Table 2
Review of the literature for key questions 3 and 4
1st author / year /
Intention-to-
Control for
Inclusion criteria
Surgical intervention
Comparison group
Randomization
FU
Participants
Precise description of
Symptom
Quantification of
Co–
(baseline)
symptoms(baseline)
duration
SL
treatment
Target variables
Relevant results
Indication of
study type / Period
treat analysis
bias / con-
performed?
founding (++,
sources /
+, –)
conflicts of
LoE
Our conclusion
2b
– Instrumented fusion +
Authors’ conclusion
funding
interest
Key question 3: Is instrumented fusion with decompression more successful in relation to pain and function than decompression alone in adult patients with degenerative SL and spinal canal stenosis?
Bridwell et al. /
– No
–
1993 / 2b cohort
– Surgery for degen. SL with
– Group I: decomp., n = 9
NC due to SPS
– Group II: decomp.
– Intended to be
– Min.
Group I: 7 fe-
– NC with leg pain and
+ posterolateral
randomized
2 y.,
male, 2 male
inability to walk distances
study / 1985–1990
fusion (autologous
[30]
iliac bone graft)
without instr., n = 10
– Group III: decomp.+
posterolateral fusion
– In fact, not all pts
– No data
– Unclear
– No data,
– Ability to walk
– Ability to walk distances
except:
distances
significantly:
average
3 y 2 mo
randomized
Group II: 6
Group 1:
– Progression of
Group I: 3/9 pts improved; 3/9
female, 4 male
no ortho-
SL
pts unchanged; 3/9 pts reduced
Yes
“For this specific class of pts, pedicle fixation
and fusion is indicated along with decomp.”;
decomp. better than de-
“Significantly more SL progression in groups I
comp alone
and II than in group III”
– Methodological short-
sis
– Preop. pathologic
Group III: 20
motion led to inclu-
female, 4 male
comings (no clear
Group II: 3/10 pts improved;
sion in group III
Mean age:
Group II +
5/10 pts unchanged; 2/10 pts
III: ortho-
reduced
randomization, different
baseline data, small cohorts)
sis
(autologous iliac
Group III: 20/24 pts improved;
bone graft) + pedicle
Group I: 72 yr
screw instr., n = 24
4 mo
– Poor study for answering
4/24 pts unchanged
key question
– Increase in SL:
Group II: 65 y
7 mo
Group I: 4/9 pts
Group III: 64 y
Group II: 7/10 pts
2 mo
Group III: 1/24 pts
– Of 12 pts whose SL progressed, one felt that surgery
was of benefit
– Of the other 31 pts, 28 felt
that surgery improved their
ability to walk distances
Ghogawala et al. /
– No
–
– Surgery for degen. SL1° +
– Decomp. alone, n = 20
– Decomp.+ poster-
2004 / 2b cohort
symptomatic lumbar SPS
olateral instr. fusion
study / 2000–2002
without gross instability
with pedicle screws,
[32]
iliac crest autograft,
– No previous spine surgery
n = 14
– No
1y
– Mean age 68.8
y
– Type of surgery
chosen by surgeon at
his discretion
at index level
– No data
– No data
– SL slip in mm
– No data
– ODI, SF-36
– Decomp. alone vs decomp. +
Yes
“Fusion was associated with greater functional
2b
improvement”
fusion at 1-y FU:
– Instrumented fusion +
decomp. better than de-
– No differentiation leg vs
– Preoperative
– Female 68%
back pain
extent of SL:
ODI: 27.4 (P=0.003) vs 14
– “No significant
– Symptomatic lumbar
8.5 mm
(P<0.001)
– Small cohorts
intergroup dif-
SPS
SF-36 PCS: 37.4 (P=0.005) vs
– Methodological short-
45.7 (P<0.001)
comings
Decomp. + fusion improved
– Type of surgery at the
better than decomp. alone in
surgeon’s discretion
ferences in the
preoperative
variables”
comp. alone
– Decomp. alone vs decomp. + fusion:
ODI: 41.0 vs 41.5
ODI (P=0.02) and SF-36 PCS
(P=0.003)
SF-36 PCS: 30.9 vs 29.8
– Older age: strong independent
predictor of poorer outcomes in
both groups (multivariate analyses; decomp. alone: ODI
P=0.028; SF-36 PCS P=0.008;
decomp. + fusion: ODI not
sign.; SF-36 PCS P=0.05)
Park et al. / 2012 /
case–control study
3b / 2005–2007
[33]
– No
–
– Degen. single level SL 1°
– Surgical candidates
– Radiculopathy
– Unilateral laminectomy
– Decomp. + instr.
