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 SIJ 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 SIJ has variable joint capacity as the
SIJ 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 (SIJIs) and
radiofrequency ablation (RFA) of the SIJ. Injections typically are intra-
articular and contain anesthetic and corticosteroids. Ablation relies on RF-
generated thermal energy to ablate the sensory nerve fibers of the SIJ,
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. SIJIs**  will be considered medically reasonable and necessary when all
the following requirements are met:

  1.     1. Moderate to severe LBP primarily experienced over the anatomical location of the SIJs between the upper level of the iliac crests and the gluteal fold, **AND**
    2. LBP duration of at least 3 months, **AND**
    3. LBP 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 3 positive findings with provocative maneuvers: FABER, Gaenslen, Thigh Thrust or Posterior Shear, SI Compression, SI Distraction and Yeoman Tests,3,4 **AND**
    6. LBP persists despite a minimum of 4 weeks of conservative therapies.5

**B. Diagnostic SIJIs**

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

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

  1.     1. The patient must meet the above criteria for _Covered Indications_ for SIJI, **AND**
    2. The SIJIs must be performed under computed tomography (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. SIJI are not performed with other musculoskeletal injections in the lumbosacral spine, **AND**
    4. The documentation should show direct causal benefit from the SIJI 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 SIJI, 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 2 diagnostic joint sessions, unilateral or
bilateral. To clarify, 2 unilateral sessions, if performed on 1 side at 1
session and on the opposite side at a different session, would meet the
limitation of 2 diagnostic sessions.

**C. Therapeutic SIJI**

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

  1.     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 SIJI, post-intervention on the day of the diagnostic injection, and the days following the diagnostic SIJI 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 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 SIJIs 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

Limitation: No more than 4 therapeutic SIJI sessions, unilateral or bilateral,
will be reimbursed per rolling 12 months. To clarify, a therapeutic SIJI
session if performed on 1 side first and then on the opposite side at a
different session would qualify as 2 sessions for the limitation of 4
therapeutic SIJ sessions per rolling 12 months.

**D. SIJ Denervation** (also called 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 LBP 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 SIJI 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 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 ADLs it is insufficient to provide a vague or nonspecific statement regarding the improvement of previously painful movements and 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 (epidural steroid injection (ESI), sympathetic blocks, facet blocks, trigger point injections, etc.) during the same session as SIJIs and during the post SIJI efficacy assessment period.
  4. Use of Moderate or Deep Sedation, General Anesthesia, and Monitored Anesthesia Care (MAC) is usually unnecessary or rarely indicated for SIJIs, 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 LBP, axial spine pain primary above the level of L5, complex regional pain syndrome (CRPS), 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 LBP 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 (MBR) 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 over 12 months may trigger a focused medical review. Use beyond 12 months 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 3 months.
    3. Rationale for the continuation of SIJIs, including but not limited to, patients 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 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 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 ADLs for at least 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 SIJIs/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 LCD. 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
LCD 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 (MRI), 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
NCDs, 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 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 1 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 LBP - **Back pain that cannot be attributed to a specific
disease or spinal pathology.

__

**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

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

**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 SIJ.16

**Sacroiliitis-** Inflammation in 1 or both SIJs **.**

****

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

**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.

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

****

**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 SIJIs 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 LBP 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 SIJI will be successful3,4,16,18; however,
this trend was not found to be statistically significant.6 One meta-analysis
(MA) 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 Systematic Review (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 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 LBP 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, SIJIs, 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 arthritis as well as axial
and peripheral spondyloarthropathies may affect the SIJ. Our SMEs confirm that
inflammatory back pain may be due to inflammation at the site of tendon
attachments throughout the spine, with SIJ being 1 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 inflammation leading to the Assessment of
Spondylarthritis International Society (ASAS) criteria to strongly recommend
MRI of the SIJs 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 SIJ 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 SIJ 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 SIJ cavity anesthetizing the articular nerves and
potentially the surrounding ligaments but does not access the posterior sacral
network.

A single double blinded randomized control trial (RCT) with 20 subjects
reported on the effectiveness of multi-site, multi-depth sacral lateral branch
(SLB) 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 SR, 10 reviewers assessed 45 publications on diagnostic validity or
effectiveness of fluoroscopically guided inter-articular SIJIs.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
1 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 SR of literature from 1996 to 2011 included patients with back pain for
3 months or more and failed conservative measures using a modification 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 SIJ pain. The authors rate the
evidence for diagnostic accuracy for SIJIs as good; however, that was based
largely on observational studies with only 1 placebo-controlled trial and no
blinded studies. They also rated the evidence for provocative maneuvers as
fair, imaging as limited and concluded support for fluoroscopic guidance of
the injection. They conclude no significant 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 1 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 benefit.

