1
Q
Orthotic Goals
A
- Correction
- Accommodation
- Stabilize
- Reduce Pain
2
Q
Correction
A
- Flexible deformity
- Restore follower load
- Reduce moment
- Measure correction by measuring Cobb angle
3
Q
Accommodation
A
- Fixed Deformity
- If you have a deforming moment, it is likely going to progress
4
Q
Stabilization
A
- Local Stabilization
- Limit gross vertebral sway (ADLs)
- Decrease moment and increase carrying capacity
5
Q
Reduce Pain
A
- Pain index scale
- Visual analog scale
6
Q
Free orthosis
A
Orthosis is not impairing any motion control whatsoever
** Elastic binder
7
Q
Stop orthosis
A
Part of the plane allows motion to occur, but the other part of the motion is stopped
** ex: specifically stopping extension but allowing flexion
8
Q
Hold orthosis
A
- Limiting motion throughout the entire plane
- Ex: Burst fracture: greatest instability is transverse plan bc all soft tissue is on lax and you’ll have a lot of available rotation
9
Q
Hold-Variable Orthosis
A
- Typically for transverse plane; “way out;” not a “true” hold
- allows micro movement within the orthosis
10
Q
Biomechanics Principles of Spinal Orthoses
A
- End-point control
- Total contact
- Three point pressure system
- Kinesthetic reminder
- Increased Intracavitary pressure
11
Q
End-Point Control
A
- Euler’s Theory
- Motion control of a free body
- Ultimately trying to increase the stability of a column (spine)
- Critical load: upper limit of load that the spine can withstand before bending
- When the critical load is less, the chance of progressing is greater
- The stable base is the pelvis
- The longer the length, the more stability we can impart
*** See the slide for critical load
12
Q
How End-Point Control Applies
A
- If you saw a 10% increase in height for a given curve magnitude, you will automatically see a 20% decrease in critical load/spinal stability
- Gotta get something on that spine to restore stability
13
Q
Total Contact
A
- Pressure = Force/Area
- You have to be able to re-distribute pressure to get aggressive stability –> if you don’t, you get skin breakdown
14
Q
Three- Point Pressure
A
- 2 pressures going in an equal and opposite direction of the third (in between the two)
- Trying to limit motion
- Trying to encourage person to withdraw from a stimulus
- Used for someone who has a compression
15
Q
What is the problem with 3 point pressure system
A
- Middle point (the opposite point) bc of a higher sheer to moment ratio right where the fracture is
◦ May address alignment but causes pain
16
Q
What does the alternative 3 point pressure system have
A
- Bending Moment
17
Q
Kinesthetic Reminder
A
- Kinesthetic
- Intact righting reflex
- Free orthotics help impart a kinesthetic reminder to withdraw from stimulus
- Will tell you if a design is indicated or contraindicated
18
Q
Increased Intra-cavitary Pressure
A
- Trying to reduce discal pressure
- History: controversial bc they didn’t measure interstitial pressure
- can decrease discal pressure but not really sure what the mechanism is (is the orthosis creating load sharing?)
19
Q
Optimal Sagittal Position
A
- Lumbar (hyper) extension for burst fracture, compression fracture, seatbelt fracture, disc herniation
- Lumbar flexion for spondylolysis, spondylolysthesis, central or lateral stenosis to reduce pressure on nerve roots
20
Q
Cast Syndrome
A
Anything where you have a loss of extension or lordosis that draws superior mesenteric artery to the duodenum thus blocking it
21
Q
Corset materials
A
- canvas
- cotton mesh
- elastic
22
Q
Corset closures
A
- snap
- hook and eye
- pull straps/velcro
23
Q
What is important to do with patients using a corset?
