Appendix 3
A. High quality studies (n=7)
B. Randomized controlled trials (n=1, HQ one)
C. Low quality studies (n=13)
A.
'High quality' -studies including predictors for postoperative outcome of operated LSS
Abbreviations: Superscript “a”= quality percent. N=number of patients. F=latest follow-up. LSS=lumbar spinal stenosis. HNP=herniated nucleus pulposus. q=amount of questions (in used questionnaire). mo=month(s).
Details of each study are presented as above
____________________________________________________________________________________________________________________________________________
Author (year)a
i) = study design
ii) = intervention
iii) = outcome measures
Reported prognostic factor(s)
Influence on outcome
Study title, N, F
Objectives
____________________________________________________________________________________________________________________________________________
Frazier (1997)62%
i) Observational study
ii) Laminectomy, medial facetectomy when necessary. 23% had concomitant arthrodesis with or without instrumentation
iii) Questionnaires by Stucki et al. 1996 including back/leg/overall pain, and difficulty ambulating using Likert-scale from 1 (best) to 5 (worst); walking capacity (5q); satisfaction (6q)
Greater preoperative scoliosis
Associated with back pain (p<0.05, r= -0.29 (6 mo),
Associations between spinal deformity
To examine associations
r= -0.25 (24 mo)), not with satisfaction, leg pain
and outcomes after decompression for
between radiographic
or walking capacity
spinal stenosis
parameters (scoliosis and
The extent of preoperative
spondylolisthesis
Iversen (1998)62%
N=90
olisthesis) and outcomes of
F=2 years
surgery for degenerative LSS
NS
i) Observational, multicenter study
ii) Decompressive surgery for LSS (23% one-level, 33% two-level, 44% ≥3 levels; arthrodesis for 29%)
iii) Functional status (Sickness Impact Profile), walking capacity (4 q), pain (6-point scale), postoperative resource use; satisfaction with pain relief (4q) and physical function (2q)
Preoperative expectations (e)
The prognostic importance of patient
To a) relate patient expectations
-greater number of e:s
Associated with improved global function
(p=0.003)
preoperative expectations of surgery for
of surgery to baseline
-more e:s with pain relief
Associated with more pain
(p=0.009)
lumbar spinal stenosis.
function and pain
N=257
b) determine how patients
F= 6 months
expectations and preopera-
Higher baseline pain
Associated with more pain
(p=0.003)
Baseline depression
-"-
(p=0.003)
Better baseline global function
Better global function
Fewer comorbidities
Better walking capacity
-"-
(beta=0.5, p=0.0001)
predict postoperative
(beta=0.06; p=0.005)
outcome
Better walking capacity
(p=0.0001)
Younger age
-"-
(p=0.0006)
Male gender
-"-
(p=0.003)
Higher baseline walking capacity
tive function interact to
Better satisfaction with walking capacity
(p=0.0001)
Female gender
-"-
(p=0.025)
More ambitious expectation of physical function
-"-
(p=0.043)
Javid (1998)62%
i) Observational study
ii) Decompressive laminectomy; bilateral laminectomy and medial facetectomy for LSS (n=86; fusion for nine patients) and LSS with HNP(n=61). 23 patients had lateral stenosis
iii) Pain, satisfaction, clinical examination, employment.