A second SR in 2015 by the same authors was conducted to evaluate the
diagnostic accuracy and therapeutic effectiveness of SIJ 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 MA 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
(SLBB) 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.39-41

_RCTs 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 spondyloarthropathy 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-spondyloarthropathic patients with
chronic pain.44 Clinical assessment at the onset of the study and after 1
month included VAS score and pain index. At 1 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 SR to evaluate the accuracy of imaged guided
therapeutic SIJ interventions in patients with back pain for at least 3
months. The primary outcome measures were short term (<6 months) and long term
(>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 RF 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 RF, and conventional RF 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 SR 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 SR was done to evaluate evidence on the comparative effectiveness of surgery
versus SIJIs for injection confirmed non-traumatic SIJ 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 VAS or NRS 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 SIJIs.46 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 1 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 SI region
pain exists, and intra-articular anesthetic blockade may underestimate the
true prevalence of SI 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=0.025). 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=0.037).48 Limitations include study design, self-reported patient
outcomes, and short follow up.

In a single blinded randomized trial by Visser 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 SIJs 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 conclude 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 RCT comparing patients with SIJ 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 SIJ 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. SR 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 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 SLBBs 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 SLBBs were evaluated in asymptomatic
volunteers. Seventy percent of the active group achieved loss of sensation
within the IO and dorsal SI 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.
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 SLBBs 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. And
while studies have shown some predictive value of diagnostic intra-articular
blocks variations in patient selection, criteria for positive SIJ block, RFA
technique and assessment tools are highly variable limiting the ability to
produce reliable MA and confirmatory results in the current literature.

Several different techniques for RF neurotomy including monopolar, bipolar,
cooled and palisade (strip) lesions have been utilized. There is not
sufficient evidence to state 1 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 SIJs. A different procedure called cryoanalgesia has been
proposed for SIJ pain. There is minimal literature on the role of
cryoanalgesia for SIJ pain and the SMEs agree there is not sufficient evidence
to support cryoanalgesia of SIJ.

_RCTs with Placebo Arm_

Our SME reported 5 sham-controlled studies regarding the efficacy of SIJ
RFA.52-55 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. MA 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 SIJ denervation is a viable treatment for patients with chronic,
intractable SIJ pain. Participants included 28 patients with injection
diagnosed SIJ pain using 75% or greater improvement after a single diagnostic
SIJI. Under local anesthetic block, 14 patients received L4-L5 primary dorsal
rami and S1-S3 lateral branch RF 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%) RF-treated patients experienced pain
relief of 50% or greater measured by Numeric Rating Score (NRS) and
significant functional improvement measured by 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 RF 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 SIJ 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 (LBN) and 17 to sham
procedure. At 3 months subjects in the placebo group were allowed to crossover
and 16/17 subjects preceded with LBN. 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 LBN 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 11.9.56

van Tilburg 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 RFA 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 2 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 RF 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 17 reporting improvement.56 Eleven subjects were treated with the
RFA 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 1 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 LBP 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 SIJ trial.58 Diagnosis was made by history and physical exam and 1
diagnostic injection with 50% improvement in pain. Of 110 subjects who
received sacral nerve radiofrequency ablation (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
RFA 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 the 1 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 1 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 3 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.56 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 months 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**

**Summary of findings:**  
  
---  
  
**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 low52,53,56,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)

|



Low53

|

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

  1. Risk of Bias downgrade due to detection bias (blinding), incomplete outcomes data. 
  2. Indirectness due to differences in interventions.
  3. 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 RFA procedures for SIJ 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 MA to compare the clinical effectiveness of RF
neurotomy versus conservative nonsurgical approaches for the management of
chronic lumbar and SIJ pain. Five of 15 studies included reported SIJ pain
with the rest on lumbar facet joint pain. In the pooled data authors conclude
patients treated with RF 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 SLBRFA 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 SLB, 24/32 studies included the L5
dorsal ramis, and all studies included the S1 to S3 SLBs except for 2.31 Most
studies were observational and uncontrolled and only 2 placebo-controlled
trials were available. The type of RFA 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 RF neurotomy is level II-III. The evidence for
conventional RF 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 SLBBs and the
effectiveness of SLB thermal RF neurotomy for SI 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 SLB thermal RF neurotomy; however, evidence shows relief is
limited in extent and duration and the indication for the procedure is 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 SLB pain.
While this SR utilized GRADE criteria, the only included RCT accessing the
validity of SLBBs was challenged by small sample size with only 20 patients
enrolled (10 in active arm) and did not evaluate the role of SLBBs in
predicting SLBRFA success.