and bilateral decomp.,
fusion with pedicle
n = 20
screws, local bone
graft and cage,
n = 25
– unresponsive to cons.
treatment > 3 mo
– No
– Retrospective
Median
– Decomp. only
63 mo
vs decomp. +
instr. fusion:
study
– Radicular pain
– Decomp. only vs decomp. + instr. Fusion:
Age: 67.7 vs
61.9 y
3 mo
– Yes
Female: 75% vs
8.0±0.87
ODI: 29.8±4.40 vs
24.6±5.38
SF-36 PCS: 29.2±3.67 vs
26.1±5.33
SF-36 MCS: 28.0±3.37 vs
– NRS leg, NRS
– Decomp. only vs decomp. +
back, ODI, SF-36,
instr. fusion at FU:
Yes
“Unilateral laminectomy and bilateral decomp. is
the recommendable procedure for the treatment
3b
– Methodologically poor
– Fusion
vs decomp. +
pts: ortho-
NRS back pain: 1.2±2.20 vs
instr. fusion:
sis 3 mo
2.4±1.88 (diff. between groups
especially for NRS back
P=0.001)
pain
NRS leg pain: 2.4±2.53 vs
– Key question cannot be
2.5±1.80 (diff. between groups
answered
Odom’s criteria
of pts with grade I deg. SL who have mainly
radicular pain”
– Retrospective study with
different baseline data,
Preop. slip 14.1%
vs 14.7%
NRS leg pain: 7.8±0.91 vs
– No data
– Decomp. only
NRS back pain: 2.8±3.10
vs 6.6±2.47
88%
– Min.
P=0.99)
ODI: 15.45±7.06 vs 11.0±7.09
(diff. between groups P=0.96)
SF-36 PCS: 47.2±9.42 vs
46.3±7.41 (diff. between groups
P=0.26)
29.3±3.84
SF-36 MCS: 46.7±8.54 vs
44.5±6.63 (diff. between groups
P=0.25)
Excellent 3 vs 4; Good 10 vs
10; Fair 2 vs 5; Poor 5 vs 6
(diff. between groups P=0.50)
– Surgery of 1 or 2 levels for
– Decomp. alone, n = 655
– Decomp. + fusion,
tional Swedish
lumbar SPS with degen. SL
(including only pts with
n = 651 (including
Register for Spine
(n = 1306) and without de-
degen. SL)
only pts with deg.
Surgery) / 2013 /
gen. SL
Försth et al. (Na-
– No
–
case–control study
SL)
– Age > 50 y
3 b / 1998–2008
– No
2y
– Retrospective
– Mean age 69 y
– Female73%
– All pts with degen. SL:
– No data
– Yes
– No data
– SL defined as
VAS back pain: 58±26
≥ 3 mm slip on
register study
VAS leg pain: 62±25
– No differentiation
– ODI, EQ5D,
– No sign. difference in patient
VAS back pain,
satisfaction between the 2
decomp. was not associated with an improved
VAS leg pain
groups
outcome”
3b
– Retrospective registry
study
– Methodological shortcomings (no baseline data
EQ5D: 0.36±0.31
non–instr. fusions
“In this large cohort the addition of fusion to
radiographs
on complaints differentiat-
– Decomp. alone vs decomp. +
between instr. and
[31]
Yes
ODI: 45±15
fusion at FU:
– No differentiation be-
VAS back pain: 35 (95% CI 32-
tween pts with degen. SL
37) vs 32 (95% CI 30-34)
receiving decomp. only vs
(P=0.12)
ed for both groups)
– No data on type of fusion
(instr. vs. non–instr.)
– Key question cannot be
answered; at best, trend can
decomp. + fusion
VAS leg pain: 35 (95% CI 32-
be seen that fusion pts do
37) vs 32 (95% CI 30-35)
not perform better at FU,
(P=0.17)
but without having baseline
data
EQ5D: 0.63 (95% CI 0.61-0.66)
vs 0.62 (95% CI 0.59-0.64)
– Most likely, baseline data
(P=0.34)
for both groups were not
similar
ODI: 27 (95% CI 26-29) vs 27
(95% CI 26-29) (P=0.93)
Key question 4: Is instrumented fusion with reduction more successful in relation to pain and function than instrumented fusion without reduction in adult patients with isthmic or degenerative SL?
