**Definitions and Scope**

This local coverage determination (LCD) discusses fusions of the lumbar spine.

**Background**

This LCD will discuss indications for surgical fusion of the lumbar spine.
Total disc arthroplasty is not covered by this LCD.

**Requirements**

Lumbar fusion must be performed by a qualified surgeon in an operating room
with the necessary equipment. For elective surgeries, providers should verify
that the necessary equipment and hardware to perform the procedure on a
patient is available prior to the induction of anesthesia.

Documentation must demonstrate that the patient met at least 1 of the
indications for the procedure as described below. Where possible, there must
be documented shared decision making with the patient or the individual who is
serving as the proxy decision maker for the patient with the appropriate
discussion of anticipated risks and benefits of the procedure.

**Indications for lumbar fusion include any of  the following.**

A patient must have at least 1 of the following:

1\. Radiographic or clinical evidence of instability due to any 1 of the
following:

     a. Congenital deformities,

     b. Trauma,

     c. Fractures,

     d. Chronic degenerative conditions,

     e. Tumor,

     f. Infection,

     g. Erosive conditions,

     h. Space-occupying lesions, **or**

     i. Iatrogenic causes, including expected instability as a consequence of another medically necessary spine procedure.

      If more than 1 level is fused under this indication, the record must reflect that each fused level is affected by 1 of the above conditions.

 2\. Symptomatic spinal deformity (in the absence of instability or neural
compression) which meets the following criteria:

     Both of the first 2 criteria must be met:

     a. Functional limitation in daily activities due to back pain or discomfort **_and_**

     b. Nonresponse to at least 1 year of non-operative treatment

     Any 1 of these 3 criteria must be met:

     c. Sagittal or coronal imbalance by at least 5 cm as measured on radiographic imaging of the entire spine, **_or_**

     d. Progression of deformity by at least 10 degrees, **_or_**

     e. Scoliotic curvature of greater than 30 degrees

 3\. Revision surgery for pseudarthrosis following an initial spine surgery if
the following conditions are all met.

     a. The patient had a period of reduced pain initially following surgery **_and_**

     b. The time since the prior surgery has been at least 1 year **_and_**

     c. There is clear radiographic evidence of pseudarthrosis   ** _and_**

     d. The patient has exhausted available conservative treatment measures

The medical record must clearly reflect which conservative treatments the
patient has tried or is not a candidate for and why, including medical
therapies, physical and exercise therapies and injections. Outcomes for fusion
in revision surgery, usually do not lead to pain relief and as such fusion is
considered a last resort treatment option only when all other treatment
options have failed. This information must be communicated to the patient
prior to surgery to allow for appropriate shared decision making with a well-
informed patient. The medical record must reflect that this counseling was
done and that the patient wished to undergo surgery with the appropriately
informed consent.

 4\. Symptomatic compression of neural elements for which disc excision is
necessary for decompression. The record must reflect disc compression of
neural elements for each level fused based on this indication.

**Background**

Lower back pain is a common condition in the United States (Deyo, 2002 and
Freburger, 2009), which may be isolated to the lower back or radiate to the
lower extremities and may involve musculoskeletal structures or nervous
structures as well. Recommended initial treatment for chronic lower back pain
in most patients is based on an approach starting with self-care (Chou, 2007)
and adding more aggressive interventions to include rehabilitation,
medications, injections and even surgery in some patients (Chou, 2009).

A number of techniques for surgical fusion of the lumbar spine have been
developed, generally classified as interbody fusions or posterolateral fusions
(Mummaneni, 2014). There are numerous directional approaches to interbody
fusion, including anterior, posterior, lateral and transforaminal approaches,
with no clearly demonstrated superiority of one over the rest and as such the
best approach is usually a function of patient-specific factors and surgeon
comfort (Mobbs, 2015).

