Clinical Results - 2002
1. SPINECOR PATIENTS INITIAL COHORT
At
Table
1 : Initial Characteristics of Idiopathic Scoliosis Patient Population
|
|
Initial
Cobb Angle (Deg) |
Cobb
Angle Minimum During Treatment |
Percent
Reduction |
||||
|
n |
Mean |
Stdev |
Mean |
STdev |
Mean |
STdev |
|
|
All
Patients |
195 |
29 |
8 |
18 |
10 |
38 |
26 |
|
Less
than 30° |
115 |
23 |
5 |
13 |
8 |
45 |
28 |
|
Greater
than 30° |
80 |
36 |
4 |
26 |
8 |
28 |
20 |
At the last available visit there were 109
patients still under treatment with a mean treatment time of 1.5 years (SD: 1
year), and 71 have terminated treatment with a post treatment follow-up time
ranging from 0 to 4.5 years. From this cohort of 195 patients, there were
8 patients who progressed to surgery. The patients who progressed to
surgery had an initial mean Cobb angle of 34° (SD:5°), with a mean end of
treatment Cobb angle of 45° (SD:6°) after 2 years (SD:1 year) of
treatment. There were also 15 patients who withdrew from treatment after
a mean of 1.2 years (SD: .72 years).
2. Outcome for Idiopathic Scoliosis Patients with a Minimum 2-year Follow-up
After Treatment with the SpineCor System
For the patients who have completed
treatment there are 29 who had a minimum follow-up time of 2 years (mean 29
months SD : 4 months). The initial Cobb angle for this sub-cohort of patients
was 29º (SD:7º), and after 3 months of treatment the mean Cobb angle was 19º
(SD:11º) corresponding to an overall mean decrease of 10º (SD: 5º)
representing a reducibility of 40% (SD: 28%). At the end of
treatment (time=24 months; SD 9 months; Risser 3 or
4) the mean Cobb angle was 21º (SD:12º). At this time there were 61% of
the patients who maintained the initial correction obtained at three months,
with 35% aggravating and 4% improving. The mean Cobb angle at 2 years
follow-up was 24º (SD:11º), where 66% maintained their end of treatment Cobb
angle, 6% improved and 28% worsened.
At 2 years follow-up there was an overall correction in reference to the
patients initial state of greater than 5° for 55% of the patients (mean:
10°; range: 6° (16%) to 15° (83%)), there was a stabilisation
for 38% (mean: 2° (9%); range -3° (19%) to 5° (25%)) and 7% of the patients
worsened, (mean: -8° (31%); Range: -6° (-17%) to -10° (-33%). The evolution
during treatment for the improved, stabilised
and aggravated patients are presented in Figure 1.
Figure 1:
General Treatment Trend
For the 29 patients that
had a minimum 2-year follow-up a repeated measures analysis of variance was
performed, comparing the initial state, 3months in brace, end of treatment, 1
year and 2 years follow-up. Since this is a preliminary analysis of an
initial cohort of 29 patients, a significance level of p<0.01 was
chosen. There was a significant difference between the initial condition
and 3months (10°±5°), end of treatment (7°±7°) as well as follow-up 1 and 2
years (4°±7° and 5°±7°, respectively). There was no difference between 3
months and end of treatment (-3°±8°), and follow-up 1 year (-6°±7°), but
a difference between 3 months and the 2 year follow-up
(-5°±7°). At the end of treatment there was no difference
with follow-up 1 year (-3°±6°), and 2 years (-2°±5°), as well as between 1 and
2 years follow-up (1°±4°). (See Table 2 and Table 3).
Table 2: Difference between each time
interval during the course of treatment with the SpineCor
System and during follow-up.
|
|
Initial
3M,ET,1Y,2Y |
3M-ET,
1Y, 2Y |
ET-1Y,
2Y |
1Y -
2Y |
||||||
|
|
3M |
ET |
1 Year |
2 Year |
ET |
1 Year |
2 Year |
1 Year |
2 Year |
|
|
All |
10 (5) |
7 (7) |
4 (7) |
5 (7) |
-3 (8) |
-6 (7) |
-5 (7) |
-3 (6) |
-2 (5) |
1 (4) |
|
Improved |
12 (4) |
10 (6) |
8 (5) |
9 (3) |
-2 (4) |
-4 (5) |
-2 (3) |
-2 (7) |
-1 (5) |
2 (5) |
|
Stable |
7 (6) |
5 (5) |
0 (3) |
1 (3) |
-2 (9) |
-6 (5) |
-5 (7) |
-4 (6) |
-4 (6) |
1 (3) |
|
Aggravated |
10 (3) |
-7 (1) |
-13 (1) |
-13 (1) |
-17 (1) |
-23 (1) |
-23 (1) |
-6 (0) |
-6 (0) |
0 |
Table 3: Repeated measures analysis of
variance for patients with a minimum follow-up of 2 years.