Diagnoses as predictive factors:
LSS vs. LSS+HNP
NS (6week; 6mo; 1 yr; and 1-11year follow-ups)
Long-term follow-up review of patients
To evaluate long-term
Lateral stenosis vs. (LSS+HNP, LSS)
NS (lat. stenosis: a trend with inferior result)
who underwent laminectomy for lumbar
results (of surgery) in
Obesity and sex
NS (at 1-year follow-up)
stenosis: a prospective study
patients with symptomatic
N=170
spinal stenosis
F=11 years
Jönsson (1993a)62%
i) Observational, consecutive study
ii) Decompression without fusion in secondary operation
iii) Neurological examination, pain back/leg (4-scale), effect of work, consumption of analgesics, walking capacity
In previous operation, 28 lumbar spinal stenosis patients had had decompression (two had also arthrodesis);
Repeat decompression of lumbar nerve
To find prognostic factors
65 discectomy; diagnosis at the repeat operation were: central LSS (cent) in 20, lateral LSS (lat) in 19,
roots; a prospective two year evaluation
which could be applied for
disc herniation (DH) in 19 and periradicular fibrosis (PRF) in 35 patients
F=2 years
second surgical procedure
Limitation : Diagnoses are based partially on operative findings, being thus peroperative predictors
of spine; to report
Diagnosis of reoperation
Significant better results in patients, who had prolapse
epidemiology of recurrent
or LSS versus PRF (p=0.0001)
or residual pain in study
Single root affection (due to DH/lat)
population
vs. central LSS
Better results in single root affection (P=0.0006)
Age, gender, type of work
NS
Jönsson (1994b)85%
i) Observational, consecutive study
ii) Lumbar nerve root decompression
iii) Pain (back/leg separately; 4-grade scale), walking capacity, neurological examination, employment
Long preoperative duration of
Worse long-term results (p=0.036)
Decompression for lateral lumbar
Surgical results and impact on
low back pain and sciatica in lateral stenosis
stenosis - Results and impact on
sick leave and working conditions
(subjective evaluation excellent/good/fair/poor )
sick leave and working conditions
in patients who underwent surgery
N=100
for lateral spinal stenosis were
F=2 years
evaluated in prospective,
Type of work
No influence on surgical outcome
(sedentary/moderate/heavy)
More sedentary workers returned
consecutive study
to their previous work (p=0.013)
Jönsson (1997)77%
i) Observational consecutive study
ii) Laminectomy (20% one level, 45% two-level, more 35%; no fusion) with a facet-preserving technique; operation procedure extended laterally to identify each nerve root
iii) Patient´s opinion of the outcome, with opinions regarding back and leg pain separately (4 grade scale); walking ability estimation (improved/not improved); pain at rest/night
Pronounced stenosis of the spinal
Significant correlation with a favourable outcome
canal (ant-post diameter 6mm)
Comorbid disorder affecting
Significantly worse outcome
walking ability
Duration of sciatica-claudication
symptoms <4 years
Tendency toward better outcome
(not significant)
Insignificant lower back pain
Age, gender
-"NS
A prospective and consecutive
To evaluate the result after
study of surgically treated lumbar
surgical decompression for LSS,
spinal stenosis - Five year follow
at regular intervals after surgery,
up by an independent observer
and to correlate these results with
N=105
values for preoperative parameters;
F=5 years
special interest was focused on the
results in relation to the degree of
constriction of the spinal canal
Katz (1999)69%
i) Observational study
ii) Laminectomy with or without arthrodesis for degenerative LSS
iii) Walking capacity, symptom severity, satisfaction measured by multi-item questionnaire (Stucki et al. 1996)
Multivariate model (B=standardized beta coefficient)
Better self-rated health
Less cardiovascular comorbidity
Better walking capacity
_
Better walking capacity
(B 3.8; p=0.002)
Predictors of surgical outcomes in
To identify outcome predictors of
Less severe symptoms
(B 3.6; p=0.0005)
degenerative lumbar spinal stenosis
surgery for degenerative LSS
Better satisfaction
(B 3.3; p=0.001)
N=199
Better walking capacity
(B 2.7; p=0.008)
F=2 years
Less severe symptoms
(B 2.6; p=0.01)
Better satisfaction
(B 3.7; p=0.0002)
Better walking capacity
(B 2.5; p=0.01)
No values for symptom severity and satisfaction
Better mental health (3-item scale)
Less severe symptoms
(B 2.3; p=0.02)
Better satisfaction
(B 1.9; p=0.05)
No values for walking capacity
Higher income
Better walking capacity
(B 2.2 (0.03)
Less severe symptoms
(B 2.4; p=0.02)
Better satisfaction
(B 1.9; p=0.05)
Univariate preoperative predictors of walking capacity, symptom severity and satisfaction 24months after surgery___________________________
(NS=not significant; SP=Spearman correlation; Wc=walking capacity; Sy=symptom severity; Sat=satisfaction)
Continuous predictors and outcomes
Age
NS (SP=0.06-0.14 in Wc, Sy and Sat)
Walking capacity
Wc:SP=0.30, p<0.0005; Sy: SP=0.20, p<0.005; Sat NS, SP=0.08
Symptom severity
Wc:SP=0.24, p<0.0005; Sy: SP=0.25, p<0.005; Sat NS, SP=0.08
Overall comorbidity
Wc: SP= 0.33, p<0.0005; Sy:SP=0.27, p<0.0005; Sat: SP=0.23, p<0.005
Cardiovascular comorbidity
Wc: SP=0.30, p<0.0005; Sy:SP=0.0.24, p<0.005; Sat: SP=0.25, p<0.0005
Musculoskeletal comorbidity
NS (SP=0.13-0.17)
Social support scale
NS (SP=0.01-0.03)
3-item depression scale
Wc:SP=0.19, p<0.005;Sy:SP=0.29, p<0.0005;Sat:SP=0.25, p<0.0005
Mean outcomes associated with categorical predictors (Outcomes: 0=the best, 100=the worst)_______________________________________________
Baseline predictor
Male/female
NS
No college/some college education
NS
Income< $15,000
$15,000-50,000
NS
$>50,000
NS
Leg pain>back pain
NS
Back painleg pain
NS
Pinprick sensation normal or abnormal
NS
Lower extremity weakness
NS
Normal strength
NS
Radiological findings
-scoliosis<15
NS
-scoliosis15
NS
-spondylolisthesis5mm
NS
-spondylolisthesis<5mm
NS
Wc
Sy
Sat
(p<0.0005)
(p<0.005)
NS
Self-rated health: -Excellent
-Good, fair, poor
(p<0.0005)
NS
(p<0.0005)
(p<0.0005)
B.
