Session 6: Spine
Torsdag den 22. oktober
09:00 – 10:30
Lokale: Helsinki/Oslo
Chairmen: Ebbe Stender Hansen / Stig Mindedahl Jespersen
61. Cobb angel measurement without X-ray, a novel method.
Ane Simony, Karen Hoejmark Hansen, Hanne Thomsen, Mikkel Meyer Andersen, Morten Vuust
Sector for Spine Surgery & Research, Middelfart Hospital; Department of radiology, Frederikshavn Sygehus; Department of Mathematics and Statistics., Aalborg University
Background: Cobb angel measurement is the most
important tool, to determine curve
progression and effect of treatment. The
patients are children or adolescent and
standard x-rays of the spine expose the
breast area, the thyroid, and the gonads,
with ionizing radiation. Increased
incidence of cancer is observed among
patients, treated for adolescent
idiopathic scoliosis.
Purpose / Aim of Study: To validate the accuracy of The Manual
Method, against convention radiographs.
Materials and Methods: 130 consecutive patients, referred to
standing x-ray of the spine, were invited
to participate. 78 patients fulfilled the
inclusion criteria. Before x-ray, the
Spinous processes where manually
palpated from T1 to S1, and marked with
a pen. The patient was placed for X-ray,
and the photo was taken with the patient
standing in exactly the same position, as
the AP X-ray. Marking and photographs
where taken by a Research nurse. X-
rays were evaluated by 2 independent
doctors, and the photographs were
evaluated by the same 2 doctors, 2
weeks later. The measurements where
evaluated by an independent statistician.
Findings / Results: For the thoracic curves, the mean
difference was 6.9 (p value < 0.0001),
such that on average, the angle
measured with x-ray was 6.9 degrees
larger than that measured with photo.
The Pearson correlation between x-ray
and photo angle was 0.58 (p value <
0.0001).
For the thoracolumbal curves, the mean
difference was 5.2 (p value < 0.0001).
The Pearson correlation between x-ray
and photo angle was 0.66 (p value <
0.0001).
In the lumbar group, only 7 patients
participated. This is not enough to
evaluate the methods feasibility, and
these results are not presented.
Conclusions: The method has been proven
successful in thoracic and the thoraco-
lumbar region. Further examination is
needed, to evaluate if this method is
useable in the lumbar region.
62. Incidence of cancer and infertility, in patients treated for adolescent idiopathic scoliosis 25 years prior.
Ane Simony, Leah Y Carreon, Karl Erik Jensen, Steen Bach Christensen, Mikkel Ø Andersen
Rygkirurgisk afdeling, Middelfart Sygehus; Neuroradiologisk afdeling, Rigshospitalet
Background: Adolescent females with idiopathic
scoliosis are exposed to substantial
amounts of radiation during treatment
and follow-up for AIS.
Purpose / Aim of Study: The purpose of this study was to
determine the amount radiation exposure
patients received during treatment for
AIS and report the incidence of infertility
and cancer in adulthood.
Materials and Methods: 219 consecutive AIS patients treated at
Rigshospitalet, Copenhagen between
1983-1990 were invited to participate in
a follow-up study. The incidence of
cancer was determined through chart
review and interviews. In addition, the
subjects and age-matched controls
were queried regarding infertility, age at
first pregnancy and spontaneous
abortions.
Using X -ray reports that included patient
position, mAs and kV used and the
number of x-rays taken, a radiation
physicist calculated the total radiation
dose during treatment and follow-up
adjusted for BMI and sex.
Findings / Results: 159 (78 %) patients participated in the
follow up study, and medical charts
were available in 209 patients. 2 patients
had passed away, one due to cardiac
arrest and one to breast cancer. 8
patients had emigrated. Radiation
information was available in 211
patients. The mean calculated total
radiation exposure was 1.58 mSv (0,44-
6,9). 16.3 (range, 8-34) x-rays were
taken during treatment.
The rate of infertility (10%) and
spontaneous abortion (23%) is similar to
the normal controls. 9 (4.3%) AIS
patients developed cancer, mostly
breast (3) and endometrial (4). The
incidence of cancer in this cohort is 17
times greater than the incidence of
cancer in the Danish agematched
population.
Conclusions: The infertility and spontaneous abortion
rate was similar between AIS patients
and an age matched cohort. The cancer
rate in the AIS patients is 17 times higher
than expected compared to the age-
matched Danish population.
