Spinal Orthotic Biomechanics

Question 1

A 20 year old male has sustained an L1 burst fracture - What do you recommend?

Answer 1

TLSO: Triplanar control

Question 2

Which orthosis would be indicated for a T9, 2-column compression fracture?

Answer 2

TLSO: sagittal/coronal control

Question 3

Which orthosis would you recommend to manage an anterior compression fracture at T12?

Answer 3

TLSO: sagittal control

Question 4

A patient presents with disruption of the supraspinous ligament, posterior longitudinal ligament and the ligamentun flavum. What is most likely the mechanism of injury?

Answer 4

Flexion

Question 5

When the anterior longitudinal ligament is involved, what is the most common mechanism of injury?

Answer 5

Extension

Question 6

The correct anterior pin placement for a HALO is:

Answer 6

10mm superior to the eyebrow and placed above the lateral 1/3 of eyebrow

Question 7

An adolescent female with scoliosis presents in your facility. Because she is being recommended for orthotic treatment, what presentation would you expect to see?

Answer 7

Risser sign of +1-2, Cobb angle of 25-40 degrees

Question 8

Orthotic management of a T1 fracture should be treated with:

Answer 8

A CTO

Question 9

What is the correct posterior trim line for a thermoplastic TLSO?

Answer 9

10 mm distal to spine of the scapula

10 mm above the seat with hips flexed to 90 degrees

Question 10

Which biomechanical principle would be the most effective in unloading an intervertebral disc?

Answer 10

Increased intra-cavitary pressure

Question 11

List, in order from least to most effective, the following cervical orthoses: SOMI, 4-poster CTO, Miami J, HALO and soft collar

Answer 11

Soft collar, Miami J, SOMI, 4 poster CTO and HALO

Question 12

Which condition should be positioned in sagittal flexion for orthotic treatment?

Answer 12

Spondylolisthesis, Spondylolysis and Spinal Stenosis

Question 13

When is it acceptable to have the aterior apron on a conventional LSO to be shorter than the desired height?

Answer 13

Spondylolysis, Spondylolisthesis, or any condition that you treat with sagittal flexion

Question 14

Unilateral contracture of the sternocleidomastoid that is indicative of torticollis would cause the patient to present with:

Answer 14

Lateral head flexion to ipsolateral side and rotation to the contralateral side

Question 15

Placement of a thoracic band on a conventional LSO should be:

Answer 15

10mm distal to inferior angle of the scapula

Question 16

What is the most important biomechanical principle when managing a neuromuscular spine?

Answer 16

Total contact

Question 17

Why is a SOMI not effective in controlling cervical extension?

Answer 17

The occipital pad pivots in the sagittal plane and the design does not have enough rigidity to control cervical extension

Question 18

Can a three-column, two level injury be treated orthotically?

Answer 18

No, surgical stabilization will be needed prior to orthotic treatment

Question 19

Traumatic spondylolisthesis of C2 is known as:

Answer 19

Hangman’s fracture

Question 20

In what order should the HALO pins be tightened?

Answer 20

Diagonally opposed pins will be tightened together

Question 21

Increasing the intra-abdominal pressure is used in spinal orthotics to:

Answer 21

Reduce axial load on lumbar vertebrae and intervertebral discs

Question 22

What is the method used to find baseline for corset measurement?

Answer 22

(inferior costal margin to iliac crest)/2

Question 23

If a patient is unable to tolerate strap pressure in the axilla in a TLSO:sagittal control orthosis, what adjustment might be done?

Answer 23

Use a harness chest strap with a sternal plate

Question 24

Which cervical level exhibits the most sagittal motion?

Answer 24

The most motion occurs between the skull and C1

Question 25

The Knight orthosis is also known as:

Answer 25

LSO: sagittal/coronal control

Question 26

In what position should spinal orthoses be tightened on a patient?

Answer 26

Supine

Question 27

Where is the appropriate placement of the paraspinal bars for lumbosacral orthosis?

Answer 27

Follow the apices of the paraspinal muscles

Question 28

Why would a Milwaukee CTLSO not be recommended for a person with a paralytic spine?

Answer 28

Due to the lack of sensation, the individual cannot provide the active forces (kinesthetic reminder) necessary for correction

Question 29

Hypokyphosis is defined as having a sagittal curve magnitude in the range of:

Answer 29

0-20 degrees

Question 30

A 35 year old male is seen at the hospital with a compression fracture of L5. What is your treatmet recommendation?

Answer 30

LSO with unilateral hip spica attachment
Due to the increase motion that would occur with stabilizing L1-5, the hip spica is added to immobilize L5 for the fracture to heal without irritation.

Question 31

What is the most likely mechanism of injury for a seatbelt (chance) fracture?

Answer 31

Flexion and distraction

Question 32

Which is the only orthosis known to control motion at the atlanto-occipital joint?

Answer 32

HALO

Question 33

A patient is seen in the office for treatment of a grade III spondylolisthesis presentation and a 45 degree slip angle. What is the treatment recommendation for the patient?

Answer 33

Surgery