**Outcome Measurement**

Severity of lower back pain and response to treatment can be measured a large
number of ways including on a pain scale or using a scale that assesses the
ability of a patient to engage in life activities such as the Medical Outcomes
Study (MOS) Short Form 36 (SF-36) or Oswestry Disability Index (ODI). Among
the many back pain outcome measures available, the ODI is 1 of the most widely
used in both research and clinical practice and this particular outcome
measure has been recommended for use in clinical practice as an outcome
measure for the spine by the American Academy of Orthopedic Surgeons.
Moreover, this particular outcome measure has been selected for use in nearly
all of the high quality research examining lumbar fusion that was found in the
development of this LCD. An important question regarding any outcome measure
is: What is the clinical importance of given change in the outcome measure?
For the ODI in particular, a 10 point difference is considered the minimum
clinically important difference for improvement (Hagg, 2003). However, a 10
point improvement is significantly below the 26 improvement that has been
identified to correspond to a global improvement of "much better" in surgical
outcome evaluation (Hagg, 2003).

**Low back pain without neurologic compromise or radiculopathy**

A number of randomized trials have been performed to examine the potential
benefits of lumbar spinal fusion in patients with primarily axial low back
pain.

One of the earliest large randomized trials of lumbar fusion in patients with
low back pain was a study from Sweden in which 294 patients aged 25-65 with at
least 2 years of low back pain with radicular pain were randomized to 1 of 3
surgical techniques versus conservative treatment based on physical
rehabilitation (Fritzell, 2001). There was not a single primary outcome but
rather numerous primary outcome measures including: pain, disability, global
self-rating by the patient and back-to-work. Several scales were used, 1 of
which was the ODI. The investigators found a statistically and clinically
significant difference in all 4 primary outcome measures. There were
complications in 17% of the patients randomized in the surgical group and no
complications identified in the group managed conservatively.

A study of 349 patients aged 18-55 compared surgical spine stabilization to a
rehabilitation program (Fairbank, 2005). The surgical technique was at the
discretion of the surgeon. The primary outcome measure was ODI score after 2
years. The surgical group had a change in ODI score from 46.5 to 34.0 and the
rehabilitation group had a change in ODI from 44.8 to 36.1. This change
reached statistical significance but the investigators noted that this
difference was "marginal," and notably it is well below the minimum clinically
important difference identified by Hagg (2003). There were also 19
complications in the surgery group, 11 of whom required re-operation. There
were no specific complications identified related to rehabilitation in the
conservatively managed arm.

A research report merging data from 2 randomized controlled clinical trials in
Norway (Brox, 2010) compared instrumented posterolateral fusion with cognitive
intervention and exercises in 124 patients. Patients included had at least 1
year of low back pain and they were excluded if they had evidence of
neurologic compromise or radicular symptoms. The primary outcome was the ODI.
There was no difference in outcomes between the 2 groups 4 years later in
either the intention-to-treat or the as-treated analyses.

A systematic review of comparative and non-comparative studies examining the
effect of surgical fusion in axial low back pain (Phillips, 2013) concluded
that fusion surgery is supported by the literature as a treatment option in
refractory low back pain. A guideline from the Congress of Neurological
Surgeons has concluded that fusion or intensive rehabilitation may be
appropriate treatment options in patients who have not responded to
conventional conservative management (Eck, 2014). The North American Spine
Society has published a guideline that suggests spinal fusion may be an
appropriate treatment option in patients with refractory axial low back pain
due to single level degenerative disc disease who have no psychiatric
comorbidities and are not currently smoking (North American Spine Society,
2014).

**Low back pain with spinal stenosis or radicular symptoms**

Surgical treatment of patients with low back pain and symptoms of nerve root
involvement has been studied with both observational and randomized controlled
trials with the highest quality evidence in the treatment of chronically
painful conditions without spinal instability or evidence of neurologic
compromise.

Prior to the publication of the Maine Lumbar Spine Study, there was a paucity
of outcomes data from large studies in the United States comparing surgical to
non-surgical management of back pain with nerve root involvement. The Maine
Lumbar Spine Study was an observational study that followed patients treated
in community orthopedic and neurosurgical practices evaluated and treated for
spinal stenosis (Atlas, 2005 A) or radiculopathy (Atlas, 2005 B) with either
surgical or non-surgical techniques. Outcomes as far as 8-10 years post-
operatively were assessed. This study suggested that surgical treatment may
have a role in the management of these 2 conditions but the initial surgical
treatment in these studies generally did not involve a spinal fusion.