In a 2010 MA 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 SIJ pain at 3
months and 6 months. This was limited by lack of RCTs, 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 RFA included 240 subjects from retrospective,
observational and 2 small RCTs.1 Due to pooling of studies with different
designs, high heterogenicity and small samples sizes the results may not be
valid. 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 SR with MA designed to compare different RFA techniques used for
treatment of lumbar facet joint and SIJ pain was conducted. A MA 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
RFA, thermal RF and pulsed RF results in improvement for lumbar facet joint
and SIJ pain for up to 6 months. However, the authors acknowledge that a
comparison of the efficacy among 3 RF techniques in the treatment of LBP 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 SR pairing thermal versus cooled RFA in patients with SIJ pain included
9 studies with a total of 276 patients. The MA 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 MA 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 2 techniques examined and the literature is
currently lacking calling for additional studies period.65 This MA is limited
by pooling data from multiple study types and very high heterogenicity. While
MA 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
MA 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. MA 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.

_RCTs with comparative arm (non-placebo)_

A randomized blinded study with 30 patients with chronic LBP requiring regular
analgesia and single positive diagnostic SIJ block requiring 75% or greater
pain relief.67 Fifteen underwent RF 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 1 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
1 month (3.333  0.4880) post-procedure with increase at 3 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 6 months, 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 RF with
SIJ block compared SIJI to bipolar thermal RF.70 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 3 groups (n=20 in each group):
ultrasound guided SIJI with local anesthetic/corticosteroid, conventional or
modified (needle distance >1cm) bipolar RF ''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<0.001). 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<0.001). 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 SIJ. 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
SIJ 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 LBN of S1-S3 and L5 dorsal rami to
treat chronic SIJ-mediated LBP. 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 3 points on NRS.
The authors conclude cooled RF denervation shows long term efficacy for up to
2 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 RFA 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 RFA and 9
months after repeat RFA with the longest duration of pain relief has 26
months.76 Both studies are limited by the study design without any placebo-
controlled or sham controlled group, no comparison to conventional RFA, 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 SIJ pain and confirmed with single positive diagnostic intraarticular
SIJI underwent conventional RFA. Authors report an overall decrease in mean
NRS pain score decreasing from 7.7  1.8 at baseline to 2.8  1.2 at 1 month
and to 3.1  1.9 at 6 months post-procedure (p<0.001) with 27/32 reporting
satisfaction. Long-term pain relief was sustained at 12- and 18-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 RFA 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 RFA. The authors report a decrease in NRS 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**

SIJ 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 AS 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 1 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 SIJIs. SMEs 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 period 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 SIJIs
recommendation of 50% relief for 3 months.22 The QALY for SIJ 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 SMEs 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 1 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 SIJIs, intra-articular needle placement was
confirmed on subsequent 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. 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 SIJIs, 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. 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 Anesthesiologists 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 SIJIs. 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 RFA.10

The SME 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 LBP 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 SIJI 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 RFA of the SLB 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 SIJIs & RFA5:_

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

  1.     1. Patient's report of non-radicular, typically unilateral, pain that is maximal below the L5 vertebrae, localized over the posterior SIJ, and consistent with SIJ pain.
    2. A physical examination typically demonstrating localized tenderness with palpation over the sacral sulcus (Fortin's point, i.e., 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.
    3. Positive response to a cluster of at least 3 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 IO ligaments and aid in the diagnostic work-up of LBP. 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 2 separate occasions.
  * Therapeutic injections:

Image-guided intra-articular SIJIs of corticosteroid with or without local
anesthetic are indicated for the treatment of SI pain when = 1 of the listed
criteria are met:

  1.     1. Clinical criteria for diagnostic SIJI 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.
    2. SIJ pain has been confirmed with diagnostic intra-articular SIJIs.

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

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

    5. Patients with spondyloarthropathies such as AS.

  * RF neurotomy:

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

  1.     1. 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.

    2. Posterior SI ligament complex pain has recurred after = 50% improvement for  6 months from prior RF 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 SI 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 RF neurotomy of the lateral branches of the sacral dorsal rami most of the studies selected were based on their response to intra-articular SIJIs rather than diagnostic blocks of the SLBs 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 SIJI, 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 SIJIs 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 SI 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 SI 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 SIJ interventions, the evidence for cooled RF neurotomy is fair; limited for intra-articular injections and periarticular injections; and limited for both pulsed RF and conventional RF 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 3 RCTs comparing injection to RFA 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 RCTs 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 1 to 2 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 RF 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 SIJIs with the intra articular approach were performed using a 50% or greater reduction in pain prior to advancing to RF.

The literature for SIJ 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 SIJIs 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 3 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 SIJIs.
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 2. 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 SIJIs is not standard.22,74 Bilateral administration, while
may be appropriate in some cases, is also not standard.

Multiple guidelines, SME input and 1 paper suggest that intra-articular
injections may not be optimal for selection for RFA. Because RFA focuses on
the posterior nerves, they recommend lateral sacral branch blocks (targeting
dorsal and IO 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
SMEs on our panel support this as a treatment option. While MA that have been
done in attempt to reconcile the small sample size, extremely high
heterogenicity in these studies is problematic. Some MA 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 a small sample size (n=79).60
There are no studies to determine if 1 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 bene?t 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.