires the following: 
    1. Pain is severe enough to cause a significant degree of functional disability or vocational disability and providers use established and measurable goals and objective scales to assess functionality and ADLs measures.
    2. SIJIs provides at least 50% sustained and consistent improvement of pain and/or 50% sustained and consistent objective improvement in function (using same scale as baseline) for at least three (3) months.
    3. Rationale for the continuation of SIJIs including but not limited to patient who are high-risk surgical candidates, the patient does not desire surgery, and/or the recurrence of pain in the same location was sustained and consistently relieved with the SIJIs for at least three (3) months.
    4. The primary care provider should be notified regarding continuation of procedures and prolonged repeat steroid use to allow for systematic care delivery treatment surveillance and multidisciplinary biopsychosocial rehabilitation (MBR).
  10. A subsequent diagnostic SIJI is not reasonable and necessary when the initial diagnostic block does not produce a positive response of  75% pain reduction.
  11. A subsequent therapeutic SIJI is not reasonable and necessary when the proximate SIJI did not provide at least a consistent 50% pain relief or at least a 50% consistent improvement in the ability to perform previously painful movements and activities of daily living (ADLs) for at least three (3) months compared to baseline objective measurements for ADLS and painful movements or pain relief using the same pain scale*

**Provider Qualifications**

The Medicare Program Integrity Manual states services will be considered
medically reasonable and necessary only if performed by appropriately trained
providers.

Patient safety and quality of care mandate that healthcare professionals who
perform SIJ injections/procedures for chronic pain (not surgical anesthesia)
are appropriately trained and/or credentialed by a formal residency/fellowship
program and/or are certified by either an accredited and nationally recognized
organization or by a post-graduate training course accredited by an
established national accrediting body or accredited professional training
program whose core curriculum includes the performance and management of the
procedures addressed in this policy. Credentialing or privileges are required
for procedures performed in inpatient and outpatient settings.12

All aspects of care must be within the provider's medical licensure and scope
of practice. Reimbursement for procedures utilizing imaging techniques may be
made to providers who meet training requirements for the procedures in this
policy only if their respective state allows such in their practice act and
formally licenses or certifies the practitioner to use and interpret these
imaging modalities (ionizing radiation and associated contrast material,
magnetic resonance imaging, ultrasound). At a minimum, training must cover and
develop an understanding of anatomy and drug pharmacodynamics and kinetics as
well as proficiency in diagnosis and management of disease, the technical
performance of the procedure, and utilization of the required associated
imaging modalities.

**Notice:** Services performed for any given diagnosis must meet all the
indications and limitations stated in this LCD, the general requirements for
medical necessity as stated in CMS payment policy manuals, all existing CMS
national coverage determinations, and all Medicare payment rules.

**Definitions**

**Acute Pain** - an unpleasant sensory and emotional experience associated
with actual or potential tissue damage which is present for up to six (6)
weeks.13

**Baseline Pain** - **** An initial measurement of the pain which is taken at
a specified time point and used for comparison over time to look for changes
in the pain levels.

**Chronic Pain** - The temporal definition of pain persisting at least 12
weeks after the onset of the acute pain.

**Complex Regional Pain Syndrome (CRPS)** \- an array of painful conditions
that are characterized by continuing regional pain that is seemingly
disproportionate in the time or degree to the usual course of any known trauma
or other lesion. Pain is regional and usually has distal predominance of
abnormal sensory, motor, sub motor, vasomotor and or trophic findings.14

**Conservative Therapy** - Consists of an appropriate combination of
medication in therapeutic dosages (for example, non-steroidal anti-
inflammatory [NSAIDs], analgesics, etc.) administered for a sufficient amount
of time to determine efficacy, in addition to physical therapy, spinal
manipulation therapy, cognitive behavioral therapy (CBT), home exercise
program, or other interventions based on the individual's specific
presentation, physical findings, and imaging results.

**Consistent Improvement** - The percentage of improvement must have an
unchanging benefit and effect during the defined time period.

**Cryoanalgesia** - (cryoneurolysis) uses extreme cold (-70F to -180F) to
freeze nerves in an ice ball with the intent of interrupting transmission
along that nerve for pain reduction

**Disability** - Activity limitations and/or participation restrictions in an
individual with a health condition, disorder or disease.15

**Discogenic pain** - Pain originating from damaged vertebral disc,
particularly, but not always, due to degenerative disc disease.

**Efficacy Assessment Period** \- The duration of time the day before the SIJI
to weeks following the SIJI where assessments are made to determine the degree
of sustained and constant pain relief.

**Functional Impairment** - A physical or functional or physiological
impairment causes deviation from the normal function of a tissue or organ.
This results in a significantly limited, impaired or delayed capacity to move,
coordinate actions or perform physical activities and is exhibited by
difficulties in one or more of the following areas: physical and motor tasks;
independent movement; performing basic life functions.15

**GRADE** - A system developed by the GRADE Working Group to address the
shortcomings of present grading systems in healthcare. The GRADE system uses a
common, sensible, and transparent approach to grading the quality of evidence.
The results of applying the GRADE system to clinical trial data are displayed
in a table known as a GRADE profile.

**Multidisciplinary Biopsychosocial Rehabilitation (MBR)** - Targets physical
as well as psychological and social aspects of pain, and involves a team of
healthcare providers with different professional backgrounds and training.8

**Nonspecific low back pain** - Back pain that cannot be attributed to a
specific disease or spinal pathology.

**Radiofrequency Ablation** \- A procedure that uses radio waves that traveled
through electrodes to ablate (destroy) target tissue. For pain management,
radiofrequency-generated thermal energy is used to ablate the sensory nerve
fibers thereby interrupting nociceptive signals. Used interchangeably with
radiofrequency neurotomy in literature and policy.

**Primary (index) pain** - the level of pain measured prior to the injection
(aka baseline pain)

**Post-intervention Pain** \- the level of pain measured immediately after the
injection

**Sacroiliac Joint** \- The synovial joint formed at the juncture of the
sacrum and ilium.

**Sacroiliac Joint Complex** \- The articular portion of the joint, including
bone, articular cartilage and joint capsule and the posterior extraocular
structures which include the overlying dorsal ligaments, regional muscles, and
tendons.

**Sacroiliac Joint Pain** \- Pain from nociceptive signaling within and
surrounding a sacroiliac joint(s).16

**Sacroiliitis** \- Inflammation in one or both sacroiliac joints.

**Session** \- A session is a time period, which includes all procedures
(i.e., SIJIs and RFA ablations) that are performed during the same day.

**Spondylarthritis** \- A group of inflammatory arthritis affecting the axial
skeleton including the sacroiliac joint and spine with or without peripheral
joints and is often associated with HLA- B27.17

**Sustained and Constant Pain Relief** \- The pain relief must continue for
the defined time period and without interruption or regression to the primary
(index) pain.

**Subacute Pain** \- The temporal definition of pain occurring during the
6-to-12-week time period.

**Contractor Advisory Committee Meeting 3/10/2022**

A Multi-jurisdictional contract advisory committee meeting of subject matter
experts (SMEs) was convened on 3/10/22 regarding sacroiliac joint injections
and procedures. The transcript, voting results, and audio are available on
each MACs website. The panel consisted of experts in pain management including
anesthesiology and physical medicine and rehabilitation, as well as
neuroradiology, rheumatology, neurosurgery and a certified nurse anesthetist
with representation throughout the country and also included representation
from major pain societies. The panel will be referred to as SMEs, and their
input incorporated through the review to correlate the evidence with expert
input.

**Diagnosis**

SIJ disorders typically present with pain below the L5 level without numbness
or paresthesia and low back pain which is worse after prolonged sitting,
bending forward and transitions from sitting to standing. Pain also may be
worsened by weight bearing exercises including climbing stairs or even
prolonged walking. Gait compromise and referred pain to the buttocks, groin,
thigh and occasionally behind the knee are common. There is not a gold
standard for the diagnosis of SIJ pain. A combination of physical exams and
provocative tests (FABER, Gaenslen, Thigh Thrust or Posterior Shear,
Compression, Distraction and Yeoman Tests) are essential components to
determining SIJ disorders.3 Multiple studies show that 3 out of 5 tests are
suggestive of SIJ dysfunction with about 85% pretest probability that SIJ
injection will be successful,3,4,16,18 however this trend was not found to be
statistically significant.6 One meta-analysis showed that the thigh thrust
test, the compression test, and 3 or more positive stressing test have
discriminative power for diagnosing SIJ pain.4 A 2021 SR and MA assessing
clusters of pain provocation tests for SIJ dysfunction reported a 35%
certainty of having correctly identified SIJ pain from positive cluster
testing with GRADE rating for the outcomes of very low certainty.19 A small
diagnostic validity study to evaluate clinical examination using double
diagnostic injections as the reference standard reported a sensitivity of 91%
(62-98) and specificity of 83% (68-96) and positive likelihood ratio (95%
confidence intervals) of 9.97 (2.70-20.27) supporting the role of clinical
examination for diagnosis of SIJ pain.20

Imaging of the SIJ joint has the capability to confirm abnormalities in the
joint but is limited as it may not be diagnostic for SIJ disorders.
Conventional radiographs often do not correlate with the presence of low back
pain and can be abnormal in 25% of asymptomatic patients and CT scans can be
abnormal in up to 77% of asymptomatic individuals. Low sensitivity (57%) and
specificity (69%) of CT scans have been reported in patients with SIJ
pain.21,22 For patients with severe and intractable pain syndromes who have
failed medical/interventional treatment or for patients for whom there is a
concern for trauma, fracture, malignancy, or infection advanced imaging may be
required.22 If interventional therapy is planned, MRI of the lumbar spine is
recommended to rule out neural compression especially if the L5 nerve root is
involved.3 The diagnosis of spondylarthritis is characterized by sacroiliitis
on plain radiographs with or without bridging syndesmophytes, however early in
disease there may not be radiographic findings and MRI may detect changes
earlier than plain film.23 Imaging also plays a role in differential diagnosis
and exclusion of other lumbar spinal pathologies that may be causing symptoms.