To date the largest and highest quality research on the effects of lumbar
spine surgery has come from the Spine Patients Outcome Research Trial (SPORT)
project (Birkmeyer, 2002). This group of studies involved 13 clinical centers
and was specifically designed to study the effects of lumbar spine surgery in
the groups it was most commonly being used at the time of study design to help
address some of the controversies surrounding spine surgery that arose in part
based limitations of prior studies. The SPORT project also included an
observational study to evaluate outcomes of patients who decline participation
in 1 of the randomized trials. Some of the SPORT outcomes have been assessed
as far as 8 years out. The SPORT project contained 3 multi-center randomized
controlled trials evaluating surgical treatment in patients with
intervertebral disc herniation (IDH), degenerative spondylolisthesis (DS) and
spinal stenosis (SS). Symptoms of nerve root involvement were required for
study enrollment and all patients had tried conservative management prior to
study enrollment. Conservative management was tried for at least 6 weeks in
the IDH group and for at least 12 weeks in the SS and DS groups.  Primary
outcome measures included the SF-36 and ODI.  Subjects who were enrolled and
randomized in the SPORT trials under the diagnosis of IDH or SS were
surgically treated with discectomy and decompressive laminectomy respectively.
Surgical fusion was not part of the planned treatment protocol in either
group. Patients who were enrolled in the SPORT trials and randomized for a
diagnosis of DS received a decompressive laminectomy and possibly a single
level fusion.

Patients whose outcomes were studied in the SPORT project following treatment
for IDH had failed 6 weeks of conservative management. There were 501
participants enrolled in the randomized study and 743 were enrolled in the
observational study. As noted above, surgical treatment consisted of
discectomy with fusion. In the randomized trial of IDH patients, there was no
statistically significant difference in the primary outcome measures at 3
months, 6, months or 2 years but a high degree of cross-over limited the
intention-to-treat analyses (Weinstein, 2006 A). In the observational cohort
of IDH patients, which was an as-treated analysis, patients managed surgically
had statistically significantly better primary outcomes at 3 and 6 months as
well as at 2 years (Weinstein, 2006 B). In the 4 year follow-up study the as-
treated analysis demonstrated persistently better outcomes in those treated
with surgery rather than conservatively (Weinstein, 2008 A).

Patients who were enrolled in the SPORT trials for SS following 12 weeks of
failed conservative treatment have been followed for at least 8 years and the
planned surgical treatment did not involve fusion but rather decompressive
laminectomy alone. A total of 289 patients were in enrolled in the randomized
trial and 365 were enrolled in the observational cohort. Intention to treat
analyses showed that the group who had surgery did significantly better on the
bodily pain component of the SF-36, but not on the physical functioning
component of the SF-36 or on the ODI at 2 years. As with the study of IDH
patients, there was a significant rate of cross-over in the randomized trial,
limiting the inferences that can be made from intention to treat analyses. In
the as-treated analysis of both randomized patients and patients in the
observational arm, patients treated surgically had significantly better
outcomes on the SF-36s bodily pain and physical functioning components as well
as on the ODI (Weinstein, 2008 B). Of the patients initially enrolled in the
trial- 188 of those enrolled in the randomized trial, 252 of those in the
observational cohort were available for follow-up at 4 years. The 4 year
follow-up data indicated persistence of the findings at 2 years (Weinstein,
2010). At 8 years, 159 of those in the randomized trial and 189 of those in
the observational cohort were followed-up. Subjects treated with surgery still
appeared to have better outcomes, though there was evidence of a convergence
of outcomes over time (Lurie, 2015).

Patients who failed 12 weeks of conservative management for degenerative
spondylolisthesis were eligible for this arm of the SPORT project. Surgical
treatment involved decompression with possible single level fusion. A total of
304 patients were enrolled in the randomized trial and 303 were enrolled in
the observational cohort. The intention-to-treat analysis of the randomized
trial showed no benefit at 1 or 2 years of surgery, though cross-over rates
were high. The as-treated analyses of both the randomized and the
observational groups showed better outcomes for surgery at 1 and 2 years on
both the SF-36 and ODI (Weinstein, 2007). Follow-up data collected at 4 years
demonstrated persistently better outcomes for the surgically treated patients
in as-treated analyses (Weinstein, 2009).