63. Health-related Quality-of-life in Adolescent idiopathic scoliosis patients 25 years after treatment
Ane Simony, Leah Y Carreon, Steen Bach Christensen, Mikkel Ø Andersen
Rygkirurgisk afdeling, Middelfart Sygehus
Background: Very few longterm studíes exists,
focusing on the health realted outcomes
after scoliosis treatment.
Purpose / Aim of Study: The purpose of this study was to
evaluate the long term clinical outcomes
using validated measures of health-
related quality-of-life (HRQOL), 25 years
after termination of treatment for
adolescent idiopathic scoliosis.
Materials and Methods: 219 consecutive patients treated with
Boston brace or posterior spinal fusion
(PSF) using Harrington- DDT
instrumentation between 1983 and 1990
at Rigshospitalet Copenhagen, were
invited to participate in a long-term
evaluation study. A validated Danish
version of the Scoliosis Research
Society 22R (SRS22R) and Short Form-
36 (SF36v1) were administrated to the
patients two weeks before the clinical
and radiological examination.
Findings / Results: 159 (72,6 %) patients participated in the
clinical follow up and questionnaires, 11
patients participated only in the
questionnaires, 8 emigrated, 4 were
excluded due to progressive
neurological disease and 2 were
deceased. The total follow up was 170
patients (83%), and the average follow
up was 24.5 years (range, 22-30 years).
SRS22R domain scores were within the
range described as normal for the
general population with no statistical
difference between the groups except
in the Satisfaction domain, where the
PSF group had better scores than the
braced group.The SF36 PCS and MCS
scores in both AIS cohorts were similar
to the scores for the general population.
Conclusions: HRQOLs, as measured by the SRS22R
and SF-36, of adult AIS patients treated
with Boston brace or PSF during
adolescence were similar to the general
population. No clinical progression of the
deformity has been detected during the
25-year follow up period. The PSF group
had a small but statistically significant
higher score in the Satisfaction domain
compared to the braced group.
64. The association between severity of scoliosis and lung clearance index (LCI) in patients with adolescent idiopathic scoliosis (AIS)
Anne Katrine Blyme, Birgitte Hanel, Martin Gehrchen, Benny Dahl
Spine Unit, Department of Orthopaedic Surgery, Rigshospitalet and University of Copenhagen; Danish Pediatric Pulmonary Service, Rigshospitalet and University of Copenhagen
Background: AIS causes thoracic distortion but the effect on ventilation inhomogeneity is
scarcely reported. The lung clearance index (LCI) is an advanced pulmonary
function test reflecting ventilation inhomogeneity of the lungs.
Purpose / Aim of Study: To assess the correlation between LCI and Cobb angle in AIS-patients.
Materials and Methods: A consecutive series of patients with AIS was included. Pulmonary function testing
using spirometry, wholebody-plethysmography and N2 MBW was performed obtaining:
forced expiratory volume in 1 s (FEV1) and capacity (FVC), total lung capacity (TLC),
and LCI.
An independent observer registered largest Cobb angle and apical vertebrae.
Correlation analysis using Spearman´s correlation test was applied due to the index
nature of the LCI. Comparison of LCI-values with reference values was done using
unpaired t-test. A p-value < 0.05 was considered significant.
Findings / Results: The study population consisted of 41 patients with an average age of 14.7 (10-18) years. The average
Cobb angle was 49 (11-99) degrees and 88% of the curves were thoracic. LCI was significantly
increased in AIS-patients compared to the age matched reference population; 7.35 vs. 6.54 (p =
0.001).
There was a significant correlation between Cobb angle and LCI (r = 0.477, p = 0.002), whereas the
correlation between TLC and largest Cobb angle was small and not statistical significant (r = 0.273, p =
0.084). No significant correlation was found between Cobb angles and spirometric values.
Conclusions: Increased LCI indicates increased pulmonary ventilation inhomogeneity in AIS, reflecting a more
complex affection of lung function than previously reported. Future studies will reveal if surgical
treatment improves LCI or can be used as an additional variable in the assessment of curve
progression.