A 2021 prospective evaluation reviewed over 2 dozen demographic, clinical and
technical factors on the treatment outcomes for 3 procedures, epidural steroid
injections, sacroiliac joint injections, and facet interventions in 346
patients. The initial block contained steroid and local anesthetic. A block
was considered positive when there was greater than 50% pain reduction lasting
at least 3 hours after the initial injection. Mean age was below the average
Medicare population. They determined that patients with greater disease
burden, depression and obesity were more likely to fail intervention. Sixty-
four percent of treatment failures were in obese patients compared to 35.8% of
successful procedures (p= 0.039). Obese patients also had a longer duration of
pain 6.7 years compared to 4.7 years (p= 0.01) in the non-obese population.
The authors observed that the higher threshold for blocks were associated with
higher likelihood of success with RFA, but at the risk of excluding patients
who may benefit. They did not find there was a statistically separate 1 month
outcome from using a < 80% relief point out for SIJ pain unlike those who
obtained between 50% and 79% pain relief, experiencing 80% immediate pain
relief did not statistically separate on 1 month outcome from having < 80%
relief, suggesting that many of these patients may have been placebo
responders.11

Their literature includes diagnosis of sacroiliitis, spondylosis, and
inflammatory spondyloarthropathies. Inflammatory arthritides as well as axial
and peripheral spondyloarthropathies may affect the SIJ joint. Our SMEs
confirm that inflammatory back pain may be due to inflammation at the site of
tendon attachments throughout the spine, with SIJ being one of the most common
sites. These patients warrant systemic treatment due to risk of developing
permanent bony damage that may be reduced or prevented with the availability
of highly effective therapies. Patients with symptoms of axial
spondyloarthropathies (SpA) are typically <45 years-old and should be
evaluated for these underlying conditions with appropriate laboratory, imaging
and genetic testing.24 Early disease may not have radiographic findings with
MRI being the most sensitive for detection of SIJ joint inflammation leading
to the Assessment of Spondylarthritis International Society (ASAS) criteria to
strongly recommend MRI of the SI joints for determination of sacroiliitis.25

**Conservative Management**

A significant portion of the patient population would be expected to improve
with time with or without intervention.26 Therefore, a trial of conservative
management is an accepted standard despite paucity of studies on conservative
measures. SMEs agreed that 4 weeks was a reasonable time for conservative
management in most cases. There was not sufficient literature to support
specific medications except topical capsaicin and NSAIDs with societal support
for muscle relaxants, and non-opioids and limited opioids as second-third line
options.27,28 There was evidence to support physical therapy (PT) with a SR
finding benefit of PT to reduce pain and dysfunction.29 SME review concludes
low quality, but existing, data to support PT, manual therapies, and exercise
interventions as potentially beneficial.30

**Diagnostic Injections**

Due to the lack of definitive history, physical exam, or radiological evidence
for SIJ dysfunction, diagnostic injections are recommended to rule out other
etiologies and ensure improvement in the SI joint to confirm diagnosis. In a
2021 review, accuracy of the injections was significantly improved by the use
of fluoroscopy and was more accurate than ultrasound (98% verses 87%).3

The number of diagnostic injections and percentage of pain relief is
controversial. In Buchanan's review the authors report Level II evidence for
dual diagnostic blocks with at least a 70% pain relief and Level III evidence
for single diagnostic blocks with 75% pain relief.3 The SI joint has both
anterior and posterior innervation with the joint itself being innervated
anteriorly by the lumbosacral trunks, obturator nerve and gluteal nerves. This
differs from the posterior innervation referred to as the posterior sacral
network consisting of the S1-S3 dorsal rami, and in some cases, fibers of the
L5 dorsal ramus. Therefore, there are 2 different pain generators with
different innervations.6,31-33 Diagnostic and therapeutic intraarticular
injections placed directly into the sacroiliac joint cavity anesthetizing the
articular nerves and potentially the surrounding ligaments but does not access
the posterior sacral network.

A single double blinded RCT with twenty subjects reported on the effectiveness
of multi-site, multi-depth sacral lateral branch injections into the
interosseous (IO) and dorsal sacroiliac (DSI) ligaments. Half of the subjects
received injections with corticosteroids while the other half received
injection with saline utilizing a multi-site, multi-depth lateral branch
injection technique followed by provocation testing which was compared to
baseline testing. They reported 70% effectiveness rate and that the intra-
articular portion of the SIJ is not blocked suggesting that multi-site multi-
depth lateral branch blocks to the IO and DSI are necessary to select patients
for RFA which target the posterior region of the SIJ complex.34

A 2019 comprehensive review acknowledged shortcomings of current literature.
The lack of consistent diagnostic criteria with approximately half of the
patients having a single diagnostic block before proceeding with RFA and high
risk of false positive rate compared to dual blocks throughout spine
literature may impact the overall outcome rates. The authors acknowledge the
limitation of current literature due to suboptimal/inconsistent selection
criteria, variable techniques and reliability creating lesions that will
denervate the SLBs as well as variability in assessment of response to
treatment resulting in a wide variety of outcomes within the literature. They
conclude this may underestimate success rates but report there is still
therapeutic effect with treatment responder rate ranging from 32% to 89%.31

In a 2015 systematic review, 10 reviewers assessed 45 publications on
diagnostic validity or effectiveness of fluoroscopically guided interarticular
SIJ injections.6 Papers were divided by degree of pain relief required for
positive response and presence or absence of controlled injections. The
authors concluded that controlled (dual) diagnostic block had a positive
response rate between 10% to 33% (with one outlier at 45%) while uncontrolled
(single) blocks reported a positive response rate between 29% to 63%
demonstrating that dual blocks significantly decrease the positive response
rate compared to single blocks. The investigators also reported increasing the
percentage of pain relief required for a positive block (>75% verses >50%)
decreased the reported prevalence of SIJ pain.

A 2012 systematic review of literature from 1996 to 2011 included patients
with back pain for 3 months or more and failed conservative measures using a
modi?cation of the United States Preventive Services Task Force (USPSTF)
methods to rate quality of evidence.35 Limitations included the paucity of
literature, and variations in technique and criteria for diagnosis of
sacroiliac joint pain. The authors rate the evidence for diagnostic accuracy
for sacroiliac joint injections as good, however that was based largely on
observational studies with only one placebo-controlled trial and no blinded
studies. They also rated the evidence for provocative maneuvers as fair,
imaging as limited and concluded support for ?uoroscopic guidance of the
injection. They conclude no signi?cant difference when 70% or greater relief
was used as the criterion standard with dual blocks as compared 50% or greater
pain relief reporting good evidence based on multiple high-quality studies.
However, this was based on one placebo-controlled study with small numbers
(n=40) and the remaining literature was observational or retrospective. The
authors concluded that the use of multiple blocks and high cutoff thresholds
would reduce the false- positive rate, however a stricter diagnostic criterion
may result in more false-negatives, and the potential to withhold treatment
from a patient who might bene?t.

A second systematic review in 2015 by the same authors was conducted to
evaluate the diagnostic accuracy and therapeutic effectiveness of sacroiliac
joint interventions.36 Eleven diagnostic accuracy studies were included, most
of which were also included in the 2012 SR and the same placebo-controlled
study. There was high heterogenicity between the studies, therefore, a meta-
analysis could not be performed. The authors concluded Level II evidence for
diagnostic accuracy is Level II for dual diagnostic blocks with at least 70%
pain relief as the criterion standard and Level III evidence for single
diagnostic blocks with at least 75% pain relief as the criterion standard
using a modified approach to grading evidence. The Level II was based on 2
studies considered high quality diagnostic studies with 70 (n=158) and 75%
(n=150) pain relief supported by dual blocks and prevalence of 26% and false-
positive rate of 20-26%. The single block studies showed a prevalence of
10-35%, with a wide variability and inconsistencies. The authors acknowledge
the controversy surrounding the diagnostic accuracy of controlled local blocks
however they opine that this is the best available tool to identify SIJ pain.

A 2020 review and algorithm for the diagnosis and treatment of SIJ pain
discusses the issue of intra-articular verses sacral lateral branch blocks and
the need to target the portion of the joint that is the pain generator.37 They
refer to Dreyfuss's study that found lateral sacral branch blocks were more
effective at preventing SIJ pain secondary to extra-articular (i.e.,
ligamentous) stimulation than from capsular distension.34 They also reviewed a
2015 SIJ fusion study that included 77 subjects and concluded that more than
half of the patients continue to experience at least 50% relief >6 months post
procedure. Predictors of treatment failure were the elderly, higher pre-
procedure pain scores, opioid usage, and pain radiating beyond the knee.37
They attributed this failure to the possibility that the RFA that targets the
posterior nerve supply of the joint and fails to address pain from the
anterior portion of joint with different innervation.

The SME panel presented both sides of the controversial topic of the number of
diagnostic joint injections and the percent pain relief required. Several
panel members felt that a single diagnostic injection was sufficient and
supported by evidence using a cutoff between 30 to 50%. They argue that the
higher false negative rate with dual blocks would exclude patients who may
benefit from the procedures and other procedures use a cutoff as low as 30%.
Other panelists felt that this would increase the incidence of false positives
and patients may be subject to repetitive procedures without definitive
diagnosis being established. Most of the literature as well as most
guidelines, utilized dual diagnostic blocks. The panel discussed sequential
care starting with conservative management and if no success proceeding to
diagnostic blocks, progression to therapeutic injections, then RFA and finally
fusion if pain relief is obtained but not sustained. In this case, a single
block may be sufficient because the next step in the algorithm would be
therapeutic injection which could also be a confirmatory injection. The panel
stated there was not specific evidence in terms of the duration of time
between the diagnostic blocks although standard practice is typically 2 weeks.
The response to blocks varies greatly depending on the type of anesthetic used
and whether corticosteroids were used, and that pain and improvement must be
measured before and after the block to determine success of the block.

