Clinical outcome of instrumented fusion for the treatment of failed back surgery syndrome: a case series of 100 patients.

Abstract

Failed back surgery syndrome is defined as persistent chronic low-back pain and/or leg pain lasting more than 1 year, despite of one or more surgical procedures. Instrumented spinal fusion has been offered by surgeons as a potential treatment to recover from pain and functional disability. Factors contributing to good outcome of instrumented spinal fusion have not been investigated extensively. This study evaluated the global perceived recovery and functional status of patients after instrumented fusion for the treatment of failed back surgery syndrome.
Between January 2004 and September 2007, 100 patients underwent instrumented spinal fusion because of persistent back and/or leg pain lasting more than 1 year despite of one or more previous spine surgeries. The global perceived recovery of the patients was documented on a seven-point Likert scale, in which good outcome was defined as "complete recovery" and "almost complete recovery". Pain was evaluated by the 100-mm visual analogue scale (VAS) of back pain and leg pain, and functional disability measured by the Roland Disability Questionnaire for Sciatica (RDQ) and Oswestry Disability Index (ODI). The Hospital Anxiety and Depression Scale (HADS) evaluated psychological co-morbidity. All patients were sent questionnaires by mail. Pearson's correlation coefficient was calculated between outcome measures and preoperative patient characteristics.
Eighty-two patients (82% response rate) returned questionnaires that were useful for analysis. After a mean follow-up period of 15 months, 35% of the patients reported good outcome, whereas 65% had unsatisfactory outcome. The mean (± SD) score of VAS low-back pain and leg pain was 45.7 ± 29 and 37.9 ± 31.9, respectively. The mean (± SD) RDQ and ODI score was 11.8 ± 5.4 and 30.6 ± 20.3, respectively. HADS score indicated a possible anxiety disorder in 28% of the patients and in 30% a possible underlying depression. Of the patients' baseline characteristics, there was only a significantly negative correlation between level of education and outcome.
The present study showed disappointing outcome of instrumented fusion for the treatment of failed back surgery syndrome in terms of perceived recovery, functional disability and pain. Conservative management is probably more beneficial and, therefore, more selective and careful assessment should be done in order to prevent unnecessary surgery.

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CLINICAL ARTICLE
Clinical outcome of instrumented fusion for the treatment
of failed back surgery syndrome: a case series of 100 patients
Mark P. Arts & Nicola I. Kols &
Suzanne M. Onderwater & Wilco C. Peul
Received: 29 February 2012 /Accepted: 1 May 2012 /Published online: 16 May 2012
#The Author(s) 2012. This article is published with open access at Springerlink.com
Abstract
Object Failed back surgery syndrome is defined as persis-
tent chronic low-back pain and/or leg pain lasting more than
1 year, despite of one or more surgical procedures. Instru-
mented spinal fusion has been offered by surgeons as a
potential treatment to recover from pain and functional
disability. Factors contributing to good outcome of instru-
mented spinal fusion have not been investigated extensively.
This study evaluated the global perceived recovery and
functional status of patients after instrumented fusion for
the treatment of failed back surgery syndrome.
Methods Between January 2004 and September 2007, 100
patients underwent instrumented spinal fusion because of
persistent back and/or leg pain lasting more than 1 year
despite of one or more previous spine surgeries. The global
perceived recovery of the patients was documented on a
seven-point Likert scale, in which good outcome was de-
fined as “complete recovery” and “almost complete recov-
ery”. Pain was evaluated by the 100-mm visual analogue
scale (VAS) of back pain and leg pain, and functional
disability measured by the Roland Disability Questionnaire
for Sciatica (RDQ) and Oswestry Disability Index (ODI).
The Hospital Anxiety and Depression Scale (HADS) eval-
uated psychological co-morbidity. All patients were sent
questionnaires by mail. Pearson’s correlation coefficient
was calculated between outcome measures and preoperative
patient characteristics.
Results Eighty-two patients (82% response rate) returned
questionnaires that were useful for analysis. After a mean
follow-up period of 15 months, 35% of the patients reported
good outcome, whereas 65% had unsatisfactory outcome.
The mean (± SD) score of VAS low-back pain and leg pain
was 45.7±29 and 37.9±31.9, respectively. The mean (± SD)
RDQ and ODI score was 11.8±5.4 and 30.6±20.3, respec-
tively. HADS score indicated a possible anxiety disorder in
28% of the patients and in 30% a possible underlying
depression. Of the patients’ baseline characteristics, there
was only a significantly negative correlation between level
of education and outcome.
Conclusions The present study showed disappointing out-
come of instrumented fusion for the treatment of failed back
surgery syndrome in terms of perceived recovery, functional
disability and pain. Conservative management is probably
more beneficial and, therefore, more selective and careful
assessment should be done in order to prevent unnecessary
surgery.
Keywords Failedbacksurgerysyndrome.Instrumented
fusion.Pain.Postlaminectomysyndrome.Surgery
Introduction
Failed back surgery syndrome (FBSS), also known as
post-laminectomy syndrome, is defined as persistent
low-back pain and/or leg pain lasting more than 1 year
despite one or more surgical procedures. Nearly 20% of
the patients undergoing spine surgery will require sec-
ondary surgery for persistent pain or surgery related
complications during the subsequent years [9]. Success
rates have been reported to drop to 30% after a second
spine surgery, 15% after the third surgery, and approx-
imately 5% after the fourth surgical intervention [7].
Multiple factors can contribute to the development of
FBSS. Surgery-related factors may be wrong surgical
M. P. Arts (*):N. I. Kols:S. M. Onderwater:W. C. Peul
Department of Neurosurgery, Medical Centre Haaglanden,
PO Box 432, 2501 CK, The Hague, The Netherlands
e-mail: m.arts@mchaaglanden.nl
Acta Neurochir (2012) 154:1213–1217
DOI 10.1007/s00701-012-1380-7