Randomized controlled trial (HQ) including predictors for postoperative outcome of operated LSS (n=1)
Abbreviations: Superscript “a”= quality percent. N=number of patients. F=latest follow-up. LSS=lumbar spinal stenosis. HNP=herniated nucleus pulposus. q=amount of questions (in used questionnaire). mo=month(s).
_____________________________________________________________________________________________________________________________ _______________
Author (year)a
i) = study design
ii) = intervention
iii) = outcome measures
Reported prognostic factor(s)
Influence on outcome
Study title, N, F
Objectives
____________________________________________________________________________________________________________________________________________
Amundsen (2000)69%
i) 19 patients with severe symptoms were selected for surgical treatment, and 50 patients with moderate symptoms for conservative treatment; 31 patients were randomized between
conservative (n=18) and surgical (n=13) treatment groups
ii) Surgical treatment: standardized for the purpose of nerve decompression by partial/total laminectomy, medial facetectomy, discectomy, and/or removal of osteophytes from the
vertebral margins or facet joints. One-level 8%, two-level 52%, three-level 29%, four-level 11%. No fusions. Postoperatively, a hyperextension thoracolumbar orthosis was used and
after 1 week, the patients were transferred to the rehabilitation department for a period of 1 month. Sitting was not allowed during this period. No specific physiotherapy was given
except instructions and “back school”.
Conservative treatment: The same type of orthosis as above was fitted, and transfer to the rehabilitation department for 1 month was done. The orthosis was worn during the day for all
activities, and patients were encouraged move around normally. No specific physiotherapy was given except instructions and “back school”. The patients were observed daily by the
physiotherapists and three times a week by a physician.
After 1 month (both groups), the patients were discharged from the hospital. Further treatment was identical for both groups consisting of wearing the orthosis for 2 more months. After
that, physiotherapy started which consisted of general physical training. No attempt was made to improve mobility of the spine, and the patients were instructed to try holding the back
in a slightly kyphotic position
iii) Pain (verbally, visual analogue scale); claudication distance, effect of bending forward/backward; employment status; neurological examination; subjective evaluation
(better/worse/unchanged); the changes were recorded. The overall result was summarized according to the aforementioned data (excellent/fair/unchanged/worse)
Clinical predictors
Predictors for the final outcome were not found
Lumbar spinal stenosis: Conservative
or surgical treatment?
To identify the short and long-term
-
physical findings
-
Lasegue's sign
N(surgical)=32
conservative treatment and
-
level of spinal protein
N(conservative)=68
followed for 10 years
F=10 years
Radiologic predictors (see text for details)
NS
-
multilevel afflictions
NS
-
advanced degenerative changes
NS
Advanced age
NS
Gender
NS
Married/not married
NS
Type of work
NS
Physical loading
NS
Satisfaction at home and work
NS
Duration of pain
NS
Length of sick listing
NS
Level of physical activity
NS
Smoking habits
NS
results after surgical and
C.
'Low quality' prospective studies including predictors for postoperative outcome of operated LSS (n=13).
Abbreviations: Superscript “a”= quality percent. N=number of patients. F=latest follow-up. LSS=lumbar spinal stenosis. HNP=herniated nucleus pulposus. q=amount of questions (in used questionnaire). mo=month(s).