**Therapeutic SIJ Injections**

Despite the common use of SIJI for management of SIJ complex pain there are
few studies that evaluate the effectiveness of SIJIs. There are 2 controlled
studies, both too small to determine statistical significance, and the
remaining studies are open and rarely prospective. The literature on SIJI is
challenged by lack of standardized patient selection, different kinds of
steroids in varying doses, different injection procedures, variability in use
of imaging to guide the procedure, various mechanisms, and duration for
assessment of response and risk of bias.6

Regarding the use of SIJI for axial SpA our SMEs explained that current
guidelines support the role of injections as an adjunctive role to aid in
acute pain relief, but not to replace systemic treatment which is the main
stay of treatment. The American College of Rheumatology Treatment Guidelines
for Axial Spondyloarthritis offers a conditional recommendation for SIJI is
based on 2 small RCTs with high risk of bias due to lack of blinding
concluding low quality evidence.39 This is supported by observational studies
as well. The SME conclude that SIJIs are appropriate for axial SpA conditions
with sacroiliitis as predominant or only feature while awaiting medication to
take effect or if there is contraindication for systematic therapy, but not as
a monotherapy due to high risk of disease outside the SIJ joint.39-41

Randomized Controlled Trials with Placebo Arm

A 1996 double blinded RCT on 10 patients with sacroiliitis (13 injections)
performed under fluoroscopic guidance reporting a 70% improvement at 1 month
for 5/6 that received steroids compared to 0/7 for those that received
placebo.42 Improvement was maintained at 3 and 6 months in around 60% of
injected joints. While their results were calculated to be statically
significant the small sample size was not adequate and there were no
diagnostic injections used.

In 1999 a RCT with 20 patients with seronegative spondylarthropathy and
clinical sacroiliitis (10 in each group) reported significant improvement in
Visual Analog Score (VAS) and pain index in those receiving unguided steroid
and lidocaine injection versus lidocaine and saline injection at 2
months.43,44

In 2002 the same group did another double blind, controlled study to
investigate the effect of SIJIs of corticosteroids and lidocaine (n=13) versus
lidocaine with saline (n=13) for non-spondylarthropathic patients with chronic
pain.44 Clinical assessment at the onset of the study and after one month
included VAS score and pain index. At one month both the VAS (p = 0.047) and
the pain index (0.017) had improved significantly in the corticosteroid group
compared with the placebo group. This study was limited by small sample size
and minimal follow up duration.

Systematic Reviews

Hansen et al.45 conducted a systematic review to evaluate the accuracy of
imaged guided therapeutic sacroiliac joint interventions in patients with back
pain for at least 3 months. The primary outcome measures were short term (<6
months) and long term per study descriptor (>6 months) pain relief, and
secondary outcome measures were improvement in functional status,
psychological status, return to work, and reduction in opioid intake.45

The authors conclude the evidence was fair in favor of cooled radiofrequency
neurotomy and limited (or poor) for short-term and long-term relief from
intra-articular steroid injections, periarticular injections with steroids or
botulin toxin, pulsed radiofrequency, and conventional radiofrequency
neurotomy.

Nine studies met the inclusion criteria and were clinically relevant; and the
small sample sizes, widespread variations in methodology, selection criteria,
outcome measures, and technique were limitations of the literature reviewed.

Dhir et al.17 conducted a systematic review to summarize the efficacy and
safety of systemic glucocorticoids (GC) and local injections of GC in
spondyloarthritis (SpA). Fourteen studies were identified using systemic GC in
SpA (364 patients); including 2 RCTs of oral prednisolone. On pooling data
from 2 placebo-controlled RCTs ( 24 weeks), Bath Ankylosing Spondylitis
Disease Activity Index (BASDAI50) was 4.2 times more likely to show
improvement (95% CI 1.5 to 11.5) and Ankylosing Spondylitis Disease Activity
Score 20 (ASAS) was twice more likely (95% CI 1.1 to 3.64) to improve high-
dose oral prednisolone ( taper). Pulsed GC led to dramatic improvements that
lasted a few weeks to a few months and there were no deaths or major adverse
events. There were 10 studies (560 patients) on local GC delivered by intra-
articular injections in SpA with sustained improvement in 51.5 to 90% joints
at 6 months. Despite known limitations the authors concluded there was good
evidence of efficacy with use of high-dose systemic GC in the short term ( 6
months) in SpA. Intra-articular or entheseal injections seemed safe and
effective.17

A systematic review was done to evaluate evidence on the comparative
effectiveness of surgery versus SIJIs for injection confirmed non-traumatic
sacroiliac joint pain.46 Twelve articles (7 surgical and 5 injection
treatment) were included, and most studies reported over 40% improvement in
pain and over 20% improvement in function as measured by Visual Analog Scale
or Numeric rating Scale score regardless of the type of treatment. Most
complications were reported in the surgical studies. No studies were
identified that compared surgical treatment with injection treatment in the
same patient population, so conclusions regarding the comparative
effectiveness of the treatments are not possible. Most studies were low
quality (mostly case series) and comprised small sample sizes and short
follow-up time, bringing into question the duration of treatment effect.
Direct comparisons of the interventions were difficult to interpret as the
study population was heterogeneous in terms of diagnosis, previous spinal
surgery, procedural details in the injection studies, and limited imaging
prior to fusion in some studies.

Other Studies

A 2022 retrospective review was conducted with 96 patients (107 injections)
with Ankylosing Spondylitis (AS) diagnosed by a rheumatologist with history,
physical exam and laboratory testing or by a radiologist with radiographic
evidence of bone marrow edema/osteitis on MRI who failed medical management
and underwent intra-articular sacroiliac joint injections.47 Limitations of
this study include the retrospective analysis, the inability to determine if
improvements were related to medication changes versus the injectable
treatment, especially since some patients were started on biological agents
during this time and 30% of patients had only been diagnosed for one month or
less so effectiveness of prior treatment could not yet be determined, and mean
age of 25 which is not representative of the Medicare population.

There are multiple open studies with concordant results demonstrating a high
percentage of patient improvement lasting several months providing some
confirmation of these results.40

A retrospective review concluded that extra-articular sources for sacroiliac
region pain exists, and intra-articular anesthetic blockade may underestimate
the true prevalence of sacroiliac region pain. Using 2 large case series
(n=120) patient responses to intra-articular injection versus combined intra-
articular and peri-articular injection of anesthetic and corticosteroid were
compared. For intra-articular injection alone, the rate of positive response
at 3 months was 12.50% versus 31.25% for the combined injection (P=.025).
Positive response was defined as greater than 50% drop in VAS pain score or
improvement in ADLs. Anesthetic response rates were higher in the combined
injection group (62.5% vs 42.5%; P=.037).48 Limitations include study design,
self-reported patient outcomes, and short follow up.

In a single blinded randomized trial by Viser et al.7 short-term therapeutic
efficacy of physiotherapy, manual therapy and image guided intra-articular
injection with local corticosteroids were compared. Patients were selected
based on a consistent diagnostic criterion including physical examination,
provocation test, X ray of the pelvis and MRI of the lumbar spine and SIJ
joints as well as laboratory testing to exclude other rheumatological
conditions. Out of 51 patients 25 (56%) were successfully treated based on VAS
score improvement: physiotherapy (PT) was successful in 20% (3/15), manual
therapy (manipulations) in 72% (13/18), and intra-articular injections in 50%
(9/18). The authors concludes that manual therapy appears to be the treatment
of choice for SIJ related leg pain with second line therapy being injection.7
Limitations include the lack of control group, small sample size, and short-
term follow-up.

A prospective randomized control trial comparing patients with sacroiliac
joint pain confirmed by diagnostic block of local anesthetic with 50%
improvement lasting 3 months or longer and failed conservative treatment
received image guidance SIJs or prolotherapy biweekly for a maximum of 3
injections. Pain and disability scores were assessed at baseline, 2 weeks and
monthly for 12 months. Twenty-three patients were randomized to the
prolotherapy group and 25 to the steroid group with improvement in scores in
both groups at 2 weeks. Cumulative incidence of greater than 50% pain relief
at 15 months was 58.7% in the prolotherapy group and 10.2% in the steroid
group. The authors conclude prolotherapy provided significant relief of
sacroiliac joint pain while the effects of steroids were low in this study.
Limitations included small sample size and mean age was less than the Medicare
mean population.49

**SIJ Denervation**

The posterior sacral network, which is the target of sacral lateral branch
radiofrequency ablation (SLBRFA), is innervated the S1-S3 dorsal rami, and in
some cases, fibers of the L4-L5 dorsal ramus. Systematic review analyzing
pooled data on the effectiveness of SLBRFA report approximately 50% of
patients report greater than 50% pain relief reduction at 3 months which is
less than the pain relief achieved with lumbar and cervical spine facet
blocks. The decrease in effectiveness may be due to limitations in patient
selection criteria, variations and procedural techniques and technology is
utilized. Most studies evaluating SLBRFA utilize single or dual intra
articular blocks for diagnosis of SIJ pain. This is problematic in that the
intraarticular blocks, which enter the SIJ joint and anesthetizes the anterior
complex, do not diagnose, or treat posterior sacral network pain. While
utilizing dual diagnostic blocks, also referred to as double infiltration
technique, has been suggested to improve selection of patients who may benefit
from RFA it is still not targeting the nerve that is being ablated and the
utility of this approach has been questioned.4,34,50,51 It is proposed that
sacral lateral branch blocks would better identify candidates for SLBRFA,
however there are no placebo controlled trials of sacral nerve blocks to
confirm this theory.51 In a 2009 double blinded RCT by Dreyfuss et al. multi-
site multi-depth sacral lateral branch blocks were evaluated in asymptomatic
volunteers. Seventy percent of the active group achieved loss of sensation
within the interosseous and dorsal sacroiliac ligaments and 86% retained the
ability to feel repeat capsular distention despite insensate dorsal SIJ
complex. The authors concluded that multi-site, multi-depth lateral branch
blocks were 70% effective and do not effectively block the intraarticular
portion of the SIJ joint. The authors predicted this could be a potential tool
to identify patients who may benefit from SLBRFA.34 However, there are no
studies that evaluate multi-site, multi depth or any other form of sacral
lateral branch blocks to predict success with SLBRFA.4 Multiple guidelines
have suggested this is a superior approach for patient selection for SLBRFA,
however there is not supporting data to confirm. While studies have shown some
predictive value of diagnostic intra articular blocks variations in patient
selection, criteria for positive SIJ block, radiofrequency ablation technique
and assessment tools are highly variable limiting the ability to produce
reliable meta-analysis and confirmatory results in the current literature.