– Dysplastic low- or high-
– Posterolateral fusion with
– Same as groups A
– “Were random-
RCT 1b / no data
grade SL with pars articularis
local autologous grafts +
and B + reduction,
ized”
[34]
defect + facet joint dysplasia
allografts, decomp., sagittal
n = 20
Benli et al./ 2006 /
– Yes
+
– Pain unresponsive to cons.
plane correction, instr. with
pedicle screws, n = 20
treatment
– Presence of neurological
– Group A: low dysplastic,
n = 10
– Group A vs B
– No details on relation of
vs C vs D:
back to leg pain
– No details on
Age: 29.2 vs
randomization
34.9 vs 32.6 vs
dysplastic, n = 10
deficits or NC
– Displacement > 25% +
– Group C: low
37.9 mo
32.4 y
– Group D: high
Female: 2 vs 2
dysplastic, n = 10
vs 2 vs 2
– No data
– Slippage
– Slippage at FU:
No
“Anterior slippage reduction did not have any
1b
additional favorable effect on clinical results”
change; P>0.05)
Group A: 6.7
– Slippage before
Group B: 29.5% (no sign.
surgery:
change; P>0.05)
Group A:
Group C: 5.5% (83.4±32.6%
30.5±5.5%
correction; P<0.01)
Group B:
Group D: 5.3% (87.1±16.1%
30.0±5.8%
correction; P<0.01)
Group C:
– JOA at FU (diff. between
32.3±8.1%
groups P>0.05):
Group D:
Group A: 17.1 (P<0.05)
study (deficiency: type of
randomization not specified, small groups)
– Conclusion: reduction
Group B: 6.8
Group C: 6.9
Groups A and C
– All pts had NC in addi-
had similar
tion to neurogenic pain
baseline data
– Methodologically well
designed and performed
Group A: 30.5% (no sign.
erding 2°
Group D: 6.7
– No previous spinal surgery
– JOA, SRS22
– JOA:
vertebral instability
– No trauma
– No data
– All pts: Mey-
– Group B: high dysplastic,
n = 10
– Yes
not necessary
Groups B and D
– No degen. changes
had similar
40.6±5.9%
baseline data
Group B: 17.2 (P<0.05)
Group C: 16.6 (P<0.05)
Group D: 16.1 (P<0.05)
– Improvements in SRS22 were
independent of surgical technique and type of SL (diff.
between groups P>0.05)
Lian et al. / 2013
– 82 pts en-
Spine J / RCT 1b /
rolled, 9 pts
2006–2009 [37]
lost, 73 pts
finally analyzed
+
– 1 level degen. SL + SPS
– PLIF + complete bilateral
– Same as group A
requiring surgery
removal of the laminae and
without reduction
– Age > 70 y
decomp. of nerve roots +
pedicle screw instr. with 2
– No previous lumbar spine
PEEK cages (filled with
surgery
bone from the posterior
elements) + reduction
simultaneous surgery
– Randomized by
– Group A, n = 36
– Min.
– Group A vs
– Severe disabling LBP +
2 y;
group B:
lower extremity pain +
NC, refractory to conserv.
serial number ac-
– Mean
Mean age 74.3 y
cording to the
33.2 mo
vs 73.8 y
quence of
Female 61% vs.
62%
L3/4: n = 2 vs
likelihood of developing
n = 32
post–decomp. instability
L5/S1: n = 3 vs
compression secondary to
– Group A vs group B:
– Yes
– No data
– VAS, ODI, JOA
– Group A vs group B:
–Standing radio-
– Radiographic
Mean operating time:
graphs
data (vertebral
126.5±23.3 min. vs 118.6±17.5
slip, focal lordosis,
min. (P=0.107)
disc height)
Yes
“In conclusion, for aged pts with degen. lumbar
designed and performed
RCT
to reduce the slipped vertebra and restore sagittal
balance. PLIF with pedicle screw fixation, with
or without reduction, provides good outcomes in
Meyerding grade
436.4±137.1 mL vs
the surgical treatment of aged pts with degen.