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technique, surgical complications, instability, recurrent
disc herniation, and fibrosis-associated neuropathic pain.
Age, lifestyle (i.e. smoking, obesity, lack of physical
exercise) and psychosocial factors, such as depression,
anxiety and insomnia, are possible patient-related char-
acteristics. All of these factors may negatively influence
the results of instrumented spinal fusion [4,6,12,14–16].
The “gold standard” in the treatment of FBSS is con-
servative management by pain control and cognitive
behavioural therapy, although some FBSS patients may
benefit from instrumented spinal fusion [4,5,7,15]. Care-
ful assessment by anamnesis, medical history, physical
examination, and additional screening tools is crucial to
identify possible physical causes of FBSS. Apt patient
selection may therefore lead to improved surgical out-
come [1–5].
Previous studies regarding clinical outcome of instru-
mented spinal fusion in patients with FBSS, have not fo-
cused on possible associations between outcome and
predefined influencing factors [5]. In the present case series
of 100 patients with FBSS who underwent instrumented
spinal fusion, associations between patient characteristics
and outcome were evaluated.
Methods
Study design and patient population
The study was performed as a retrospective case series. All
patients who had undergone instrumented spinal fusion
between January 2004 and September 2007 were selected
from the hospital electronic patient system (487 patients).
Inclusion criteria were instrumented lumbosacral spinal fu-
sion, one or more previous lumbosacral spine surgeries, and
chronic low-back pain with or without leg pain, lasting more
than 1 year after the index surgery (Table 1). Pain was
refractory to conventional pain medication, although adhe-
siolysis, spinal cord stimulation (SCS) or epiduroscopy was
not performed. From the 487 patients, 100 patients fulfilled
the criteria (49 men and 51 women, mean age 54.2 years).
Patients’ baseline characteristics are listed in Table 2. All
patients underwent pedicle screw fixation with interbody
fusion at one level (58 patients), two levels (28 patients),
or three or more levels (14 patients). All procedures were
performed in Medical Centre Haaglanden by the first and
last author (MA and WP).
Outcome measures
The primary outcome measure was the dichotomised Likert
score in good recovery (“complete recovery” and “almost
complete recovery”) and bad recovery (“little recovery” to
“worse than ever”). Secondary outcome measures were the
postoperative scores of the visual analogue scale (VAS) of
low-back pain (0-100 mm) and VAS leg pain (0-100 mm).
Functional assessment was documented by the illness-
specific Roland Disability Questionnaire for Sciatica
(RDQ) (0–23 with higher scores indicating worse functional
status) and Oswestry Disability Index (ODI) (0–100 with
higher index indicating worse disability). Assessment of
anxiety or depression was documented by the Hospital
Anxiety and Depression Scale (HADS). The HADS consists
of a seven-item depression scale and a seven-item anxiety
scale. The score ranges from 0–21 with a high score being
indicative for depression/anxiety. The outcomes were
assessed by a written questionnaire sent by mail.
Data analysis
All statistical analyses were performed by SPSS version
17.0 for Windows. Per included patient, the RDQ, ODI,
HADS-anxiety and HADS-depression scores were calculat-
ed. Pearson’s correlation coefficients were calculated to
analyse the association between the different outcome meas-
ures and preoperative patient characteristics (gender, level of
education, age at surgery, body mass index, smoking status,
number of previous surgeries and number of spinal levels
fused). All statistical analyses had a statistical threshold of
p00.05.
Results
Of the 100 questionnaires sent by mail, two respondents had
only filled in remarks on the questionnaire and 16 patients
were lost to follow-up despite several attempts of telephone
and mail contact. These 18 patients were excluded from
Table 1 Inclusion and exclu-
sion criteria
Inclusion criteriaExclusion criteria
Instrumented lumbar or lumbosacral fusionInstrumented cervical or thoracic
fusion
Surgery for spinal tumours
Surgery for spinal trauma
History of ≥ 1 lumbosacral spine surgery
Chronic low-back pain, with or without leg pain, lasting ≥1 year after
index surgery
1214Acta Neurochir (2012) 154:1213–1217