65. The Effect of Lumbar Disc Degeneration and Low Back Pain on the Lumbar Lordosis in Supine and Standing: A Cross-Sectional MRI Study
Bjarke Brandt Hansen, Tom Bendix, Jacob Grindsted, Robert GC Riis, Philip Hansen, Mikael Boesen
The Parker Institute, Department of Rheumatology, Copenhagen University Hospital, Bispebjerg and Frederiksberg, Denmark.; Spine Center Copenhagen, Copenhagen University Hospital, Glostrup, Denmark.; Department of Radiology, Copenhagen University Hospital, Bispebjerg and Frederiksberg, Denmark.; Department of Radiology., Copenhagen University Hospital, Bispebjerg and Frederiksberg, Denmark.
Background: The lumbar lordosis increases with a
change of position from supine to standing
and is known as an essential contributor to
positional morphological changes. It is
unclear how the lordosis is affected by disc
degeneration and low back pain (LBP) in
standing positional magnetic resonance
imaging (pMRI).
Purpose / Aim of Study: To examine the influence of LBP and lumbar
disc degeneration (LDD) on the lumbar
lordosis.
Materials and Methods: Patients with LBP above 40 on a 0-100 mm
visual analogue scale (VAS) both during
activity and rest; and a sex and age-decade
matching control group without LBP were
scanned in the supine and standing position
in a 0.25 T open MRI unit (G-Scan). All
images were evaluated and LDD was
graded using Pfirrmann’s classification.
Subsequently, the L2-S1 lumbar lordosis
angle was measured.
Findings / Results: Thirty-eight patients with an average VAS of
58 (±13.8) during rest and 75 (±5.0) during
activities and 38 healthy controls were
included. MRI changes were common in
both groups, whereas, the summation of the
lumbar Pfirrmann’s grades (LDD score) was
significantly higher in the patients (MD:1.44
, CI:0.80 to 2.10; P <0.001). The patients’
lumbar lordosis angle was lower than that of
the controls for both the supine (MD:-6.4,
CI:-11.4 to -1.3; P=0.014) and standing
position (MD-5.6, CI -10.7 to -0.7; P=0.027).
No difference was found for supine-to-
standing lordosis changes (MD:0.8, CI: -1.8
to 3.3; P=0.57) between groups. The LDD
score was not correlated with the standing
or supine lumbar lordosis, but with the
supine-to-standing lordosis change in the
controls (Pearson: r = -0.54, P< 0.001).
Conclusions: Patients with LBP have a tendency to
reduce the lumbar lordosis, presumably to
reduce pain. In individuals without LBP age
related disc degeneration seems to lead to
increased lordotic stiffness.
66. Return to work after lumbar disc surgery is related to the duration of symptoms.
Carsten Ernst, Mikkel Andersen, Jesper Rasmussen, Søren Dahl
Sector for Spine Surgery and Research, Lillebaelt Hospital, Middelfart, Denmark; Department of Occupational Medicine, Hospital of South West Jutland, Esbjerg
Background: Lumbar disc herniation (LDH) is associated
with great morbidity and significant socio-
economic impact as the majority of the
patients are in the working age.
Purpose / Aim of Study: The purpose of this study is to investigate if
the return to work rate after lumbar disc
herniation surgery are affected by the
duration of symptoms and length of sick
leave.
Materials and Methods: The present study was conducted as a
single center study. All LDH patients who
underwent surgery at Lillebaelt Hospital from
June 1, 2009 through to December 31 were
included. Data were prospectively collected
in the database DaneSpine. Questions in
DaneSpine include preoperative duration of
leg pain, duration of preoperative sick leave
and working status one year post
operatively.
Findings / Results: Totally, 1329 patients were operated.
Overall 62 % of the patients were back to
work one year post-operatively. The rate of
patients returning to work decreases
significantly with the duration of leg pain.
Among the patients on sick leave prior to the
surgery 80 % returned to work if surgically
treated within 3 months whereas 46 %
returned to work with sick leave extending 3
months.
Conclusions: The present analysis suggests that the
return to work rate after lumbar disc
herniation surgery are affected by the
duration of symptoms and length of sick
leave. Detailed analysis with proper
adjustment for confounding factors and a
more accurate detection of disease
duration after surgery is necessary in
order to provide a more reliable
assessment of the preoperative disease
durations impact on return to work rate.