450.5±147.3 mL (P=0.672)
SL. Better radiological outcomes do not necessarily indicate better clinical outcomes”
– Group A vs
60.8±22.1
group B:
JOA: 13.1±3.3 vs
1° slip: n = 29 vs
12.7±3.7
n = 30
n=2
VAS at FU: 1.3±0.9 (P<0.001)
vs 1.1±0.8 (P<0.001) (diff.
between groups P=0.322)
ODI at FU: 22.4±11.7
(P<0.001) vs 23.9±11.3
2° slip: n = 7 vs
(P<0.001) (diff. between groups
n=7
P=0.578)
– Methodologically well
screws seems to be an effective surgical method
Mean blood loss:
ODI: 62.2±20.8 vs
1b
SL, a drawing-back technique with pedicle
nique and
VAS: 4.2±1.9 vs 4.0±1.7
n=3
L4/5: n = 31 vs
decomp. to relieve nerve root
≥ 3 mo
Taillard tech-
– Preoperative instability or
– Requirement of foraminal
treatment for ≥ 3 mo
consecutive se-
hospitalization
– No degen. disease in adjacent segments requiring
– Group B, n = 37
– Yes
– Reposition does not
provide better clinical
results compared to in situ
fusion in degen. SL
foraminal SPS
Average preop.
JOA at FU: 22.1±3.6 (P<0.001)
slip: 18.3±5.8%
vs 23.2±4.3 (P<0.001) (diff.
vs 19.6±7.1%
between groups P>0.05)
Slip at FU: 3.1±4.4% vs
14.3±4.4% (diff. between
groups P<0.001)
No radiographic sign of nonunion at FU
Surgical complications: 22.2%
vs 21.6%
Lian et al. / 2013
– 94 pts en-
Eur Spine J / RCT
rolled, 6 pts
1b / 2006–2008
lost, 88 pts
[36]
finally ana-
+
– 1 level isthmic SL without
– PLIF + complete bilateral
– Same as group 1
– Randomized by
– Min.
– Group 1 vs
– LBP, lower extremity
degen.
removal of the laminae and
without reduction
serial number ac-
2 y;
group 2:
pain or NC that were
cording to the
– Mean
consecutive se-
FU: 32.5
quence of
mo
decomp. of nerve roots +
disease in adjacent level
lyzed
pedicle screw instr. with 2
– No previous lumbar spine
PEEK cages (filled with
surgery
bone taken from the poste-
– Group 2, n = 43
hospitalization
≥ 3 mo
refractory to conserv.
Mean age 45.5 y
treatment for ≥ 3 mo
– Yes
– No data
– Radiographic
Mean operating time: 119 min.
graphs
data (vertebral
(range 100-160 min.) vs 125
slip, focal lordosis,
min. (range 100-180 min.)
Taillard tech-
Female 62% vs
rior elements) + reduction
63%
– Group 1, n = 45
L4/5: n = 32 vs
Meyerding grade
44.1±18.9
n = 29
group 2:
1b
– Methodologically well
degen. disease in adjacent level, single segment
designed and performed
of PLIF with pedicle screw fixation is an effec-
RCT
tive and safe surgical procedure regardless of
– Repositioning does not
whether reduction has been conducted or not.
Mean blood loss: 475 mL
Better radiological outcome does not mean better
(range 180-1030 mL) vs
clinical outcome”
provide better clinical
results compared to in situ
fusion in isthmic SL
VAS at FU: 11.7±7.6 vs
51.1±13.8
11.9±7.8 (diff. between groups
L5/S1: n = 13 vs
n = 14
“In conclusion, for the adult isthmic SL without
490 mL (range 250-840)
– Group 1 vs
ODI: 50.2±16.1 vs
Yes
disc height)
nique and
VAS: 42.5±17.5 vs
– Group 1 vs group 2:
– Standing radio-
vs. 44.9 y
– Group 1 vs group 2:
– VAS, ODI, JOA
1° slip: n = 15 vs
JOA: 15.4±3.0 vs
P>0.05)
n = 16
15.3±3.0
ODI at FU: 16.2±10.2 vs
2° slip: n = 25 vs
15.9±9.6 (diff. between groups
n = 23
P>0.05)
3° slip: n = 5 vs
JOA at FU: 24.1±2.6 vs
n=4
23.9±2.8 (diff. between groups
P>0.05)
Average preop.