|
Conditions |
P
Value |
P<0.01 |
|
Initial vs Three Months in Brace |
p= 0.0000 |
* |
|
3 Months
vs End of Treatment |
p = 0.0135 |
|
|
End of
Treatment Follow-up 1 Year |
p = 0.999 Þ |
|
|
Follow-up
1 Year vs 2 Years |
p = 0.999 Þ |
|
|
Þ
Note: The comparison between end of treatment and follow-up 1 year and 2
years indicates that there is no worsening of the curve during the
post-treatment follow-up period. This is in contrast with most rigid
brace. |
||
3. Survival Analysis of Patients
Treated with the SpineCor System
A
survival analysis as utilised by Nachemson
et al., 1995 was performed on the cohort of patients treated with the SpineCor system. The cohort of patients was divided
according to the amplitude of the initial Cobb angle such that group 1 (G1)
consisted of patients with a Cobb angle less than 30° and group 2 (G2)
consisted of patients with a Cobb angle of greater than 30°.
A
change in the Cobb angle at the end of treatment and/or the last available
visit in reference to the initial visit was utilised
to identify a correction (decrease of more than 5°), a stabilisation
(change of ±5°), or aggravation (increase of more than 5°). Criteria for
success was defined as a correction or stabilization of the Cobb angle, and
failure as an aggravation of the Cobb angle.
With
the initial visit as a reference point a survival curve was constructed for the
patients that are still under treatment in addition to the withdrawal
patients. The probability of obtaining a positive treatment effect
increased as the duration of treatment increased for both groups of patients,
with 95% confidence intervals of .84-1.0 and .80-.99 at 3 years of treatment in
brace.
For
the patients that have completed treatment the cumulative probability of
success at 4 years follow-up (combined treatment time and post treatment
follow-up time) had 95% confidence intervals that were 0.82 to 1.0 and .71 to
1.0).
A
survival curve was also constructed for the patients who have completed
treatment using the end of treatment status as the reference point vs the last available follow-up visit post-treatment as
reference points. The confidence intervals for the cumulative probability
of success at 2 years post-treatment follow-up was 0.71- 0.98 to 0.62-1.0 for
groups 1 and 2 respectively.
4. Interim Results of a
Prospective Randomised Study of the Natural History
of Idiopathic Scoliosis VS Treatment with The SpineCor
Brace
The
objective of this prospective randomised study was to
compare the natural history of Idiopathic Scoliosis patients to those treated
with a SpineCor brace with a Cobb angle between 15
and 30 degrees. A cohort of 65 patients were randomly assigned to a
control non-treated (n=36; age=12 years; Cobb angle:20±5 degrees) or treated
group with the SpineCor brace (n=29; age=12
years; Cobb angle : 22±5 degrees). Inclusion criteria included an initial
Cobb angle between 15 and 30 degrees, Risser 0, 1 or
2, high risk of progression (increase of Cobb angle of 5 degrees or more within
the last 6 months), girl or boy and no significant malformation of the spine.
Each patient underwent a comprehensive evaluation (radiological and clinical)
prior to commencing the study, at 4 month intervals during treatment and
follow-up. From both groups there were 3 patients who withdrew. For
the remaining 33 control subjects there was a mean Cobb angle of 26±8
degrees and for the treated group, 20 are still in treatment with a mean
Cobb angle in brace of 15±7 degrees. The remaining 6 patients, in the treated
group, have been weaned from the brace but for less than 1 year.
Table 4: Percentage of Patients Improved, Stable and Worsened at the
Last Available Visit
|
|
Improved |
Stable |
Worsened |
|
Control
(n=33) |
12 |
36 |
52 |
This is the first prospective randomised study on Scoliosis patients investigating the
Cobb angle between 15 and 30 degrees. This interim evaluation reveals a
strong tendency where 52 percent of the control group worsen, compared to the
treated group who showed a worsening of only 5 percent. This interim
result, which shows this large difference in worsening between treated and
non-treated patients, questions the logic of continuing this prospective randomised study.
5. SpineCor Patient Treated Worldwide
The SpineCor
system is currently being used at