In the spondylolisthesis arm of the SPORT trial, the surgical procedure of
choice was laminectomy in addition to possible fusion, without an assessment
of laminectomy with vs without fusion in this population. The Spinal
Laminectomy versus Instrumented Pedicle Screw (SLIP) trial sought to address
the issue of whether fusion plus laminectomy is superior to laminectomy alone
in patients with spinal stenosis and spondylolisthesis (Ghogawala, 2016). This
was a randomized controlled trial in which 66 patients aged 50-80 years old
with stable degenerative spondylolisthesis with symptomatic lumbar SS were
randomized to undergo decompressive laminectomy alone versus decompressive
laminectomy with posterolateral instrumented fusion. The primary outcome
measure was SF-36 core after 2 years and ODI was a secondary outcome measure.
The group who underwent decompression and fusion had statistically
significantly better SF-36 scores at 2 years, a difference that was maintained
at 3 and 4 years following surgery. There was no significant difference in ODI
score changes for the 2 groups. The fusion group had greater operative blood
loss, time spent in the hospital and operative time. However, the rate of
reoperation was significantly less in the fusion group (14%) as compared with
the laminectomy alone group (34%).

The Swedish Spinal Stenosis Study was published at the same time as the SLIP
trial and also addressed the issue of whether fusion plus decompression is
superior to surgical decompression alone in patients within spinal stenosis
both with and without spondylolisthesis (Forsth, 2016). In this study 247
patients aged 50-80 years old with stenosis at 1 or 2 levels, of which 135 had
spondylolisthesis, were randomized to decompression alone (with technique left
to the surgeon) vs. decompression plus fusion. The primary outcome measure was
the ODI 2 years post-operatively.  There were no differences in ODI change at
2 years in either treatment group, with similar results for both patients with
and without pre-operative spondylotlisthesis. A 5 year follow-up of 153
patients also showed no difference between the 2 treatment groups.

Following the SLIP trial and the Swedish Spinal Stenosis Study, a pragmatic
observational study of outcomes in clinical practice intended to assess non-
inferiority of decompression alone as compared with decompression plus fusion
in patients with spinal stenosis and lumbar spondylolisthesis was published
(Austevoll, 2017). This study matched 260 patients who had decompression plus
fusion with 260 patients who had decompression alone. Primary outcome measures
included Numeric Rating Scale scores for leg and for back pain as well as ODI
at 3 and 12 months post-operatively.  The authors reported that they were
unable to conclude that decompression alone was non-inferior to decompression
plus fusion. However, the study results indicate that the only primary outcome
for which there was a statistically significant difference in the proportion
of patients achieving the pre-specified minimal clinically important
difference was Numeric Rating Scale back pain score.

Guidelines from the Congress of Neurological Surgeons indicate that there is a
lack of high quality evidence to support the benefit of fusion in addition to
laminectomy for patients who have spinal stenosis without spondylolisthesis
(Resnick, 2014 A). Additional guidelines from the Congress of Neurological
Surgeons developed prior to the publication of the SLP and Swedish Spinal
Stenosis studies indicate that fusion may be a reasonable addition to
decompression in patients who are getting surgical treatment for spinal
stenosis with spondylolisthesis (Resnick, 2014 B).

**Persistent Back Pain Following Previous Spine Surgery**

One of the largest studies to date examining the outcomes of surgical fusion
following an initial spinal surgery reviewed 100 cases of "failed back surgery
syndrome" (Arts, 2012). All patients had at least 1 year of persistent pain
refractory to conservative treatments after their initial spine surgery and
were treated with pedicle screw fixation and interbody fusion in the revision
surgery. Etiologies of failed back surgery syndrome specifically identified
included previous discectomy, previous laminectomy, adjacent level disease and
instability. The primary outcome measure was a dichotomous patient self-report
regarding recovery with options of "good recovery" or "bad recovery". Mean
follow-up time after revision surgery with fusion was 14.7 months. On the
primary outcome 35% of patients reported good recovery and the remaining 65%
reported bad recovery.