67. A Novel Cobalt Chromium Four-Rod Surgical Technique Reduces Motion and Rod Strain Compared to Standard Constructs Following Spinal Deformity Correction: an in vitro Biomechanical Study
Dennis Hallager Nielsen, Martin Gehrchen, Benny Dahl, Jonathan Harris, Manasa Gudipally, Brandon Bucklen
Spine Unit, Dept. of Orthopaedic Surgery, Rigshospitalet, University of Copenhagen; , Globus Medical, Inc., 2560 General Armistead Ave, Audubon, PA 19403, United States of America
Background: Surgical treatment of adult spinal deformity is
associated with a 20-30% revision rate; often
caused by rod breakage at the level of the lumbar
pedicle subtraction osteotomy (PSO). Only a few
small clinical studies with ambiguous results have
been reported regarding strategies to reduce
revision rate.
Purpose / Aim of Study: To assess the biomechanical effects of cobalt
chromium (CoCr) vs. Titanium (Ti), the addition of
two short pre-contoured rods across the PSO (4-
Rod) to the standard construct (2-Rod), and
supplemental interbody spacers (S) adjacent to the
PSO-level, on rod strain in a biomechanical model.
Materials and Methods: Five human specimens (T12-S1) underwent PSO at
L3 with posterior pedicle screw stabilization from L1-
S1. The final lordosis of all specimens was 70º.
Specimens were subjected to 10 Nm in flexion-
extension (FE), lateral bending (LB) and axial
rotation (AR) on a custom motion simulator. Linear
strain gauges measured surface rod strain during
FE motion at the PSO site. Lateral interbody
spacers were inserted at L2-L3 and L3-L4 following
initial testing of the primary rods. Repeated
measures ANOVAs assessed differences between
constructs in range of motion (ROM) and strain;
three-way repeated measures ANOVAs assessed
effects of construct factors.
Findings / Results: CoCr 4-Rod+S constructs provided the most strain
reduction compared to standard Ti 2-Rod (76%,
p=0.003). Additional rods significantly reduced FE
ROM (0.8%, p=0.021) and strain on the primary
rods, irrespective of construct (49%, p<0.001). CoCr
rods reduced strain (28%, p<0.001), but did not
affect ROM in any direction (all p>0.145). Interbody
spacers did not significantly reduce strain (6%,
p=0.318) or ROM in any direction (all p>0.091).
Conclusions: Additional short rods and the use of CoCr rods
significantly reduce primary rod strain across the
PSO site.
68. No effect of TLIF over standard posterior instrumented fusion.Results from a RCT 5-10 years follow up.
Kristian Høy, Kamilla Truong , Thomas Andersen, Cody Bünger
Ortopedic Department E, Spine Section, Aarhus University Hospital
Background: Inter-body fusion as a ALIF procedure
has earlier been in favour to a
standard procedure in long-term follow
up..
Purpose / Aim of Study: In order to show a similar trend we
made a 5-10 year follow up of your
randomized trail, between TLIF and
Instrumented Posterolateral fusion.
(PLF)
Materials and Methods: During 01.11.2003-.01.11.2008 100
pat`s were prospectively randomized
to TLIF or PLF. TLIF´s was operated
using TSRH (Medtronic) and Implex
(Zimmer), allograft. PLF`s using TSRH,
allograft. Inclusions: segmental
instability, disc degeneration, former
disc herniation, spondylolisthesis < 2.
Functional-outcome was registered,
prospectively, at 5-10 years, Dallas
Pain questionnaire (DPQ), SF-36, Low
Back pain questionnaire (LBRS), ODI.
At follow up a new MRI and X-ray was
done.
Findings / Results: Overall follow up was 93% of available,
94%, (44) in the PLF´s and 92 %, (44)
in the TLIF´s no difference. Mean
follow up was 8.6 years (5-10 years).
Mean age at follow up was 59 years
(34-76 years). Reoperation rate in a
long-term perspective was 14 % in the
TLIF´s and 14 % in the PLF´s.
According to LBPRS: Back was pain
was 3.8 (Mean), TLIF (3.65) PLF
(3.97), Leg pain 2.68 (Mean) 2.90
(TLIF) and 2.48 (PLF) no difference. At
follow up, no difference in functional
outcome DPQ, ODI, SF-36. When
asked after 8.6 years, if they would go
through the operation, with now a
day’s knowledge, 76% answered yes
75% (TLIF) and 77 %( PLF).