A
Need to watch them don and doff the device to ensure they can tighten it enough
* typically used by older patients, so arthritis may prevent them from putting it on properly
24
Q
Biomechanical principles of corsets
A
- total contact
- kinesthetic reminder
- increased intracavitary pressure
- modified three point pressure system
25
Corsets - pathologies
- muscle strain
- post-surgical
- low back pain
- maternity (elastic in the front)
** pretty rare post-op
26
Research on corsets says:
- Least effective spinal orthosis for limiting gross trunk motion when compared to other devices
- Effects of reducing myoelectric activity in the paraspinal musculature has inconsistent results and needs further investigation
27
Components of contact spinal systems
- Kydex
- Polyethylene
- Copolymer
28
Openings of total contact spinal systems
- Overlapping
- Interlocking
- Posterior-opening
- anterior-opening
* often 2 piece because it is easier to don
29
Total contact spinal systems - biomechanical principles
- three point pressure
- end point control
- kinesthetic reminder
- increased intracavitary pressure
30
At what angle do we see significant axial load on the spine
30 degrees or higher
31
Total contact spinal system - donning/doffing
- in supine to reduce axial load of the spine
32
Sequence for tightening the straps of total contact spinal system
* Lay the person down before tightening can reduce the deformity
* Start with inferior strap to lock the orthosis onto the pelvis
◦ Facilitates better end point control
◦ Less problems with orthosis migrating up into axilla
* Work up to the top strap
* Wait a few minutes for disco-elastic change
* Go back to bottom strap
33
Post surgical
- internal construct
- healing
- pain reduction
34
Do patients s/p idiopathic scoliosis get orthoses?
Not often because integrity of other structures is good
* typically used for neuromuscular scoliosis
35
If internal construct fails from scoliosis surgery, what motions is it typically from?
flexion and rotation
36
What gender does idiopathic adolescent scoliosis affect most?
Females > males (4:1)
37
Progression indicators for idiopathic adolescent scoliosis
◦ Skeletal maturity
‣ The more skeletally immature, the more likely it will progress
‣ Menarche to 18 mo later is typically the time of maturity cessation
◦ Magnitude of the curve
‣ Bigger the curve, the more likely it is going to progress
38
Orthoses options for idiopathic adolescent scoliosis
TLSO
CTLSO
39
TLSO is most effect for what?
curve apex T7 and below
- axilla limits how high you can bring it up
40
Types of data acquisition
- casting
- scanning: sit or lay down in a frame, get into corrected position then scan
41
What degree range is typically the curves that orthoses can help?
25-45 degrees
42
Mechanism to manage curves for idiopathic adolescent scoliosis
- curve correction
- end point control
- transverse load
* As degree of curvature increases, stability decreases
* 60 degree curve = almost no stability at all to the spine = not much we can do from an orthotics stand point
◦ Still likely to progress
◦ Likely need surgery
* Looking for 60-70% correction in the brace
◦ When they stop using it, it progresses again until they reach skeletal maturity
43
Window for orthotic management
◦ Curve is very steep
◦ 30 degree curve is at 50% stability
‣ But if we can decrease it down to 20 degrees, we increase that stability to 80%
44
BRAIST Study Results
* 75% of subjects that wore an orthosis did not require surgery compared to only 42% in the observation group that did not require surgery
45
Wearing the orthosis BLANK hours per day is the same as not wearing an orthosis
0-6 hours/day
46
Wearing the orthosis greater than BLANK hours a day is overkill
>18 hours/day
47
BRAIST primary study conclusions
* Bracing significantly decreased progression in high risk curves in AIS to the threshold of surgery
* Gains in benefit were seen with increasing hours of brace wear
** Dosage is the variable that had the greatest impact
48
Greatest influence on patient compliance regarding wearing of the orthosis
* Difficulty paying attention in school
* Emotional about having to wear orthosis
* Problems with eating
* Difficulty in sitting
* Breathing
* Look worse in clothes
49
Neuromuscular Scoliosis
- Can't really change it.. trying to delay surgery
- Trying to restore overall balance
- Prevent curve from getting worse and improve physiologic function and ADLs
50
Review Spondylolisthesis
51
Review Burst Fracture
52
3 region coupling system
* Purely a bending moment, taking away the shear
* Decreases pain
* Great for kyphosis as well
