The internal and external validity of each study was then
subjectively rated as
“high,” “moderate,” or “low” based on
the quantity and importance of threats present. As a guide,
for internal validity, 0 to 3 threats was rated
“high,” 4 to 6
threats as
“moderate,” and 7 to 13/14 threats as “low.” For
external validity, 0 to 2 threats was rated
“high,” 3 to 5
threats as
“moderate,” and 6 to 8 threats as “low.” Each
study was given an overall quality of evidence of
“high,”
“moderate,” and “low” outlined by the AAOP State-of-the-
Science Evidence Report Guidelines.
22
The overall ratings
from the AAOP State-of-the-Science Evidence Report Guide-
lines were used in assigning con
fidence to the developed
EESs described in the results section.
Empirical Evidence Statements
Based on results from the included publications, EESs were
developed describing ef
ficacy of the IDEO. Reviewers rated
the level of con
fidence of each EES as “high,” “moderate,”
“low,” or “insufficient,” based on the number of publications
contributing to the statement, the methodological quality of
those studies and whether the contributing
findings were
con
firmatory or conflicting.
22
RESULTS
In total, 375 articles were identi
fied from the search (Fig. 1).
Of these, 12 met inclusion criteria. Publication dates of the
12 included articles ranged from 2011 to 2015 with 6 pub-
lished in 2014. Half of the studies were observational and the
other half was experimental (Table I). No systematic reviews
or meta-analyses were identi
fied. Because of heterogeneity
in sample size and demography, methods, accommodation
periods, outcome measures and design, and meta-analyses
were not possible. Manuscripts were published predomi-
nantly in orthopedic trauma and biomechanical journals
(Table II).
Subjects
A total of 487 subjects were studied within all 12 manuscripts
(Table III). Only six females were reportedly studied.
14,16
One subgroup of amputees (n = 57) were included.
23
Uninjured, healthy subjects were recruited as controls in two
studies to provide reference values of unimpaired gait func-
tion in which to compare against. This accounted for 25 sub-
jects wherein both articles, reference groups
’ mean age was
23 years, mean height was 1.8 m, and the mean mass was
86 kg
24
and 87 kg
25
respectively. Conversely, control subjects
(n = 81), utilized in two other studies had experienced
HELET including volumetric muscle loss below the knee,
distal motor nerve injury, lower limb fracture, and other inju-
ries.
15,23
Of these 81 control subjects, 31 had a mean age of
30 years and received IDEO only as opposed to IDEO and
RTR training.
15
The remaining 50 of these subjects received
limb salvage and there were no reports of IDEO provision
nor anthropometry.
23
Of the total 487 subjects from all included studies, another
subgroup of 102 participants served as their own controls in
FIGURE 1.
Results of the literature search and application.
TABLE I.
Distribution of Included by Studies by Study Design
Study
Design Publications
S1
Meta-Analysis
0
S2
Systematic Review
0
E1
Randomized Control Trial
1
E2
Controlled Trial
2
E3
Interrupted Time Series Trial
1
E4
Single Subject Trial
0
E5
Controlled Before and After Trial
2
O1
Cohort Study
2
O2
Case
–Control Study
0
O3
Cross-Sectional Study
2
O4
Qualitative Study
1
O5
Case Series
0
O6
Case Study
1
X1
Group Consensus
0
X1
Expert Opinion
0
Total
12
TABLE II.
Distribution of the Studies per Journal
Journal
Number of
Publications
Clinical Biomechanics
1
Clinical Orthopaedics and Related Research
2
Gait and Posture
1
Journal of Biomechanical Engineering
1
Journal of Bone and Joint Surgery
1
Journal of Orthopaedic Trauma
2
Journal of Surgical Orthopaedic Advances
1
Journal of the American Academy of
Orthopaedic Surgeons
1
Journal of Trauma and Acute Care Surgery
1
Journal of Trauma, Injury, Infection and Critical Care
1
Total
12
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Outcomes Associated With the Intrepid Dynamic Exoskeletal Orthosis
repeated measure design protocols. They
first completed
preorthotic physical therapy. One group (n = 84) underwent
baseline assessment then received IDEO plus additional ther-
apy followed by post-assessment.
14
This group included
5 females and was described in the manuscript better from an
injury perspective than from a demographic perspective. The
remaining 18 randomized for repeated assessment with three
different orthoses including IDEO.
26
Finally, a total of 253 of the 487 subjects were studied as
experimental subjects. Eleven of the 12 studies reported age,
and
five5
24
–28
reported subject height and mass or body mass
index (BMI). Interquartile mean (range) for studies reporting
anthropometric data yields an age of 29.4 (1.7) years, height
of 1.8(0.02) m, and mass of 87.8(1.9) kg. Mean BMI was
28.5 kg/m
2
reportedly.