Several different techniques for radiofrequency neurotomy including monopolar,
bipolar, cooled and palisade (strip) lesions have been utilized. There is not
sufficient evidence to state one technique is superior to the others. Cooled
RF is a novel technique in which internally cooled RF probes produce larger
lesions than is possible with other approaches. The primary advantage of
cooled RF technology is that it doubles the lesion's diameter and enhances the
volume by a factor of 8, making it more likely to interrupt the nociceptive
input from the sacroiliac joints. A different procedure called cryoanelgesia,
has been proposed for SIJ pain. There is minimal literature on the role of
cryoanalgesia for SIJ pain and the SME agree there is not sufficient evidence
to support cryoanalgesia of SIJ.

Randomized Controlled Trials with Placebo Arm

Our subject matter expert reported 5 sham-controlled studies regarding the
efficacy of SI joint RFA.52-57 The first 2 sham control trials published show
that in pooled, between-group comparisons, those treated with RFA were
approximately 4 times more likely to achieve 50% pain reduction at 3 months
compared with sham.52-54 Four of the 5 trials showed statistically better
outcomes for RFA compared to sham. Meta-analysis is limited by the high
heterogeneity within this literature, and various techniques for the ablation.

Cohen et al.52,53 performed a randomized placebo-controlled study to determine
whether sacroiliac joint denervation is a viable treatment for patients with
chronic, intractable sacroiliac joint pain. Participants included 28 patients
with injection-diagnosed sacroiliac joint pain using 75% or greater
improvement after a single diagnostic SIJ injection. Under local anesthetic
block, 14 patients received L4-L5 primary dorsal rami and S1-S3 lateral branch
radiofrequency denervation using cooling probe technology, and 14 patients
received placebo denervation. One, 3, and 6 months after the procedure,
11(79%), 9 (64%), and 8 (57%) radiofrequency-treated patients experienced pain
relief of 50% or greater measured by Numeric Rating Score (NRS) and
significant functional improvement measured by Oswestry Disability Index score
(ODI). In contrast, only 2 patients (14%) in the placebo group experienced
significant improvement at their 1-month follow-up, and no patient experienced
benefit 3 months after the procedure. Eleven crossed-over and were treated
with radiofrequency denervation using conventional technology of which 7
(64%), 6 (55%), and 4 (36%) experienced improvement 1, 3 and 6 months,
respectively after the procedure. One year after treatment, only 2 patients
(14%) in the treatment group continued to demonstrate persistent pain relief.
This was the first RCT with placebo suggesting that RFA may provide
intermediate-term pain relief and functional benefit in selected patients with
suspected sacroiliac joint pain and the authors called for larger studies to
confirm these results and to determine the optimal candidates and treatment
parameters acknowledging the limitation of the study due to small sample size
and inadequate blinding technique.

Patel et al.53,54 performed the second placebo controlled randomized trial of
51 subjects with chronic axial back pain and positive response to dual lateral
branch blocks with cutoff level of 75% or greater pain relief on NRS. Thirty-
four subjects were randomized to lateral branch neurotomy and 17 to sham
procedure. At 3 months subjects in the placebo group were allowed to crossover
and 16/17 subjects preceded with lateral branch neurotomy. At 3 months 47% of
treated subjects and 12% of sham achieved treatment success at 6 and 9 months,
respectively, 38 and 59% of treated subjects achieved success defined by a
statistically significant decrease in NRS, and disability and physical
function improvements between groups at 3-month follow-up. Strengths of this
study include the study design with a placebo-controlled arm, consistent
criteria for diagnosis, image guided injections with consistent protocol, and
standardized assessment for pain. Limitations include the small sample size
and cross-over design. Author concludes the results supports the
recommendation of cooled RF lateral branch neurotomy for persistent SIJ pain.

Patel et al. published on 12-month outcomes from the 2012 participants and
reported that the initial RFA group compared to baseline results were
favorable, with a mean 2.7 point drop in the NRS score, a 13.9 decrease in the
ODI, and a 15.8 increase in Short Form 36-physical functioning (SF36-PF). In
the crossover study group, 6-month outcomes were also favorable, with a mean
NRS score decrease of 2.5 points, a reduction in ODI of 8.8, and an increase
in SF36-BP of 11.9.57

Van Tilberg et al. reported in a double blinded randomized placebo controlled
multi-centered study which enrolled 60 patients with history and physical exam
suggestive of SIJ pain for greater than 3 months with a reduction of at least
2 points on NRS after a single diagnostic SIJI.55 Thirty patients underwent
percutaneous radiofrequency ablation applied to the lateral branches S1-S4 and
posterior rami of S5 while 30 underwent sham procedure. A crossover to RFA was
provided for 19 of the sham operated group at 3 months. No statistically
significant differences in pain level, satisfaction or other outcomes measured
over time between the groups nor within the treatment groups were found.
Unlike the other studies, the proportion of patients who reported significant
pain relief was higher in the sham group compared to the RFA group where 43.3%
experienced improvement. In the crossover group, 42.1% experienced a reduction
in NRS of 2 or more at 1 month (P= 0.65) which was consistent with the primary
treatment group results. The authors conclude no pain difference between
treatment and sham groups reporting a level 1A evidence. One possible
explanation of the differences in this study could be the use of a decrease in
NRS of two rather than 50-80% used in other studies resulting a high rate of
false-positive diagnostic blocks with 86% of SIJ test blocks being positive.
Also, the S4 branch could not be consistently reached with radiofrequency
probe. This study was not included in the analysis

A 2018 prospective, double blinded randomized sham controlled trial with 30
subjects who underwent dual intra-articular blocks using 80% pain relief as
cut off with seventeen reporting improvement.56 Eleven subjects were treated
with the radiofrequency ablation with a strip lesioning device (includes S1-S3
and L5 dorsal rami) and 6 underwent sham procedure. At 3 months, the mean
NRS-11 score for the active group had decreased significantly, from 8.1 (
0.8) at baseline to 3.4 ( 2.0) (P < 0.001) while the sham group did not
experience a statistically or clinically meaningful decrease in mean NRS-11
from baseline (7.3  0.8) to 3 months (7.0  1.7). Subjects who had RFA moved
from borderline anxiety at baseline (9.4  5.9) to no anxiety (6.6  6.3) at 3
months, but this was not statistically significant. While results were
reported to be similar at 6 months the sham group was allowed to cross-over at
3 months, so comparative data was not available. Eight non-serious adverse
events were reported in the RFA group including pain and flare up at the site
and one developed L5-S1 disc prolapse on the same side. Limitations small
sample size below minimum to detect clinical difference, short-term follow-up,
and mean age below Medicare population.

A large 2017 trial on RFA for facet, SIJ and intravertebral disc reported on
681 subjects and reported no clinically important improvement in low back pain
compared to standardized exercise program alone. The mean difference in pain
intensity between the RFA and control groups at 3 months was -0.71
(95%CI,-1.35 to -0.06) in sacroiliac joint trial.58 Diagnosis was made by
history and physical exam and one diagnostic injection with 50% improvement in
pain. Of 110 subjects who received SNRFA 81 received palisade RFA and 6 cooled
RFA with 116 included in the intention-to-treat analysis. Patients older the
age of 70 and BMI >35 were excluded. The authors conclude radiofrequency
ablation should not be performed outside of research setting and that
additional research is necessary for better patient selection and improvement
in techniques. This study benefited from large sample size, randomization, and
standard measuring tools for outcomes, but limited by lack of blinding, and
too small of a sample to distinguish any difference related to palisade vs
cooled RFA technique.

All studies required a single or dual diagnostic injection for diagnosis of
SIJ pain. Three studies used threshold of 75% or greater cut off for pain
while one study required a decrease in NRS of 2 or more points. Denervation
techniques varied between studies with all studies targeting S1 to S3 lateral
branch and the L5 dorsal ramus, and variability in S4 and L4 nerve roots which
also may have contributed to variability in results. High crossover without
intent-to-treat analysis limits the data to short term analysis at a maximum
of 3 months. Additionally, while there were no serious adverse outcomes
reported, the small sample sizes were not sufficient to determine long term
safety of the denervation procedure.

GRADE evidence analysis using GradePro software59 was conducted. Only studies
that offered a sham arm were included as these are the highest quality studies
available. Three placebo controlled RCTs were included. There was no SR/MA
that included all sham controlled RCT trials on RFA for SIJ pain, however
since there are no current studies to suggest one method of RFA is superior to
the others evaluation of all studies increases the pooled data to better
understand the available evidence. The first outcome of interest was pain
relief measured by NRS which was used in all the sham controlled RCTs studies.
NRS average at baseline and three months was reported by the authors which was
used to calculate a sum of difference between baseline and 3 months. These
values where then averaged to produce the final values. In the Mehta study,
data points were different in abstract than text, and data was obtained from
the text.55 The 2015 study by Patel was not included in evidence analysis with
GRADE since it was the same population as the Patel 2012 study and only the
initial subjects were included in analysis due to cross-over.53,54 The study
by Van Tilburg55 was a placebo-controlled study in which cross-over occurred
at 3 month and did not show a difference between sham and RFA group for NRS at
1 month, however there was no NRS data past 1 month so was not included in the
analysis. This study also had the highest adverse events reported. Quality of
evidence for RFA compared to placebo for suspected SIJ pain was very low
quality. The very low quality was a result of downgrading due to risk of bias,
missing outcome data, differences in interventions, and small sample size
(serious risk). Even removal of the difference in intervention from the
downgrading, a known factor in pooling this data, does not change the very
low-quality rating. The second outcome was adverse events with low quality
evidence. While there were few adverse events in the study population the
evidence was downgraded due to small sample size with less than 50 subjects
undergoing RFA in the pooled population and not sufficient data to be
confident the data represents the true risk of adverse events.

**Figure 1: Summary of Findings Table for RFA compared to placebo using GRADE
59**

**RFA (any type) compared to placebo for suspected SIJ pain in the Medicare
population for effective pain relief**  
  
---  
  
**Patient or population:** suspected SIJ pain in the Medicare population for
effective pain relief

**Setting:**

**Intervention:** RFA (any type)

**Comparison:** placebo  
  
Outcomes

|

**Anticipated absolute effects * **(95% CI)

|

Relative effect  
(95% CI)

|

No of participants  
(studies)

|

Certainty of the evidence  
(GRADE)

|

Comments  
  
**Risk with placebo**

|

**Risk with RFA (any type)**  
  
Pain Relief  
assessed with: Numeric Rating Scale (NRS)  
Scale from: 0 to 10  
follow-up: range baseline Baseline to 3 months

|

The mean pain relief by NRS was **-0.7**

|

Mean pain relief by NRS was **3.6 lower**  
(0 to 0 )

|

-

|

96  
(3 RCTs)

|

????  
Very low1,2,3,a,b,c

|

Small number of studies with small sample size, crossover design,
inconsistent. Adverse events reported but lack detail such as which study arm
subject was assigned.  
  