**Surgical treatment of other spinal conditions**

To date there are no large randomized controlled trials specifically regarding
the treatment of unstable spine morphologies, significant deformities,
neurologic compromise, spinal trauma, major spinal anatomic abnormalities,
infection, tumor or re-operation following an initial spine surgery. Spinal
fusion is currently often considered a necessary component of surgical
treatment for many of these patients based largely on observational studies
and consensus guidelines (Floman, 2008; Kotwal, 2011; Roussoly, 2010; Swan,
2006; North American Spine Society, 2014).

An observational study of 327 patients who underwent lumbar surgical
decompression and posterolateral lumbar fusion examined the relationship
between surgical indication and surgical outcomes (Glassman 2009). Operative
indications studied included spondylolisthesis, instability, stenosis,
scoliois, disc pathology or need for revision surgery due to nonunion,
adjacent level disease or post-discectomy revision. Multiple outcomes at 6
months, 1 year and 2 years were of interest including SF-36 score, ODI and
numeric rating scales for back and leg pain. For the full cohort, there was an
observed improvement in all outcomes but stratification of outcomes by
surgical indication revealed differences among the response to surgery. As
measured by ODI score change, improvements from greatest to smallest by
indication were as follows: spondylolisthesis, scoliosis, disc pathology,
postdiscectomy revision, instability, stenosis, adjacent level disease and
non-union from prior fusion. Revision surgery was needed in 10% of the entire
cohort with patients who were undergoing the index fusion as a revision
surgery having higher rates of revision of the index surgery.

Studies examining the role of surgical treatment in patients with low back
pain without evidence of nerve root involvement have been heterogeneous and
have shown a limited benefit of questionable clinical value for lumbar fusion
in a population of patients with chronic back pain. Guidelines from 2 major
societies recommend consideration of fusion in a select group of patients but
the North American Spine Society guideline acknowledged in the guideline text
that such a recommendation would be controversial. High quality research does
suggest that there is a measurable difference in improvement between patients
with degenerative disc disease who are treated with fusion versus those who
are treated conservatively. However, this measurable difference is small and
not clearly clinically meaningful, while the difference in adverse events is
clinically meaningful. Given the limited benefit that high quality research
has shown for fusion surgery for the treatment of low back pain, this A/B MAC
does not believe that evidence supports coverage for this indication.

A number of high quality studies provide evidence that lumbar decompressive
surgery provides a significant benefit in the reducing of symptoms due to
lumbar radiculopathy or spinal stenosis from multiple causes in patients who
have not improved with conservative management. Fusion in conjunction with
decompression has been well studied only in patients with lower extremity
symptoms attributable to the spine and spondylolisthesis. While there is high
quality evidence that fusion in conjunction with decompression provides clear
and meaningful improvements in pain and function as compared with conservative
management in patients with stable spondylolisthesis and symptomatic nerve
root involvement, it seems that most of the benefit of such a surgery comes
from the decompression component. Decompression plus fusion has little benefit
over decompression alone in this patient population when considering the
benefits and risks of both surgical approaches. While neurosurgical guidelines
consider the use of fusion reasonable in this patient population, these
guidelines were written prior to the publication of 2 high quality studies
which were designed to measure the efficacy of such an intervention in this
population and did not clearly find a meaningful benefit. This A/B MAC agrees
with voices in the spine surgery community (Greenway, 2016; Joaquim, 2016;
Peul, 2016) that the SLIP trial and Swedish Spinal Stenosis Study have
provided strong evidence that there is little if any benefit conferred by
adding surgical fusion to simple decompression in patients with stable or mild
spondylolisthesis and spinal stenosis.

Large randomized trials examining the effects of surgical fusion as compared
with treatment without fusion have not been done in patient populations with
spinal instability related to a fracture or unstable spondylolisthesis, major
spinal deformities, tumors, infection, neurologic compromise, trauma or
revision after an initial spine surgery. The nature of these conditions is
such that high quality research may be unfeasible or unethical. While there is
a paucity of high quality evidence for these conditions, there appears to be
little disagreement in the spine surgical community regarding the general
approach to appropriate management recommended in treatment guidelines. In
spite of the paucity of high quality evidence, these conditions likely warrant
treatment. As such this A/B MAC is basing coverage determination on low
quality research that is available.