Conclusions: In a long-term perspective inter body
fusion with TLIF does not seem to
improve functional outcome in ODI, SF-
36, Dallas pain Questionnaire, Low
back pain rating scale compared to a
standard Instrumented posterolateral
Lumbar fusion (PLF).
69. Is it worthwhile operating geriatric patients with herniated lumbar disc?
Marie Nørgaard Petersen, Christian Støttrup, Mikkel Østerheden Andersen
Rygkirurgisk Sektor, Sygehus Lillebælt, Middelfart
Background: Throughout the modern world the mean age
is increasing, making the geriatric
population an even greater part of our
population. In many aspects, this population
differs from the general population, which
mandates altered approaches to many
issues within the healthcare system.
Disc herniation is a significant health issue
in our society, which also includes the
geriatric population. However limited studies
have been conducted on a geriatric-only
basis, for what reason we do not know
whether surgical intervention have similar
effects as is the case with general
population.
Purpose / Aim of Study: Does geriatric patients with lumbar disc
herniation (LDH) have significant effect
following surgical intervention measured
using patient reported outcome measures
(PROM).
Materials and Methods: 118 (53 male ; 65 female) patients ranging
70-90 years were operated for LDH at
Center for Spine Surgery and Research,
Middelfart, from June 6th 2010 till April 1st
2014. Using pre-operative and 1-year
follow-up data outcome was evaluated in
terms of PROMs (ODI, VAS, EQ-5D, SF-
36).
Findings / Results: Patients reported a significant improvement
in all measured PROMs at 1-year follow-up.
Mean ΔVAS-leg 3.1 (p <0.01), mean ΔVAS-
back 2.6 (p <0.01).
Mean ΔODI 29.7 (95% CI 25.2 ; 34.1) post-
operative mean of 16.0 and a p-value of
<0.01.
SF-36 Mental Component Score mean
improvement 12.0 (p <0.01) and Physical
Component Score mean improvement 5.2
(p 0.0001).
EQ-5D mean difference of 0.51 (p <0.01).
Conclusions: Geriatric patients have both statistically and
clinically significant improvements in
multiple PROMs following surgical
intervention for LDH. Incidence of surgical
complications was not found to be higher
when compared to general population.
When conservative therapy fails, surgical
intervention seems to be a good alternative
for geriatric patients suffering from LDH.
70. Comparison of synthetic bone graft ABM/P-15 and allograft on unistrumented posterior lumbar spine fusion in sheep
Martin Glasdam Axelsen, Stig Mindedahl Jespersen, Søren Overgaard, Ming Ding
Department of Orthopedic Surgery, Institute of Clinical Research, Odense University Hospital, University of Southern Denmark; Department of Orthopedic Surgery, Odense University Hospital
Background: Posteriolateral fusion (PLF) is a common
used procedure in spinal surgery. New
bone graft materials are wanted due to
limitations and side effects associated
with allo- and autografts.
Ifactor flexTM is a commercial available
synthetic bone graft material that has
gained CE approval in Europe. It
consists of a synthetic Anorganic bone
matrix (ABM) coated with a 15 amino
acid peptide sequence, identical to the
biding site for α2-β1 integrin on the
surface of bone forming cells. ABM/P15
bone graft has previously shown
promising bone formation properties
when used in closed devises or bone
defects. In PLF the lack of external
stability and the large graft size makes it
one of the most challenging grafting
procedures done in humans
Purpose / Aim of Study: To report fusion rates when using ABM/P15
in uninstrumental posteriolateral fusion in
sheep compared with allograft
Materials and Methods: Twelve sheep underwent open two level
uninstrumented PLF at L2/L3 and L4/L5.
Levels were randomised to allograft of
ABM/P15. The sheep were sacrificed after
4.5 months. Levels were harvested and
evaluated with Micro-CT 50 scanner and
qualitative histology. Fusion rates were
assessed with 2D sections and 3D
reconstruction images and fusion was
defined as intertransverse bridging
Findings / Results: In allograft group we found 68% fusion
rates. In ABM/P15 we found extensive
migration of the material in all sheep and a
fusion rate on 37%. These groups are
significant different (P <0,01). Qualitative
histology showed good osteointegration of
the material and good correlation to
scanning results
Conclusions: In this preclinical study we have proved that
ABM/p15 has the ability to migrate when
lacking external stability as in
uninstrumental PLF. This migration causes
lower fusion rates. These finding are
important for surgeons to make their choice
of graft material for PLF
71. Pharmacokinetics of Single Dose Cefuroxime in Porcine Intervertebral Disc and Vertebra Determined by Microdialysis
Pelle Hanberg
Ortopædkirurgisk Forskning i Aarhus, Aarhus Universitetshospital
Background: Pyogenic spondylodiscitis is associated with
prolonged antimicrobial therapy and high
relapse rates. Nevertheless, tissue
pharmacokinetic studies of relevant
antimicrobials are still sparse. Previous
approaches based on bone biopsy and
discectomy exhibit important methodological
limitations.