Adverse events

|

81 per 1,000

|

****

****

****

**0 per 1,000**  
(0 to 0)

|

not estimable

|

96  
(3 RCTs)

|

????  
Low1

|

Mehta-8 non-serious AEs reported by 8 patients (47.0%) (5 in the active, 3 in
the sham group). Cohen-no serious complications reported for either group. In
the radiofrequency treatment group, one patient reported transient nonpainful.
Patel-subjects reported soreness or numbness at the introducer sites in the 2
weeks following treatment.1 subject developed shingles was deemed unrelated to
treatment.52,53,56  
  
* **The risk in the intervention group** (and its 95% confidence interval) is based on the assumed risk in the comparison group and the **relative effect** of the intervention (and its 95% CI).  
  
 **CI:** confidence interval  
  
**GRADE Working Group grades of evidence**  
 **High certainty:** we are very confident that the true effect lies close to
that of the estimate of the effect.  
 **Moderate certainty:** we are moderately confident in the effect estimate:
the true effect is likely to be close to the estimate of the effect, but there
is a possibility that it is substantially different.  
 **Low certainty:** our confidence in the effect estimate is limited: the true
effect may be substantially different from the estimate of the effect.  
 **Very low certainty:** we have very little confidence in the effect
estimate: the true effect is likely to be substantially different from the
estimate of effect.  
  
_Explanations_  
a. Risk of Bias downgrade due to detection bias (blinding), incomplete
outcomes data.

b. Indirectness due to differences in interventions.

c. Imprecision downgraded due to small sample size.

Systematic review (SR)/Meta-Analysis (MA)

The Agency for Healthcare Research and Quality60 (AHRQ) SR/MA included
evaluation of cooled radiofrequency ablation procedures for sacroiliac joint
pain. Evaluation of the Cohen52 and Patel53 placebo-controlled RCT were
included and both were rated fair quality using AHRQ Methods Guide. The report
states cooled RFA for SIJ pain compared to sham (2 trials, N=79); demonstrates
short term outcomes improvements at 1 and 3-months reporting strength of
evidence moderate for pain and function at 3 months and low for function at 1
month. Additionally, they report that harms were not well reported but usually
temporary and related to increased pain with no serious complications reported
with strength of evidence low. They also point out that the mean age of
participants in these studies ranged from 52-59 which is below the Medicare
population.

Chen et al.61 conducted a meta-analysis to compare the clinical effectiveness
of radiofrequency (RF) neurotomy versus conservative nonsurgical approaches
for the management of chronic lumbar and sacroiliac joint pain. Five of 15
studies included reported sacroiliac joint pain with the rest on lumbar facet
joint pain. In the pooled data authors conclude patients treated with
radiofrequency neurotomy have significant greater improvement in ODI scores,
pain scores and QoL measurements compared with controls however, this data was
limited by significant heterogeneity from the pooled eligible studies,
inability to separate the SIJ data despite sub analysis and high risk of bias
necessitating larger studies are needed to confirm these findings.

Yang et al. conducted a SR on sacral lateral branch RFA and reported that the
targeted nerve branches treated in the 32 studies varied with 5 studies
targeting the L4 medial branch, 1 study targeting the S4 sacral lateral
branch, 24/32 studies included the L5 dorsal ramis, and all studies included
the S1 to S3 sacral lateral branches except for 2.31 Most studies were
observational and uncontrolled and only 2 placebo-controlled trials were
available. The type of radiofrequency ablation technology varied between the
studies and included conventional monopolar RFA, conventional bipolar RFA,
cooled RFA and stripped lesions. While the authors conclude RFA can provide
relief from posterior SIJ complex pain they found concern with the poor
selection rigor which they propose may explain the variability in success of
the RFA with positive outcomes ranging from 32 to 89%. They suggest improved
diagnostic protocols, the specific nerves targeted for ablation, and the types
of RFA technology and technique utilized may help to improve appropriate
patient selection and outcomes.

In Simopoulous et al.36 SR 14 therapeutic studies were reviewed using a
modified grading approach described in the paper. The authors conclude the
evidence for cooled radiofrequency neurotomy is level II-III. The evidence for
conventional radiofrequency neurotomy, intra-articular steroid injections and
periarticular injections with steroids or botulism toxin is limited at level
III to IV.

A 2015 SR using GRADE to assess the evidence of validity of sacral lateral
branch blocks and the effectiveness of sacral lateral branch thermal
radiofrequency neurotomy for sacroiliac complex pain.32 For multi-site, multi-
depth SLBBs the authors conclude moderate quality evidence based on positive
evidence from a single, well-designed RCT for therapeutic procedures.34 In
consideration of 15 studies on RFA the authors find moderate evidence for
sacral lateral branch thermal radiofrequency neurotomy, however evidence shows
relief is limited in extent and duration and the indication for the procedure
are not clear. They conclude that local anesthetic injections with or without
steroids are not sufficient for patient selection unless they are multisite,
multi-depth SLBBS which they feel is the only valid test for diagnosis of
sacral lateral branch pain. While this SR utilized GRADE criteria the only
included RCT accessing the validity of sacral lateral branch blocks was
challenged by small sample size with only twenty patients enrolled (ten in
active arm) and did not evaluate to role of sacral lateral branch blocks in
predicting SLBRFA success.

In a 2010 meta-analysis to assess the effectiveness of RFA of the SIJ for
reduction of pain by >50% post-RFA procedure at 3 and 6 months included 10
articles (1 RCT, 4 prospective observational and 5 retrospective studies).62
They conclude the MA demonstrated that RFA is an effective treatment for SI
joint pain at 3 months and 6 months. This was limited by lack of randomized
controlled trials, and the lack of standardization among the studies for
diagnostic criteria, RFA lesion techniques, pain scale and outcome measures
resulting in high heterogenicity which reduces the reliability of the MA.

A 2018 SR/MA on cooled radiofrequency ablation included 240 subjects from
retrospective, observational and two small RCTs.1 Due to pooling of studies
with different designs, high heterogenicity and small samples sizes the
results may not be valid.63 The author's acknowledge additional studies are
needed to confirm their conclusion that cooled RFA is safe and effective for
SIJ pain.1

A 2020 systematic review with meta-analysis designed to compare different
radiofrequency ablation techniques used for treatment of lumbar facet joint
and sacroiliac joint pain was conducted. A meta-analysis was performed despite
high heterogenicity which limits the analysis with I2 =92% and 96% for thermal
and cooled RFA respectively. The authors recognize the lack of standards in
the RFA techniques may be a cause of the high heterogenicity and that "our
results may not be reliable". They report a comparison of cooled
radiofrequency ablation, thermal radio frequency and pulsed radio frequency
results in improvement for lumbar facet joint and sacroiliac joint pain for up
to 6 months. However, the authors acknowledge that a comparison of the
efficacy among 3 radiofrequency techniques in the treatment of low back pain
has not been well investigated, and acknowledge the results lack a high level
of evidence and more high-quality trials are needed.64

A 2022 systematic review pairing thermal versus cooled radiofrequency ablation
in patients with sacroiliac joint pain included nine studies with a total of
276 patients. The meta-analysis reported overall pain reduction from the
random effects model was -3.485 (95% CI -4.144, -2.286) for VAS scores with
high heterogenicity (I2=75.65%, P<0.001). There was also reported improvement
in OID scores of -29.809 (-42.906, -16.713) with high heterogenicity
(I2=97.02%, P<0.001) The meta-analysis included all literature types including
case series with one RCT (Ib) and remaining literature graded II-III using
Cochrane's risk-of-bias tool. The authors conclude there was no statistical
difference between the two techniques examined and the literature is currently
lacking calling for additional studies period.65 This meta-analysis is limited
by pooling data from multiple study types and very high heterogenicity. While
meta-analysis has been conducted the results must be interpreted with caution
in light of this degree of heterogenicity, multiple different types of
literature pooled together, small sample sizes and high risk of bias which
limits reliability of meta-analysis and calls for further investigation as
stated by the study authors.63

A 2022 SR reviewed acknowledge the evidence to support RFA, in the form of
RCT, is "both thin and mixed" and state the lack of evidence beyond 12 months
post-intervention 16 RCTs were included of which 15 reported positive results
for RFA. Of significance many of the included studies reported RFA outcomes
for facet, SIJ, intravertebral disc or a combination and were not specific to
SIJ. The review did not breakdown the number of patients in each study that
had SNRFA specifically, with a larger portion undergoing facet RFA. The
reviewers included the largest study (n=681) which reported "no clinically
important improvement" from the RFA but reported valid criticism of the lack
of blinding of both the patients and investigators.66 The author acknowledges
the studies in Figure 1 above as the only sham-controlled studies specific to
SNRFA population. Meta-analysis was not conducted which was appropriate given
the high heterogenicity of the included studies. The SR concludes "taken in
aggregate" the total body of research supports this intervention however one
cannot draw conclusions about pooled data in this setting as they are
reporting a positive trend in RFA among several anatomical locations. The
inclusion of studies that evaluate facet which has a more robust body of
literature to support RFA than SIJ RFA and without a separate analysis of the
SIJ specific literature makes results inconclusive.

Randomized Controlled Trials with comparative arm (non-placebo)

A randomized blinded study with 30 patients with chronic low back pain
requiring regular analgesia and single positive diagnostic SIJ block requiring
75% or greater pain relief.67 Fifteen underwent radiofrequency generation of
S1 to L3 lateral sacral branch and L4-5 primary dorsal rami and 15 underwent
fluoroscopic guided SIJI with corticosteroids. Twelve patients in the steroid
group crossed over to receive RFA at 1 month and one at 3 months. In the RFA
group at 1-, 3-, and 6-months post-intervention, 73%, 60% and 53% of patients,
respectively, gained >50% pain relief. In the steroid group, at 1-month
postintervention follow-up, only 20% gained >50% pain relief. The authors
report failure to show any improvement at 3 month and 6 month follow-up in the
steroid group but given cross-over data was not analyzed the value of this
data past 1 month is not contributory. Most patients did not have pain relief
past 6 months in the RFA group. The study was limited by small sample size and
while there were no adverse outcomes, the sample size was too small to assess
safety and mean age was lower than Medicare population.  
  