____________________________________________________________________________________________________________________________________________
Author (year)a
i) = study design
ii) = intervention
iii) = outcome measures
Reported prognostic factor(s)
Influence on outcome
Study title, N, F
Objectives
_____________________________________________________________________________________________________________________________ _______________
Gunzburg (2002)38%
i) Observational consecutive study
ii) Partial laminectomy/arthrectomy
iii) Functional status: Waddell Disability Index, (Low Back Outcome Score); VAS; reduction of pain during walking, reduction of leg pain. Also, the satisfaction of hospital stay,
operation, and the wish to have the same operation again was asked
Illness behaviour
Gender
was concluded to play an important role in surgical outcome
Clinical and psychofunctional
Conclusion was based on higher-than-expected-rate of non-
measures of conservative
The aim of the study was to
organic signs -score pre- and postoperatively
decompression surgery for lumbar
evaluate short-term psychometric
spinal stenosis: A prospective cohort study.
and functional outcomes after
conservative decompression
No statistically differences between subgroups
Operative age
(with respect to satisfaction/wish to have same
N=40
Stenosis classification
operation again)
F= 1.7yrs (mean; range 1-2.6)
Herkowitz (1991)46%
i) Comparative, consecutive study
ii) Decompressive laminectomy (n=25), or decompressive laminectomy+bilateral lateral intertransverse-process arthrodesis with bone graft; postoperative management was same for both
groups; progressive walking (ten to twenty minutes, twice daily) during the first 4-6 weeks; exercises on a stationary bicycle or in water were begun at 6-8 weeks, and exercises for
gentle flexion of the spine and strengthening of the abdominal muscles were added at eight to twelve weeks; no brace or corset was used
iii) Back/leg pain measured separately with scale 0-5 (0=no pain; 5=severe pain); operative result measured with 4-grade scale (excellent = unrestricted activity and/or complete pain relief
in back/legs; good=occasional discomfort (back/leg) necessitating non-narcotic medication, major improvement with preoperative condition, and resumption of unrestricted activity;
fair=intermittent discomfort; improvement compared with preoperative condition; restrictions of activity, and occasional need for non-narcotic medication; poor=major discomfort, nonnarcotic or occasional narcotic medication; no improvement, major restrictions of activity
Age
NS
Degenerative lumbar spondylolisthesis with
To determine if concomitant intertransverse-
Gender
NS
spinal stenosis - A prospective study comparing
process arthrodesis provided better results
Height of disc
NS
decompression with decompression and inter-
than decompressive laminectomy alone
transverse intertransverse process artrodesis
N= 50
F= 3 years (range 2.4-4)
Jönsson (1993b)31%
i) Observational, consecutive study
ii) Decompressive operation for central (N=80), lateral (n=80) LSS and HNP (n=120)
iii) 4-grade scale (pain free, almost pain free, improved but significant residual pain, unchanged compared to preoperatively, and worse than preoperatively)
Regular consumption of analgesics in
Associated with unfavourable outcome (pain)
central stenosis
Patient related factors predicting the outcome
of decompressive surgery
Long preop. duration of sciatica in lat. stenosis
Associated with poor outcome (pain)
N=280
Long preop. duration of back pain
NS
F=2 years
Age
NS
Gender
NS
See study title
Jönsson (1993c)31%
Time off work
NS
Work load
NS
Walking distance (reported)
NS
i) Observational consecutive study
ii) Resection of processus spinosus, the laminae and maximally half of the facet joints using the undercutting technique (one-level 22%, two-level 55%, three-level 18%, four-level 5%)
iii) Sagittal vertebral slipping (listhesis) in millimetres according to Wiltse and Winter, and slip exceeding >2mm was regarded as true
Limitation: Preoperative predictor is operation-dependent
No preoper. degenerative olisthesis (2mm),
Postoperative vertebral slipping was avoidable
and facet sparing technique utilized
Jönsson (1994a)46%
Vertebral slipping after decompression for
Not defined. The increase
spinal stenosis
of postoperative vertebral
Preoper. degenerative olisthesis 2mm
30% risk of progressive slip, but without associated
N=60
slipping and its relation
and facet sparing technique utilized
clinical problems in the short term
F= 1 year
to outcome reported
i) Observational, consecutive study
ii) Decompression with facet-preserving technique in spinal stenosis (central LSS n=40; lateral LSS n=3) and conventional open disc excision for HNP (n=4)