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analysis. The mean follow-up was 14.7 months (min.
2 months, max. 45 months). Of the responding 82 patients,
35% documented good recovery and 65% perceived no
difference or worsening. The mean (± SD) score of VAS
back pain and leg pain was 45.7±29.6 and 37.9±31.9,
respectively. Functional disability measured by RDQ and
ODI was 11.8±5.4 and 30.6±20.3, respectively. Assessment
of the HADS documented that 28% had symptoms befitting
an underlying anxiety disorder, and 30% showed symptoms
related to an underlying depression (HADS scores≥8)
(Table 3). A significantly negative correlation was only
found between patients’ perceived recovery and level of
education (R0−0.228; p<0.05). Other correlations between
perceived recovery and preoperative characteristics could
not be found
Discussion
The present study shows that the outcome of instrumented
spinal fusion in patients with FBSS is disappointing; only
35% of the patients reported good outcome, whereas in 65%
the symptoms were unchanged or worse. Assessment of
postoperative pain and functional disability showed that
the majority of the respondents experienced moderate to
severe pain and functional disability following spinal fusion.
In addition, nearly one-third of the respondents had an
indication of an anxiety or depression disorder, which cor-
related with predominantly back pain and functional
disability.
The number of patients with FBSS is increasing as more
spine surgeries are being performed and many are not suc-
cessful. Preoperative counselling on patient expectations
and surgical success are vital to achieve a realistic goal for
both surgeon and patient. Since multiple factors may con-
tribute to the development of FBSS, it is of utmost impor-
tance to carefully assess the patient’s history and medical
records of the previous surgeries on psychological risk
factors, previous treatment regimes for chronic pain,
Table 2 Demographic data of 100 patients with FBSS
Baseline characteristicsNo.
Sex
Male
Female
Level of education
Basic vocational education
Secondary vocational education
Higher vocational education
Other
Missing
Work capability
Normal
Moderate
Nearly incapable
Completely incapable
NA
Missing
Smoking
Mean Body Mass Index (SD)
Mean age at surgery in years (SD)
Etiology of FBSS
Previous discectomy
Previous laminectomy
Adjacent level disease after instrumented fusion
Instability
Other
No. of previous surgeries
1
2
3
4
5
49
51
29
28
21
3
20
6
13
2
21
40
18
35
26.8 (4.2)
54.2 (12.0)
41
18
21
15
5
59
20
12
7
2
NA not applicable, SD standard deviation
Table 3 Postoperative
assessment of outcome
measures of 82
respondents with FBBS
Outcome measure No. (%)
Likert
Good recovery
Bad recovery
Mean VAS low-back pain
(mm)
VAS low-back pain
< 40 mm
≥ 40 mm
Mean VAS leg pain (mm)
29 (35)
43 (65)
45.7±
29.6
33 (40)
49 (60)
37.9±
31.9
VAS leg pain
< 40
≥ 40
Mean RDQ
RDQ<8
RDQ≥8
Mean ODI (%)
46 (56)
36 (44)
11.8±5.4
17 (21)
65 (79)
30.6±
20.3
29 (35)
53 (65)
ODI<25% disability
ODI≥25% disability
HADS anxiety
< 8
≥ 8
HADS depression
< 8
≥ 8
59 (72)
23 (28)
57 (70)
25 (30)
Acta Neurochir (2012) 154:1213–12171215