Another randomized prospective study with 30 patients with a single diagnostic
block using 80% or greater pain relief to confirm SIJ dysfunction were
randomly assigned to articular steroid injections or pulse RFA of S1-S3
lateral sacral branches and L4-L5 dorsal rami.68 In the steroid group NRS
scores decreased from baseline (7.133  1.060) at 15 days (3.333  0.4880) and
one-month (3.333  0.4880) post-procedure with increase at three-months (4.400
 0.9856). In the RFA group NRS scores also decreased from baseline (7.067 
1.033) to 15 days (3.200  0.4140) with further decrease at 1 month (2.933 
0.5936) and stable at 3 months (3.067  0.8837) which was a statistically
significant difference compared to the SIJI group. At 6months pain scores rose
in both groups. ODI Score global perceived effect showed greater improvement
in the RFA group compared to injection. The study was limited by small sample
size, short duration of follow-up and lack of blinding introducing risk of
bias. While there were no adverse outcomes, the sample size was too small to
assess safety and the mean age was lower than Medicare population.

In another 2016 prospective, randomized comparative study of thermal
radiofrequency with sacroiliac joint block compared SIJI to bipolar thermal
radiofrequency.69 Sixty subjects with clinical exam suspicious for SIJ pain
and Visual Analogue Scale [VAS] > 6 and pain lasting more than 3 months were
randomized into three groups (n = 20 in each group): ultrasound guided SIJI
with local anesthetic/corticosteroid, conventional or modified (needle
distance >1cm) bipolar radiofrequency ''palisade'' of S1, S2, and S3 evaluated
at 1, 3 and 12 months. At 1 month there was >50% reduction in pain in all 3
groups (p < .001). The SIJI did not result in relief of pain at 3 and 12
months. The conventional RFA group reported pain relief at 3 months but not
sustained at 12 months. The modified RFA group reported improvement at both 3
and 12 months (p < .001). Hematoma was reported without serious adverse
events. Limitations of this study include inconsistent diagnostic/patient
selection criteria (not all patients received diagnostic blocks), lack of
control group, small numbers, lack of blinding introducing risk of bias and
mean age was lower than the average Medicare recipient.

A 2015 prospective, observational study, with data collection over 5 years,
was conducted at the authors' private practice to obtain a real-world view of
RFA treatment outcomes for SIJ pain.70 A cohort of 215 patients with SIJ pain
confirmed with dual diagnostic SIJIs with unknown cut-off for pain relief
underwent fluoroscopically guided SIJ RFA of the dorsal and lateral branches
of S1-S3 and the descending branch of L5. They reported an average pain
reduction of 2.3  2.1 NRS points following RFA (baseline pain score of 6.9 
1.7 to a follow-up average of 4.6  2.7 NRS points; p  0.01). Using a Likert
scale at a mean follow-up period of 14.9  10.9 months (range 6 - 49 months),
an overall 42.2% of patients reduced their analgesic use, 67% of patients were
satisfied with RFA outcome and 21/82 reported an improvement in employment
capacity leading to conclusion that RFA is a safe and effective treatment for
pain confirmed to originate from the sacroiliac joint. Limitations include
this was an observational study without a control group, single study site, no
precent improvement from procedure reported, type of RFA not reported, risk of
selection bias, unclear criteria for inclusion (percentage of pain relief
required from diagnostic blocks) and non-consecutive enrollment.

Other studies

Cohen et al.71 conducted a retrospective review seeking outcome predictors to
determine whether any demographic or clinical variables can be used to predict
SI joint RF denervation success. Pre-procedure pain intensity, age older than
65 years, and pain radiating below the knee were predictors of failure.
Regular opioid therapy showed a trend towards negative outcome. The use of
cooled, rather than conventional RF, was associated with a higher percentage
of positive outcomes. The authors conclude several factors were found to
influence outcomes including lack of a single clinical variable that reliably
predicted treatment results and the use of more stringent selection criteria
was not associated with better outcomes.

A prospective observational study evaluated 31 patients to which a new
technique for RFA that applied multiple electrodes simultaneously to the L5
dorsal rami and lateral branch blocks of the S1, S2 and S3 by creating a
stripped lesion from the lateral border of the base of the sacral superior
articular process to the lateral border of the S3 sacral foramen was used.
There was no sham group nor comparison to other RFA techniques however the
authors concluded the technique reduced operating time, X ray exposure and
cost as well as offered significant clinical improvement.72

A retrospective observational comparative study attempted to address if cooled
RFA is superior to traditional RFA in providing longer pain relief. They did
not determine there was a significant difference between the procedures and
both procedures reduced pain by >50% pain reduction for 3-6 months in majority
of the patients.73

A retrospective study was done to evaluate records from 126 patients with
physical examination and positive response (>50% pain relief) to an intra-
articular SIJ block who underwent cooled RF lateral branch neurotomy (LBN) of
S1-S3 and L5 dorsal rami to treat chronic SIJ-mediated low back pain. Visual
analog scale (VAS) pain scores, quality of life, medication usage, and
satisfaction were collected before the procedure, at 3-4 weeks post procedure
(N = 97), and once again between 4 and 20 months post procedure (N = 105).74
When stratified by time to final follow-up (4-6, 6-12, and >12 months,
respectively): 86%, 71%, and 48% of subjects experienced >50% reduction in VAS
pain scores, 96%, 93%, and 85% reported their quality of life as much improved
or improved, and 100%, 62%, and 67% of opioid users stopped or decreased use
of opioids. Limitations include a retrospective study design and lack of
control group to account for confounders, risk of recall bias and missing data
due to difficulty in contacting certain subjects.

A 2013 retrospective study of 20 charts of patients who had undergone cooled
RFA were reviewed 2 years after the procedure. 15/20 patients reported
significant reduction in pain based on a decrease of at least three points on
numerical rating scale. The authors conclude cooled radiofrequency denervation
shows long term efficacy for up to two years. Patients in this study were
diagnosed by a single positive diagnostic intraarticular SIJ injection.75
Another retrospective review included 41 consecutive patients who underwent
cold radiofrequency ablation after clinical diagnosis and greater than 50%
pain relief from a single intraarticular block. The authors report pain relief
lasted on average 5.5 months after the first radiofrequency ablation and nine
months after repeat radiofrequency ablation with the longest duration of pain
relief has 26 months. Both studies are limited by the study design without any
placebo-controlled or sham controlled group, no comparison to conventional
radiofrequency ablation, no accounting for other interventions during this
time, limitations in patient selection with single intra-articular SIJ block
and small sample size.

A 2015 prospective longitudinal cohort study including 32 patients diagnosed
with sacroiliac joint pain and confirmed with single positive diagnostic
intraarticular sacroiliac joint injection underwent conventional
radiofrequency ablation. Authors report an overall decrease in mean NRS pain
score decreasing from 7.7  1.8 at baseline to 2.8  1.2 at one month and to
3.1  1.9 at six months post-procedure (p < 0.001) with 27/32 reporting
satisfaction. Long-term pain relief was sustained at twelve- and eighteen-
months post-procedure, with NRS pain remaining at 3.4  2.1 and 4.0  2.7,
respectively. Mean age was below Medicare population at 58.3.77

While these studies suggest some potential long-term benefits there are too
many variables to draw a reliable conclusion. Without a comparison to placebo,
it is uncertain if the benefit is a result of the disease course improving
overtime, additional interventions the patient received throughout this time
period, a result of the radiofrequency ablation or placebo effect. Further
investigation would be necessary to delineate these factors.

2020 retrospective study 27 patients with SIJ pain refractory to conservative
treatment and on opioids with a single intra-articular diagnostic block
underwent cooled radiofrequency ablation. The authors report a decrease in
numerical rating score as well as a decrease in opioid use up to 12 months
post intervention reporting a 44.4% success rate in the RFA defined by
baseline NRS reduced by 50%. 18.5% did not use opioids during the follow-up up
to 12 months.78 While this is promising it is limited by the challenges with
the selection criteria, retrospective study design, potential influence of
physician prescribing practices, comorbidities including previous back surgery
in the patient population, considerable variation in the opioid use outcomes
and small sample size.

**Frequency and Laterality**

Sacroiliac joint pain is typically unilateral. Bilateral joint pain is less
common representing less than 10% of patients with SI joint disease. The
highest reported incidence of bilateral pain is in those with ankylosing
spondylitis and reactive psoriatic arthritis where bilateral sacroiliitis is
more common. The SME panelists stated that bilateral involvement is also more
common in the cases of elderly patients with degenerative disease. They also
expressed that in patients who have had a fusion bilateral pain is more common
and in patients who have relief on one side recurrence of pain on the opposite
side is not uncommon.

There is a lack of strong evidence in the literature to support exact
frequency or timing of SIJ injections. Subject matter experts found that
utilizing the existing literature, current guidelines, and similar types of
injections that no more than 2 injections per 6 months or 4 within a 12 month
periods were reasonable limitations. The current literature and guidelines
support at least a 50% relief in pain and/or function lasting a minimum of 8
to 12 weeks before repeating injections. This aligns with NASS Guidelines for
SIJ injections recommendation of 50% relief for 3 months.22 The QALY for SI
joint RFA following physical therapy and steroid injections is 2.52.78

There is also little data in terms of long-term treatment with therapeutic
injections. The subject matter experts advocated a progressive approach to
management. If a patient had relief from therapeutic injection(s) it may
provide sustained relief or it may reoccur. It is important to reevaluate and
assess for response and then have the patient return if pain reoccurs. The
panel felt that a very small proportion of patients should receive 3 or 4
therapeutic injections in a year.

