8- Lumbar Spine Flashcards
_____% of persons in industrialized countries with have LBP at some point in their lives.
70%
One-year prevalence of LBP is _____% and peak prevalence occurs between ______ and _____ years old.
15-45%
35-55 years
____% of patients with acute LBP will self-resolve within 6 weeks.
____% of people develop chronic pain
90%
2-7%
Recurrent and chronic pain accounts for _____ % of total worker’s absenteeism
75-85%
What is the estimated annual US worker’s compensation costs for LBD?
$8.8 billion
What is the strongest predictor of further incidence of LBP?
history of previous episodes
About ___% of people seen with LBP in primary care have compression fractures and about ____% have neoplasm.
4% compression fractures
1% neoplasm
What is the prevalence of prolapsed IVD?
1-3%
When are bulging discs common (age-wise)?
20-39 yo and 60-80 y.o
When are disc herniations more common (age-wise)?
as the patient ages
When is degenerative disc disease most common?
strongly related to aging
What is the approximate ROM for lumbar flexion?
40-50 degrees
What is the approximate ROM for lumbar extension?
55-70 degrees
What is the approximate ROM for lumbar axial rotation?
5-7 degrees
What is the approximate ROM for lumbar lateral flexion?
20 degrees
What are the proportions of 85 degrees of T-L flexion?
35 degrees thoracic, 50 degrees lumbar flexion
What are the proportions of 35-40 degrees of T-L extension?
20-25 degrees of thoracic extension, 15 degrees lumbar extension
What are the proportions of about 40 degrees of T-L axial rotation?
35 degrees thoracic, 5 degrees lumbar rotation
What are the proportions of about 45 degrees of T-L lateral flexion?
25 degrees thoracic, 20 degrees lumbar sidebending
What can large end plate fractures cause?
permit liquid NP to squirt through the end plate into the vertebral body
How do Schmorl’s Nodes form?
sometimes end plate fractures cause a local area of bone to collapse under the end plate, creating a pit or crater that gradually forms a Schmorl’s Node. (associated with spinal compression when the spine is in neutral)
What happens to the annulus fibrosis during end plate fractures?
it remains intact
What is the one-time loading shear tolerance of FSU reported to be?
about 2000-2800 N ranges
What does repeated, cyclic full spin flexion and extension lead to?
fatigue within the posterior arch, leading to a pars fracture (spondylolisthesis)
What is an appropriate rehab objective for patients with pars fractures?
stability (generally don’t tolerate ROM)
How are the collagen fibers of the annulus fibrosis arranged?
multiple concentric layers, with fibers in every other layer running in identical directions (orientation is about 65 from vertical)
What are the 3 major components of the IVD?
nucleus pulposus, annulus fibrosis, end plates
Why are the collagen fibers of the annulus fibrosis oriented the way they are?
they can also resist twisting force (but only 50% can function at a time during this)
What happens to the annulus fibrosis during compression when little hydrostatic pressure is present (like during an end plate fracture or herniation)?
The outer layers bulge outward and the inner layers bulge inward, causing laminae of AF to separate or delaminate (this can be the pathway for nuclear material to leak through lamellae layers and finally extrude)
How must the disc be oriented in order to herniate?
must be bent to full ROM in order to herniate
What is disc herniation associate with (mechanism)?
associated with repeated loading in range of thousands of times (implicating role of fatigue as injury mechanism)
What is disc herniation linked with?
sedentary occupations and sitting posture
What age are disc herniations associated with?
tend to occur in younger spines, those with higher water content, and more hydraulic behavior
What is it called when there is expansion of disc material beyond its normal border (eg., a normal disc during compression, or a degenerated disc with decreased disc height)?
Disc Bulge
What is is called when there is discrete localized bulge in the AF, the disc material is displaced (ie., the NP has protruded through the inner layers of the AF/a true herniation)?
Protrusion
What is it called when the NP has protruded through all layers of the AF, but remains attached to the disc of origin?
Extrusion
What is it called when a free disc fragment is located in the epidural space can migrate superiorly, inferiorly, medially, or laterally?
Sequestration
What ROM is damage to the annulus fibrosis of a disc (herniation) associated with?
fully flexing the spine for repeated or prolonged periods of time