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significant pathology not addressed during earlier consulta-
tions, and incorrect diagnosis. Psychological risk factors
need attention prior to and directly after surgery but should
not exclude a patient with a clear indication for surgery.
Possible biomechanical causes of persistent pain, such as
poor posture, pes planus, and leg-length difference may also
contribute to chronic low-back pain [13].
Inappropriate surgical technique of the index opera-
tion may result in spinal instability or adjacent-level
disease several years later. According to a retrospective
study, the incidence of spinal instability will increase
from 12% after one surgery, to 50% after four or more
revision surgeries [7]. Exploration at the wrong level, as
well as surgeon’s inability to achieve the surgical goal,
may result in persisting pain. Progression of degenera-
tive disease at the index level or adjacent level, such as
imbalanced weight distribution on the facet joints, may
cause further stenosis and pain. In addition, surgical
complications may arise and can involve cerebrospinal
fluid leakage, wound infection, nerve root injury, epidu-
ral hematomas, arachnoiditis, pseudomeningocele and
battered root syndrome [3]. Evaluating these features
should improve patient selection for spinal fusion or
alternative treatment options.
Currently, the gold standard in the treatment of FBSS
involves conservative management. Pharmacological treat-
ment, such as antidepressants, NSAIDs, COX-2 inhibitors,
tramadol, opioids, muscle relaxants and gabapentinoids, is
prescribed to reduce pain and facilitate physical activity.
When conservative management fails, pain intervention
such as medial branch block, epidural steroids, percutaneous
epidural adhesiolysis, intrathecal drug administration, and
spinal cord stimulation (SCS) need to be evaluated. Prefer-
ably, these approaches should be discussed by an interdis-
ciplinary management team [3].
Evidence-based guidelines on various treatment regimes
of patients with FBSS are lacking since high-quality
randomised controlled trials on this topic are scarce.
Brox et al. [2] compared the effectiveness of lumbar
fusion with cognitive intervention and exercise in 60
patients. Both groups reported 50% success rates and
lumbar fusion did not show any superiority. Kumar et
al. [8] randomised 100 patients with FBSS in conven-
tional pain medication management with or without
spinal cord stimulation. Patients treated with additional
SCS reported better pain relief, functional ability and
patient satisfaction. However, due to the large number
of crossovers, the results should be interpreted carefully.
North et al. [11] randomised 50 patients with FBSS in
reoperation and SCS. Similarly, it was found that sig-
nificantly more patients from the reoperation group
crossed over to the SCS group. Patient satisfaction and
pain control were significantly higher in the SCS group,
both randomised and crossover, making SCS more suc-
cessful than reoperation. In general, revision surgery
should be evaluated carefully, as the overall success rate
in patients with FBSS following previous spine surgery
is low and declining with each subsequent procedure.
Follow-up rates up to 5 years documented a good
outcome between 19% and 34%, where success was
defined by the criterion of at least 50% pain relief
[10,11]. The decision to proceed with additional revi-
sion surgery, however, was based on the surgeon’s as-
sessment of the patient.
Regarding demographic data and outcome in patients
with FBSS, it is shown that female gender, higher age,
obesity, number of spine surgeries, multiple fused spinal
levels, smoking status and high usage of analgesics nega-
tively influence experienced recovery [1,4,6,12,14–16].
Aside from a negative association between perceived recov-
ery and the level of education, no significant relation be-
tween perceived recovery and functional disability and
baseline characteristics was found in the present study. Our
findings are in agreement with the socio-demographical
findings reported by the Swedish Lumbar Spine Study, in
which influence of personality traits on surgical outcome
was investigated. It was shown that patients with neurotic
personality, having overlapping characteristics with the dys-
functional personality type, is predictable for an unfavoura-
ble outcome and could possibly benefit more from
conservative treatment [9]. The relation between outcome
and a possible underlying anxiety disorder or depression
showed a negative correlation between perceived recovery
and functional disability. Notably, a possible underlying
depression and the amount of back pain and functional
disability assessed by the RDQ showed an association indi-
cating a predictive value for HADS depression, back pain
and functional disability. However, based on a single post-
operative measurement, no conclusive statements can be
made regarding the predictive value of these patient charac-
teristics. Further studies are needed to evaluate the correla-
tion between possible psychiatric co-morbidity and outcome
measures.
The present results have several limitations. Firstly, the
study is conducted as a single-centre retrospective cohort
with limited follow-up moments. Secondly, there is no
available data on co-morbidity like osteoporosis, arthritis
or polyneuropathy that may have influenced the outcome.
Moreover, there is no routine radiographic examination
focusing on fusion status, although the relationship between
fusion and outcome is debatable [5]. Finally, based on
clinical expertise during the course of the cohort, selection
bias may have played a role since latter patients may have
been evaluated more critically. Future randomised con-
trolled trials on patients with FBSS are needed in order to
define the best treatment strategy.
1216Acta Neurochir (2012) 154:1213–1217

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Conclusions
The present study shows disappointing results in patientswith
FBSS treated with instrumented spinal fusion. Surgical can-
didates should be assessed and selected more carefully in
order to prevent unnecessary surgery. Therefore, conservative
pain management, behavioural therapy, and SCS is probably
more beneficial in the majority of patients with FBSS.
Disclosure
materials or methods used in this study or the findings specified in this
paper.
The authors report no conflict of interest concerning the
Conflict of interest
None.
Open Access
tive Commons Attribution License which permits any use, distribution,
and reproduction in any medium, provided the original author(s) and
the source are credited.
This article is distributed under the terms of the Crea-
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