**Safety**

The cumulative literature has shown few significant adverse events associated
with SIJIs and RFA procedures. Risk reported in the literature associated with
the injections include possibility of septic arthritis and sciatic nerve
palsy. There are also concerns about the risk of corticosteroids impact on
cartilage and articular cartilage and a SR confirmed higher doses (greater
than 3 milligrams/dose or 18 to 24 milligrams cumulative total/dose) for
longer treatment duration with corticosteroids were associated with
chondrotoxicity suggesting the importance of limiting use of corticosteroids
to 3 to 4 IA injections annually into any given joint and using minimal
steroid dosage possible.80,81 Several studies reported worsening pain shortly
after the procedure and one study reported transient non painful buttock
paresthesia, and hematomas.52,56,57,62,69

Image guidance reduces risk of injection outside of the joint. One study found
in patients who underwent blind SIJ injections, intra-articular needle
placement was confirmed on subsequent computed tomography (CT) scans in only
22%82 and another study of blind injections, only 5 of 60 needles closely
approximated the joint without any successful proper intra-articular
placement.83 The article also explains ultrasound cannot verify intra-
articular placement and CT is less effective than fluoroscopy at capturing the
escape of injected to the adjacent structures therefore fluoroscopy is the
preferred imaging modality.6 On the contrary, a study that compared
fluoroscopically guided injections into the joint capsule to blind injections
to the point of maximal tenderness using sham radiographs determined there was
no significant difference in pain score at 1 month, and modestly decreased in
the fluoroscopically guided group as compared to the blind injection group at
3 months.83 The authors concluded that fluoroscopic guided injections provided
greater intermediate benefits in some patients the differences were modest,
and costs were increased. Adverse outcomes were reported in 6% of
fluoroscopically guided group compared to 12% of landmark-guided (p=0.36).83
While this was not statistically significant, 61 patients receiving blind
injections is not sufficient to assess the safety of this technique. In a
prospective randomized study that compared ultrasound guided to
fluoroscopically guided SIJ injections the authors concluded that function and
pain relief were significantly improved in both groups. Ultrasound guidance
was limited as 87.5% (US) verses 98.2% (fluoroscopy) were successful. However,
when successful it offered good visualization of the vasculature and concluded
that it was as effective as fluoroscopic guidance for treatment approach.84

The American Society of Anesthesiologists provides definitions on the
continuum of the depth of sedation. Minimal sedation anxiolysis is defined as
a drug-induced state during which patients respond normally to verbal
commands. Although cognitive function and physical coordination may be
impaired, airway reflexes, and ventilatory and cardiovascular functions are
unaffected. Progressing depth of sedation beyond minimal is moderate or
"conscious", deep and general. Monitored Anesthesia Care or "MAC" is not a
depth of sedation, but a specific anesthetic service allowing a deeper level
of analgesia than can be provided by moderate sedation.10

The American Society of Anesthesiologist also provides guidelines for
anesthetic care during interventional pain procedures for adults stating that
when sedation is provided during the performance of pain procedures it is
important that the patient can be responsive during critical portions of the
procedure to report potential procedure related paresthesia, acute changes in
pain intensity or function for potential toxicity. The committee opinion
states that interventional pain procedures generally only require local
anesthetic however patients may elect to also receive supplemental sedation
but must remain conscious. Examples of procedures that typically do not
require moderate sedation and/or an anesthesia care team include sacroiliac
joint injections. They also state that significant patient anxiety, medical
comorbidities, procedures that require the patient to remain motionless for
prolonged periods of time or remain in a painful position may require moderate
sedation or anesthesia care team and an example of such a procedure is
radiofrequency ablation.10

The subject matter expert panel agreed that sedation is not necessary for
injections but may be appropriate in select cases of RFA. The panel also
expressed concerns that sedation could increase risk as well as the validity
of diagnosis.

**Societal Guidance**

_North American Spine Society (NASS)_

_2020 NASS Diagnosis and Treatment of Low Back Pain Guidelines 22 the
following recommendations pertain to SIJs:_

  * There was insufficient evidence to recommend non-specific physical exam maneuvers for assessment of SIJ pain or for or against obtaining laboratory tests to assess for inflammatory disease in patients with SIJ pain. Regarding efficacy of fluoroscopic guided SIJI the panel concludes intra-articular steroid joint injections may be considered in patients with suspected SIJ pain: Grade of Recommendation: C based on Level IV evidence. Statistically significant improvement in disability, pain and work status overtime was found in patients who had an 80% improvement from diagnostic sacroiliac joint injection followed by an intra-articular steroid injection. The average number of injections was 2.1.
  * The panel concluded that in patients with temporary pain relief provided by SIJIs cooled radiofrequency ablation of the sacral lateral branch nerves and the dorsal ramis of L5 may be considered in patients with SIJ pain diagnosed with dual diagnostic blocks: Grade of Recommendation: C based on Level IV evidence. The reviewed studies required 50% and 75% dual diagnostic blocks prior to RFA.
  * The panel concluded insufficient evidence to determine if SIJ fusion compared to medical intervention improved pain and function. 

_2020 NASS Coverage Policy Recommendations for Sacroiliac Joint Injections &
Radiofrequency Ablation:5_

  * Diagnostic blocks for evaluation for SIJ pain is appropriate if the following criteria are met: 

a) Patient's report of nonradicular, typically unilateral, pain that is
maximal below the L5 vertebrae, localized over the posterior SIJ, and
consistent with SIJ pain.

b) A physical examination typically demonstrating localized tenderness with
palpation over the sacral sulcus (Fortin's point, ie, at the insertion of the
long dorsal ligament inferior to the posterior superior iliac spine or PSIS)
or the absence of tenderness elsewhere (e.g., greater trochanter, lumbar
spine, coccyx) that would explain the patient's symptoms.

c) Positive response to a cluster of at least three provocative tests (1.
Patrick's or FABER, 2. Gaenslen, 3. Thigh thrust, 4. Sacral thrust, 5.
Distraction, 6. Compression).

  * Blocks should be performed with image guidance and injectant limited to 2mL.
  * The guidelines distinguish between intra-articular injections and diagnostic blocks. Intra-articular injections target the SIJ intra-articular surfaces and capsule and are recommended for diagnosis of SIJ pain. Diagnostic blocks of the L5 primary dorsal ramus and sacral dorsal rami lateral branches (S1-S3) are aimed at the dorsal and interosseous ligaments and aid in the diagnostic work-up of low back pain. According to these guidelines diagnostic blocks should performed prior to RFA using small volume (<0.5mL per nerve) image-guided anesthetic blocks. For either block a positive response is at least 75% reduction in pain for the expected duration of the anesthetic used on two separate occasions.
  * Therapeutic injections:  
Image-guided intra-articular SIJ injections of corticosteroid with or without
local anesthetic are indicated for the treatment of sacroiliac pain when  1
of the listed criteria are met:

a) Clinical criteria for diagnostic SIJ injection are met (as above) AND pain
has been present for at least 1 month AND pain is  4/10 with functional
limitation OR any pain level with functional limitation despite other
conservative treatment.

b) SIJ pain has been confirmed with diagnostic intra-articular SIJ injections.

c) SIJ pain has recurred following a previous therapeutic SIJ injection which
resulted in >50% pain relief for  3 months.

d) Advanced imaging (bone scan or MRI) demonstrates uptake or inflammation in
the SIJ.

e) Patients with spondyloarthropathies such as ankylosing spondylitis.

  * Radiofrequency neurotomy: 

Image-guided thermal radiofrequency neurotomy of the L5 primary dorsal ramus
and sacral dorsal rami lateral branches at S1, S2 and S3 are indicated for the
treatment of sacroiliac pain when either of the listed criteria are met:

a) Clinical criteria for positive diagnostic anesthetic blocks of the L5
primary dorsal ramus and sacral dorsal rami lateral branches (as above) are
met AND pain has been present for at least 3 months AND pain is severe enough
to cause some degree of functional deficit despite other conservative
treatment.

b) Posterior sacroiliac ligament complex pain has recurred after = 50%
improvement for  6 months from prior radiofrequency neurotomy of the L5
primary dorsal ramus and sacral dorsal rami lateral branches.

_Spine Intervention Society (SIS) Appropriate Use Criteria for
Fluoroscopically Guided Diagnostic and Therapeutic Sacroiliac Interventions:
Results from the Spine Intervention Society Convened Multispecialty
Collaborative 85_

  * SIS guidelines were developed in collaboration with the American Academy of Orthopaedic Surgeons, American Society of Anesthesiologists, American College of Radiology, American Academy of Physical Medicine and Rehabilitation, American Academy of Pain Medicine, and North American Spine Society and evidence quality evaluated with GRADE. The panel concluded no high-quality evidence therefore the guidelines are largely based on clinical expertise utilizing a rating scale of more than 10,000 clinical scenarios each evaluated twice.
  * Brings up the conundrum that while 50% of patients receive pain relief with radiofrequency neurotomy of the lateral branches of the sacral dorsal rami most of the studies selected were based on their response to intra-articular sacroiliac joint injections rather than diagnostic blocks of the sacral lateral branches which are the target of the therapeutic procedure.
  * The panel felt clinical exam and provocation maneuvers should be required and that maximal pain above the L5 vertebrae negatively correlated with a recommendation for SIJ injection, while 3 or more positive provocation tests were a positive correlation. There was no requirement for imaging. The panel preferred injection with local anesthetic and steroids rather than local anesthetic alone for the potential additional pain relief and the panel did not feel it was appropriate to perform lateral branch blocks as the first intervention.
  * The panel recommendations were to not withhold anticoagulation or antiplatelet medication prior to injection of the SIJ or lateral branches based on lack of bleeding complications reported in the literature. Additionally, lack of sensitive neural structures that could be damaged by hematoma was not an issue in this region. Holding anticoagulation places the patient at greater risk from the underlying condition for which they are being treated.
  * The panel felt that SIJ injections were appropriate for the patient who has had pain for more than 1 month, intensity greater than 4/10 and causing functional limitations regardless of whether conservative therapy has been provided. There was also discussion that by giving the first injection with local anesthetic and steroids they are providing a therapeutic agent to a patient who has yet to be diagnosed with sacroiliac pain. While this benefits the patient with a positive response to the local anesthetic it risks administering steroids to someone who may not benefit. It was the opinion of the panel that injection of steroid with local anesthetic, injection of steroid alone or lateral branch blocks would be appropriate following an initial diagnostic injection of local anesthetic that provided greater than 75% pain relief. Injections of local anesthetic and steroid were considered appropriate if there was at least 50% pain and repeat injections required at least 50% pain relief from the initial therapeutic injection. Additionally, they went on to say that if the patient had an injection of steroid alone that they should have at least 75% relief for 2 months.
  * Two key factors, duration of symptoms and degree of pain relief obtained during the block, were identified for evaluation of indications for RFA. The panel felt the symptoms should be present for at least 2 months prior to the procedure and that a minimum of 50% pain relief from diagnostic injections was insufficient to proceed with RFA. The panel agreed that pain relief needed to be at least 75% to proceed with procedure. For repeat RFA, they felt that the first RFA had to result in at least 50% pain relief and the effects last at least 3 months. They concluded the type and sequence of blocks obtained intra-articular versus lateral branch block had minimal effect on the outcome and were most relevant for those with 50 to 75% pain relief and in those with only 2-3 months of symptoms. 