23
Diagnoses for subjects in the experi-
mental groups of studies included; open ankle fracture, knee,
or ankle ligamentous damage or instability; bone, muscle, or
other tissue loss; post-traumatic osteoarthritis; fractures of the
spine and upper extremity; burns; hip subluxation; lower
extremity motor nerve injury; ankle muscle weakness; neu-
ropathy; paresis; equinovarus; shrapnel presence; vascular
injury; ankle arthrodesis; reconstruction of the foot or ankle
and soft tissue trauma. Additionally, subjects with spinal cord
injury were provided IDEOs and physically assessed.
14,15
The
mechanism of injury for these diagnoses tended to include
HELET and more speci
fically causes such as motor vehicle
accidents, blast injuries, gunshot wounds, and falls.
Delayed Amputation and RTD
Seventy three patients initially requested amputation. Of
these, 13 continued to request or received an amputation fol-
lowing provision of an IDEO and RTR training. Among
these, there were no reports of RTD.
14,16,17,26
Conversely,
one study
23
reported that of 57 patients who received amputa-
tion, 7 (12.3%) RTD. Of 325 patients that received limb sal-
vage, 108(33.2%) returned to duty. Within these 325 cases,
one subset of 275 (84.6%) received an IDEO and a second
subset of 244 (75.1%) reportedly received an IDEO in combi-
nation with RTR therapy. From the
first subset, 96 (34.9%)
returned to active duty, whereas 92 (37.7%) from the second
subset returned to active duty.
1,13,15
–17,23
Internal Validity
The most prevalent threats to internal validity in this body
of literature include a lack of blinding, a lack of reporting
exclusion criteria, no reported consideration for fatigue and
learning, and no reporting of effect size (Table IV). The
overall assessment was blended with 5/12 of the studies
being rated as having low internal validity, 5/10 having
moderate-level internal validity, and 2/10 having high inter-
nal validity. Additionally, two studies had attrition greater
than 20% (22
–38%).
14,15
External Validity
All 12 studies had high external validity. The most common
threat to external validity across studies was a lack of describ-
ing the sample adequately. For instance, 7 of 12 studies did
not adequately describe the sample in terms of anthropometry
and demography.
Effect Size
Effect sizes were unable to be calculated in several of the
included studies. Five studies utilized either case report
methodology or descriptive outcomes, which are not condu-
cive to these calculations.
1,13,15
–17
Additionally, Harper et al
TABLE III.
Characteristics of Included Studies
Author (Year)
Study Design
Independent Variable(s)
Sample
Size
Mean
Age*
Outcome Measures
Overall Quality
of Evidence
Patzkowski et al (2011)
O6
IDEO + RTR
1
29
Return to Recreation and Duty
Moderate
Owens et al (2011)
O4
IDEO + RTR
10
28.8
Return to Recreation and Duty
Moderate
Patzkowski et al (2012)
O3
IDEO + RTR
16
28
Return to Function, Recreation
and Dutyd
Moderate
Patzkowski et al (2012)
O3
IDEO + RTR
17
31.4
RTD + Clinical Endpoints
Moderate
Patzkowski et al (2012)
E1
IDEO + RTR vs. Other Orthoses
18
31
Clinical Functional Performance
Outcome Measures
Moderate
Harper et al (2014)
E5
IDEO Strut Stiffness
13
29.4
LE Biomechanical Analyses
High
Blair et al (2014)
O1
IDEO + RTR
146
31.5
Return to Duty
Moderate
Bedigrew et al (2014)
E2
IDEO + RTR. Early vs. Late
Rehab Entry
84
NR
† Functional Performance Outcomes
and Perceptive Measures
Moderate
Esposito et al (2014)
E3
IDEO Strut Stiffness
26
29.4
LE Biomechanical Analyses
Moderate
Harper et al (2014)
E5
IDEO Strut Construction
10
28.7
LE Biomechanical Analyses
High
Sheean et al (2014)
O1
Hindfoot Reconstruction
(w/IDEO + RTR)
vs. Amputation
122
26
Return to Function, Recreation
and Duty
Moderate
Haight et al (2015)
E2
IDEO Strut Stiffness
24
29.3
LE Biomechanical Analyses
Moderate
IDEO, (Intrepid Dynamic Exoskeletal Orthosis; LE, Lower Extremity; NR, Not Reported; RTR, Return to Run. *Experimental subjects and age in years.
†Eligibility was aged >18 year.
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