Purpose / Aim of Study: Microdialysis (MD) was used to assess
intervertebral disc (IVD), vertebral and
subcutaneous tissue (SCT)
pharmacokinetics of cefuroxime in a large
animal model.
Materials and Methods: Ten female pigs were assigned to receive
1,500 mg of cefuroxime intravenously over
15 min. Measurements of cefuroxime were
obtained from plasma, SCT, the vertebra
and the IVD for 8 hours thereafter. MD was
applied for sampling in solid tissues.
Findings / Results: For both the IVD and the vertebra, the area
under the concentration-curve from zero to
the last measured value was significantly
lower than that of free plasma. Tissue
penetration of cefuroxime was incomplete
for the IVD, while vertebral cefuroxime
penetration only just failed to be significantly
incomplete. Furthermore, the penetration of
cefuroxime from plasma to IVD was
delayed. Additionally, a noticeable
prolonged elimination rate of cefuroxime in
the IVD was found. The maximal
concentration and the elimination of
cefuroxime were reduced in IVD compared
to both SCT and vertebra. Due to this delay
in elimination of cefuroxime, the time with
concentrations above the minimal inhibitory
concentration (T>MIC) was significantly
higher in IVD than in SCT, vertebra and free
plasma for MICs up to 6 μg/ml.
Conclusions: MD was successfully applied for serial
assessment of the concentration of
cefuroxime in the IVD and the vertebral
bone. Penetration of cefuroxime from
plasma to IVD was found to be incomplete
and delayed, but due to a prolonged
elimination, the best results regarding
T>MIC was found in IVD.
72. Can supine lateral bending radiographs predict the initial in-brace correction of the Providence orthosis in patients treated for adolescent idiopathic scoliosis?
Søren Ohrt-Nissen
Spine Unit, Department of Orthopaedic Surgery, Rigshospitalet, University of Copenhagen
Background: Supine lateral bending radiographs (SLBR) are used
to assess curve flexibility in patients undergoing
surgical treatment of Adolescent Idiopathic Scoliosis
(AIS) but to what extent SLBR can be used to predict
in-brace correction (IBC) before initiating bracing
treatment is unknown. The Providence orthosis is a
part-time bracing system that has been shown to
provide substantial curve correction.
Purpose / Aim of Study: To determine the association between SLBR and
initial IBC in patients treated with Providence
orthosis.
Materials and Methods: A retrospective cross-sectional study was
conducted on all patients with AIS treated with
Providence orthosis from January 1st 2006 to
December 31st 2013. Only patients with a major
curve of 25-45° were included. Cobb angles on
SLBR before treatment and on initial standing, in-
brace radiograph (IBR) were measured twice for
each patient by one observer 30 days apart. Using a
repeated measures mixed effect model, mean
difference and 95% limits of agreement (LOA)
between Cobb angles on each type of radiograph
were estimated.
Findings / Results: A total of 127 patients were included. Median Cobb
angle on “pre-treatment” standing radiographs was
35° (IQR: 31-39°), which was reduced to 14° (IQR:
7-19°) on IBR. 52% of curves were thoracic (T),
30% were thoracolumbar/lumbar (TL/L) and 18%
were double curves (DC). Overall mean difference
between SLBR and IBR was 0.2° (LOA, ±10
degrees), for T curves it was 0.16° (LOA: ±8.4°), for
TL/L 0.9° (LOA: ±9.8°) and for DC 0.4° (LOA: ±16°).
Conclusions: Major curve measurements on SBLR and IBR are
within ±10° in T and TL/L curves with a mean
difference of less than one degree. These findings
could indicate that SBLR are not necessary prior to
brace treatment. This may reduce the number of
radiographs in patients with AIS.