slip: 28.1±11.4%
Slip at FU: 6.3±6.0% vs
vs 27.9±12.0%
17.7±9.3% (diff. between
groups P<0.001)
No radiographic sign of nonunion at FU
Surgical complications: 11% vs
9%
– Pts from 2 databases of 2
– 1-level posterolateral
– No separate control
2013 / 2c study / no
ongoing prospective studies
lumbar fusion + laminec-
group
data [35]
on the biological process of
tomy + medial facetectomy
fusion in instr. posterolateral
+ pedicle screw instr.,
lumbar 1-level fusion in pts
n = 72
Hagenmaier et al. /
– No
+
with low-grade degen. or
isthmic SL (Meyerding I° +
– No
1y
Mean age 51 y
VAS leg pain: 69.0 (range
2.0-98.0)
– No data
Meyerding grade
I: n = 36
– VAS leg pain,
VAS leg pain at FU: 5.5 (range
ODI
0.0-93.0) (P<0.001)
Female 54%
– Correlation analysis of effect of
amount of reduction
Isthmic SL 71%
Degen. SL 29%
on clinical outcome
L3/4 9%
II°)
Meyerding grade
– Radiographic
ODI at FU: 11.1% (range 0.0-
73.3%)
II: n = 36
data (vertebral
77.8%) (P<0.001)
slip, foraminal
Listhesis preop:
10.6±4.3 mm
(25.2±10.3%)
– Complete radiographic +
L5/S1 49%
diameter, disc
height, fusion
status)
Slips at FU: 8.1±5.0 mm
(P<0.001)
Foraminal diameter at FU:
ter preop.:
19.0±4.3 mm (P<0.001)
21.1±3.3 mm
Anterior disc height at FU:
7.6±3.8 mm (P>0.05)
18.7 mm)
Posterior disc height at FU:
4.3 mm (range 0-10.9 mm)
(P>0.05)
Posterior disc
height preop.:
4.8±2.5 mm
radiographic reduction of the slipped vertebra.
no evidence that it positively affects clinical
outcome”
2c
– Methodologically limited
design
– Not a controlled trial
– Simple 1-cohort study
with
data from 2 databases
– Only little data on pts
included
– No correlation between
slip reduction and clinical
outcome
height preop.:
7.7 mm (range 9-
“Clinical outcome was not related to the obtained
(17.4%; range 0-59.7%)
Foraminal diame-
Anterior disc
Yes
Although reduction remains appealing, there is
ODI: 44.4% (range 8.9-
L4/5 42%
clinical FU
– No data
Fusion rate on CT at FU: 64%
“No correlation could be established between slip reduction
and clinical outcome” (Pearson’s correlation VAS -0.204;
ODI 0.066)
Fusion vs nonfusion: no sign.
clinical diff.
Isthmic vs degen. SL: higher
preop. VAS for degen. SL
(P<0.01), at FU no sign. clinical
diff. in improvements in VAS
and ODI
Abbreviations: +/–, with or without; CD, Cotrel–Dubousset; CI, confidence interval; conserv., conservative; CT, computed tomography; decomp., decompression; degen., degenerative; diff., difference; DRI, Disability Rating Index; DS, degenerative spondylolisthesis; EQ5D, EuroQoL
5D; FU, follow-up; instr., instrumentation/instrumented; JOA, Japanese Orthopedic Association (score); LBP, low back pain; LBPBI, Low Back Pain Bothersomeness Index; LoE, level of evidence; LPBI, Leg Pain Bothersomeness Index; MCS, mental component summary (score);
min., minute(s) or minimum; mo, month(s); NC, neurogenic claudication; NRS, Numeric Rating Scale; NSAID, nonsteroidal anti-inflammatory drug; ODI, Oswestry Disability Index; PCS, physical component summary (score); PEEK, polyetheretherketone; PLF, posterolateral lumbar
fusion; PLIF, posterior lumbar interbody fusion; pts, patients; RCT, randomized controlled trial; SBI, Stenosis Bothersomeness Index; SF-36, Short Form-36 (questionnaire); sign., significant; SL, spondylolisthesis; SPORT, Spine Patient Outcome Research Trial; SPS, spinal stenosis;
TE, treatment effect; VAS, visual analogue score; vs, versus; wk, week; y, year(s); ZCQ, Zurich Claudication Questionnaire.