iii) Amount of complications; 4-grade subjective pain scale (excellent=almost/totally pain free; fair= improved but residual pain; unchanged; worse (compared to preoperative condition))
All patients were over 70 years, no control group
Lumbar spine surgery in elderly-
Diagnosis, postoperative compli-
Age >70 years
Results were on par with those of decompressive
complications and surgical results
cations, and surgical result in
surgery in younger patients(compared to literature)
N=50
patients over 70 years old who
More favorable results concerning sciatica (results
F=2 years
underwent surgery for lumbar
included all the patients)
Limitation: study population had
nerve root compression of a
no control group (younger patients),
degenerative origin were evaluated
thus the conclusion concerning age
in a prospective, consecutive study
No back pain preoperatively
age was not based on the actual
population
Jönsson (1995)38%
i) Observational consecutive study
ii) For LSS: decompression with facet-preserving technique; for HNP: open conventional or microscopic disc excision; no fusions were performed
iii) Extensor hallucis longus power (3-grade scale): normal, reduced, severely reduced
Katz (1995)38%
Prognostic factors of the recovery of L5-root syndrome (extensor hallucis longus(EHL) -power severely reduced):
Motor affliction of the L5 nerve root in
The incidence, diagnosis
Diagnosis (p=0.02, Kruskal-Wallis)
lumbar nerve root compression syndromes
and recovery after
-
central spinal stenosis
The prognosis of EHL-power recovery was poor (0%)
F= 4 month; 1- and 2 years
surgery of patients with
-
lateral spinal stenosis
80% improved, no total recovery
-5 spinal stenosis patients
L5 root compression
-
disc herniation
56% total recovery, 28% improved
-10 lateral stenosis patients
syndromes and a severely reduced
Age
NS
-20 disc herniation patients
or absent power before surgery of
Duration of preoperative symptoms
NS
the big toe extensor was evaluated
i) Multicenter observational cohort study
ii) Decompressive laminectomy for LSS (one-level 25%, two-level 36%, three-level 26%, four-level 13%; no fusion 70%; bony fusion 15%, bony fusion with instrumentation 15%)
iii) Global 4-grade satisfaction score (1=very satisfied to 4=very dissatisfied)
Multivariate analysis of patient satisfaction with the results of surgery
Clinical correlates of patient
To identify correlates of patient
(Sat=satisfaction; B=beta coefficient; SIPS=sickness impact profile score)
satisfaction after laminectomy
satisfaction with the results of
Back pain
for degenerative lumbar spinal
surgery
Significant association for lesser Sat (B=0.17, p=0.005)
Functional disability (SIPS)
-"-
(B=0.02, p=0.006)
stenosis
Greater medical comorbidity
-"-
(B=0.08, p=0.03)
N=194
Age
No association with satisfaction
Gender
-"-
Depression score
-"-
F= 6 months
Overall severity of pain in back, buttocks or legs
Kleeman (2000)38%
-"-
i) Observational consecutive study
ii) Decompression technique included complete excision of the ligamentum flavum through a modified laminotomy
iii) 3-grade scale (good-excellent: absent or occasional mild back and leg pain; to be able to ambulate >1 mile or 20 minutes, no restriction of usual activities; fair= persistent mild back/leg
pain, ambulation endurance < 1 mile or 20 minutes; some mild restrictions in their customary physical activity; poor= little to no pain relief from surgery, major activity limitations, or
both. A repeat operation for any reason was considered a poor result, regardless of the ultimate level of the function
Degenerative spondylolisthesis in
NS; slight tendency to less favorable outcome
Patient outcomes after minimally destabilizing
To determine whether decompression
lumbar spinal stenosis
(p=0.11 at 2.5- and 0.08 at 4-year follow-up
lumbar stenosis decompression -
could be achieved without subsequent
The "Port-Hole" -technique
fusion for spinal stenosis with and
N=54 ; F(mean)= 30 and 48 months
McGregor (2002a)31%
without degenerative spondylolisthesis
i) Observational study
ii) Posterior decompression for LSS (83% bi-,17% unilateral; fusion in 6%; 77% had ≥2 levels and 23% one level decompressed; 7 patients chose conservative treatment)
iii) Visual analogue scale (worst and usual pain over the past week); Oswestry Disability Index, SF-36 General Health Questionnaire; psychological measures as mood, depression, anxiety and helplessness
Subjective disability (Oswestry disability index)
Outcome could not be reliably predicted
The evaluation of the surgical management
To investigate the
Physical function (SF-36 general health questionnaire)
from presurgical measures of function,
of nerve root compression in patients with
outcome of lumbar
Pain (leg and back pain studied separately)
disability, pain and psychological well-
low back pain - Part 1:The assessment of outcome decompressive surgery