_The American Society of Interventional Pain Physicians (ASIPP) Comprehensive
Evidence-Based Guidelines for Interventional Techniques in Chronic Spinal Pain
Part II: Guidelines and Recommendations: 86_

  * Evidence for diagnostic sacroiliac intra-articular injections is good with 75% to 100% pain relief as criterion standard with controlled local anesthetic or placebo blocks leading to recommendation for diagnostic SIJIs in individuals suspicious of SIJ pain with  75% improvement in pain or ability to perform previously painful movements.
  * For sacroiliac joint interventions, the evidence for cooled radiofrequency neurotomy is fair; limited for intra-articular injections and periarticular injections; and limited for both pulsed radiofrequency and conventional radiofrequency neurotomy. 

_International Society for the Advancement of Spine Surgery (ISASS) Policy
2020 Update- Minimally Invasive Surgical Sacroiliac Joint Fusion (for Chronic
Sacroiliac Joint Pain): Coverage, Indications, Limitations and Medical
Necessity 26_

  * Imaging may be beneficial for inflammatory sacroiliitis and acute trauma but no imaging modality has acceptable sensitivity and specificity for non-inflammatory, non-traumatic SIJ pain.
  * ISASS state intra-articular SIJI may be considered but not required due to a lack of high-quality evidence supporting short- or long-term effectiveness of the treatment and three randomized control trials comparing injection to radiofrequency ablation have been published without demonstration of improvement in pain or function in 1 month after the injections. They do not recommend repeat SIJI with steroids and state concern regarding accelerated cartilage degeneration in the hip and knee and lack of cost effectiveness data.
  * ISASS concludes SIJ RFA may be considered but not required and there is modest evidence to support safety and effectiveness. They report while there are randomized control trials to support this technology, there is no standardized patient selection algorithms, no standardized technology or techniques and the literature has mixed results. They conclude treatment with repeat RFA is not recommended.
  * ISASS recommend diagnostic blocks to confirm the diagnosis of SIJ with a small volume of local anesthetic. There is concern that extravasation of injectant can compromise diagnostic capabilities. Regarding use of SIJ to selection patients for fusion. ISASS states that injection of the intra-articular portion of the joint does not predict outcomes to fusion and there is not sufficient evidence to support this practice. They expressed concern that an overly stringent selection criteria such as 75% has no basis in evidence and is likely to result in withholding a beneficial procedure from a substantial number of patients with significant pain and functional impairment. 

_Assessment of Spondyloarthritis International Society- European League
Against Rheumatism: 87_

  * ASAS-EU recommendations include glucocorticoid injections directed to the local site of musculoskeletal inflammation may be considered. Patients with axial disease should not receive long term treatment with systemic glucocorticoids. 

_American College of Radiology (ACR), Spondylitis Association of America
(SAA), and Spondyloarthritis Research and Treatment Network (SPARTAN): 39,41_

ARC/SAA/SPARTAN guidelines give a conditional recommendation for SIJIs for
patients as an option for patients with isolated active sacroiliitis despite
the use of NSAID acknowledging this recommendation was supported by very low-
quality evidence. They recommend avoiding peri-tendon injections and
acknowledged the recommendation was extrapolated from experience in other
diseases and feel this option is best for patients who prefer local over
systemic treatment and when only one to two joints are inflamed. The 2016
update of the Assessment of Spondyloarthritis International Society/European
League Against Rheumatism management recommendation for SpA, states
glucocorticoid injections directly into the local site of musculoskeletal
inflammation may be considered and is preferred over treatment with systemic
glucocorticoids offering a level of evidence of II and a grade of
recommendation of B on the GRADE scale.

_American Society of Pain and Neuroscience (ASPN) Best Practice Guidelines:
51_

  * Lateral sacral branch radiofrequency neurotomy may be used for treatment of posterior sacral ligament and joint pain following positive response to appropriately placed diagnostic blocks. GRADE II-I (Well, designed controlled, nonrandomized clinical trials) B (USPSTF recommends the practice/ moderate benefit).
  * The authors recommend lateral sacral branch blocks prior to performing RFA even in cases where previous SIJ injections with the intra articular approach were performed using a 50% or greater reduction in pain prior to advancing to RF.

The literature for sacroiliac joint pain is limited by few placebo-controlled
randomized trials, lack of long-term data, inconsistencies in diagnostic
criteria, assessment of outcomes, and techniques of procedures resulting in
high heterogeneity between the studies. The overall quality of the literature
is low, leading to many unanswered questions on best practices and the true
effectiveness of the procedures. However, there is a consistent trend to
improvements in pain after the SIJ injections in a subset of patients
suggesting there is benefit and offers a viable treatment option that may
improve pain and quality of life and function in some sufferers. SIJIs may
provide relief for those suffering from inflammatory spondyloarthropathies
while awaiting systemic therapy to become effective. The optimal patient
selection, treatment and algorithm for care has yet to be clearly defined in
the literature.

SIJ pain is based on clinical evaluation and physical exam with three positive
provocative maneuvers increasing the likelihood of SIJ as the source of pain.
Exclusion of other etiologies is important and may require imaging depending
on the presenting symptoms and examination. Due to inconsistencies in the
diagnostic criteria, confirmation with diagnostic injection(s) is indicated
based on the current literature. The percent improvement in pain is
controversial, however, most studies utilized a 75% or higher cutoff for pain.
While some argue a less stringent cutoff should be utilized, there is not
sufficient data to support this approach. Given that many of these patients
will progress to repeat injections or surgical management correct diagnosis is
necessary, so the more stringent criteria are indicated. This is consistently
supported by the literature and societal guidelines.

The literature is unclear on the long-term effectiveness of therapeutic
sacroiliac joint injections. Repetitive injections of corticosteroids do
involve risk therefore long-term management with this approach should include
a multidisciplinary team and notification of the primary care provider to
assess impact on other health conditions. Guidelines suggest the mean number
of injections is two. Repetitive injections are typically less common as
patients with persistent pain will often move to surgery for long-term
management. After the initial diagnostic injection, the first therapeutic
injection can serve as a confirmatory diagnostic injection as well as a
treatment. Pain relief of greater than 50% for at least 2 to 3 months would be
expected based on the current evidence for a positive result.

The frequency and duration between treatment is also not clear in the
literature, however guidelines address this topic. There was consistency in
the guidelines and SME input that therapeutic injections should be given at a
minimum of 2 months and more typically 3 months apart leading to a frequency
limit of a maximum of 4 injections in a rolling 12 months, understanding that
use of more than 2 SIJI is not standard.22,74 Bilateral administration, while
may be appropriate in some cases, is also not standard.

Multiple guidelines, SME input and one paper suggest that intra-articular
injections may not be optimal for selection for radiofrequency ablation.
Because radiofrequency ablation focuses on the posterior nerves, they
recommend lateral sacral branch blocks (targeting dorsal and interosseous
ligaments) to better select appropriate patient for RFA of SIJ, however there
is insufficient evidence for this recommendation. It is possible that spread
of the anesthetic and steroids out of the intra-articular space may be
responsible for some of the positive results for patients who have been
selected utilizing the intra-articular approach. This presents a conundrum as
the diagnostic injections used to confirm the presences of SIJ pain are not
targeting the nerve which is being ablated during SLBRFA. Dreyfuss et al.34
provides support that multi-site, multi-depth lateral branch blocks do not
effectively block the intra-articular portion of the SIJ and suggest lateral
branch blocks may serve as a better predictive tool, but that is not used in a
single study on RFA all of which use the intra-articular approach with
variable results. While guidelines recommend the use of lateral sacral branch
blocks to predict optimal candidates for RFA this is not validated in any
studies.

The literature shows a positive trend for SIJ RFA pain improvement and most
subject matter experts on our panel support this as a treatment option. While
meta-analysis that have been done in attempt to reconcile the small sample
size extremely high heterogenicity in these studies is problematic. Some meta-
analysis attempt to pool data from various procedures including facet RFAs66
or combine multiple study types into a single MA1 which does not yield
reliable results. The AHRQ SR/MA includes only cooled RFA to reduce the
heterogenicity and concluded the evidence was fair quality with moderate
strength of evidence at 3 months for RFA for pain and function but was limited
by small sample size (n=79). There are no studies to determine if one
technique of RFA is superior to the others. To further evaluate the literature
evidence analysis using GRADE was conducted with primary outcome of change in
NRS at baseline and 3 months after RFA (Figure 1). NRS was selected as it was
the only consistent measurement among the RCTs. This analysis concludes very
low-quality evidence for RFA compared to placebo for SIJ pain. Additional
studies are challenged by methodological flaws, small sample sizes, cross-over
design, inconsistency, incomplete data and variability in patient selection
and procedures performed.

For a service to be considered "reasonable and necessary" under 1862(a) (1)
(A) of the Act it must be furnished in accordance with acceptable standard
medical practice for the diagnosis or treatment of the condition.12 To meet
this requirement, an acceptable standard must be established and supported by
the medical literature. There is insufficient evidence to determine a
diagnostic criterion for identifying patients who may benefit from RFA. The
existing studies report effectiveness outcomes that are based on selection
criteria (intraarticular SIJ) that have been refuted within the literature and
by experts creating a conundrum. Despite expert opinion suggesting SLBB
criteria this lacks both evidence and clarity leading to tremendous
variability within current practices and in patient outcomes (ranging from
32-89%). The lack of established practice standards, patient selection
assessment criteria, frequency of treatment and long-term outcomes in the
existing literature necessitates additional investigation to develop
appropriate use criteria that can establish optimal patient selection and
confirm effectiveness in properly selected patients to meet criteria for  
reasonable and necessary.