Psychologic variables
being
N=84 patients undergoing LSS surgery
in the initial post-
Age
No influence on outcome
F = 6weeks, 6mo and one year
operative year period
Gender
-"-
in terms of function
Preoperative duration of symptoms
-"-
disability, general
Smoking
-"-
health and
Earlier surgery
McGregor (2002b)15%
Was associated with many outcome measures, but
psychological
no consistent pattern was observed
well-being
i) Observational study (same population as in McGregor 2002a)
ii) Posterior decompression for LSS (83% bi-,17% unilateral; fusion in 6%; 77% had ≥2 levels and 23% one level decompressed; 7 patients chose conservative treatment),
iii) the patient were asked to rate the percentage of improvement they expected after surgery at 6 weeks, 6 months, and 1 year on a 5-point Likert scale (range 0=no improvement,
100%=full improvement) with respect to function, general health, pain and life satisfaction; in addition, they ranked how satisfied they expected
to be, how confident they were in achieving a satisfactory outcome, and how important such an outcome was to them (5-point Likert scale based on percentage improvement);
Oswestry Disability Index (function), SF-36 General Health Questionnaire (leg and back pain separately with visual analogue scale, general health) and Cantril Life Satisfaction scale
were measured at every review stage and the actual and expected score was compared
Preoperative expectations of outcome measured by
Patients frequently had unrealistic expectations
The evaluation of surgical management of nerve
To investigate patient
-General health (SF-36 General Health Quest.)
and as a consequence tended to have lower
root compression in patients with low back pain
expectations of
- Subjective function (Oswestry)
levels of satisfaction
N=84
surgery and short- and
F=1 year
long-term satisfaction
- Life satisfaction (Cantril Life Sat. Scale)
with the outcome of decompression
in terms of pain, function, disability and general health
Sato (1997)38%
i) Observational consecutive study; 81 LSS patients with or without degenerative spondylolisthesis were divided into two groups; one level stenosis (n=53) and two-level stenosis (n=28);
ii) In 2-level stenosis, the responsible level was determined with gait load test and selective nerve root block; all patients underwent selective decompression at the neurologically
responsible level only
iii) Assessment of Treatment for Low Back Pain made by the Japanese Orthopaedic Association
Gait load test and selective nerve
Used together, were helpful in determining responsible
Clinical analysis of two-level compression
To clarify the clinical features
root block
level in two-level stenosis (and improving results; no
the cauda equina and the nerve roots in
of two-level stenosis regarding the
control group)
lumbar spinal canal stenosis
neurologic level responsible for the
N=81
symptoms, neurogenic intermittent
F=4.6 years (range 1-8)
claudication and the outcome of
selective decompression
Spratt (2004)46%
i) Consecutive cohort study - was designed to develop predictive models for surgical outcome based on information available prior to lumbar stenosis surgery
ii) Partial laminectomy/arthrectomy
iii) Functional status: Waddell Disability Index, (Low Back Outcome Score); VAS; reduction of pain during walking, reduction of leg pain.
-Chi-squared automatic
Predicted 90.1% of successful outcomes;
A predictive model for outcome after
interaction detection
preliminary model
conservative decompression surgery
-More Waddell´s
OR=0.648, 90% CI=0.362-0.991, p=0.08)
for lumbar spinal stenosis
non-organic signs
NS trend toward inferior outcome
Age
NS
Gender
-"-
Stenosis class
-"-
-acquired
-mixed
Minimal or mean canal diameter
-"-
at oper. site ( mm)
Yukawa (2002)46%
Flexion:extension velocity ratio
-"-
Continuous pain
-"-
Aorta calcification
-"-
Smoker
-"-
Comorbidities
-"-
Duration of symptoms
-"-
i) Observational study
See above i)
ii) Decompressive surgery for LSS; all patient had neurogenic claudication (74% underwent also posterolateral arthrodesis with instrumentation because of instability)
iii) Visual analogue scale, Oswestry Disability Index, and neuroradiological imaging
Cross-section of dural-tube <70mm2
Patients with dural tube <70mm2 had
A comprehensive study of
To evaluate patients undergoing
vs. >70mm2
better postoperative reported functional ability (Oswestry)
patients with surgically treated
surgery for LSS and intermittent
Multilevel central stenosis
Shorter walking distance (with treadmill) pre- and
lumbar spinal stenosis with
neurogenic claudication with
postoperatively (p<0.05)
neurogenic claudication
functional testing, quantitative
No association with pain (VAS)
N=62
imaging, and patient self-
No association with functional ability (Oswestry)
F= minimum 2 years
assessment