MSK - Disorders of the Spine Part 2

what is the most common cause of back pain?

mechanical disorders of the back

what are examples of mechanical disorders of the back?

• muscle/ligament strain

• poor posture and overuse injuries

• osteoarthritis of the spine

• degenerative disk disease

• spondylosis

• disc herniation

what is one of the most common cause of cervical and lumbar back pain?

degenerative disc disorder

what describes degenerative disc disorder?

a chronic degenerative condition in which intervertebral discs undergo age-related biochemical and structural changes leading to disc dehydration, loss of disc height, reduced mechanical function, and possible pain or neurological complications

degenerative disc disorders are a part of what?

normal aging

• can be asymptomatic, incidental finding on imaging studies

what are the two parts of vertebra?

• thick, disc-shaped body anteriorly

• posterior arch with processes for muscle attachment + articulation with other vertebra

how are vertebral bodies connected?

by intervertebral (IV) discs and ligaments

joining vertebral arches forms what?

the intervertebral foramen

spinal nerves exit the vertebral column through what?

intervertebral foramen

what are functions of intervertebral discs?

• shock absorption

• load distribution

• flexibility, mobility of spine

• maintenance of vertebral spacing

what makes up the intervertebral discs?

• nucleus pulpous (inner)

• annulus fibrosus (outer)

what describes nucleus pulpous (inner)?

• gel-like structure

• rich in progeoglycans (aggrecan)

• acts as a shock absorber

• 70-90% water

what describes annulus fibrosus (outer)?

• concentric layers of collagen fibers

• provides strength

biochemical changes that lead to DDD cause what?

disc desiccation

what describes disc desiccation?

dehydration of IV disc due to loss of aggrecan and other proteoglycans

disc desiccation leads to what?

decreased shock absorption + increased mechanical stress → fragmentation of nucleus pulposus

normal aging can lead to what?

1. biochemical changes

2. structural changes

what describes structural changes that occur due to normal aging?

• decreased height

• annular fissures/tears

• rupture of annulus → herniation

rupture of annulus leads to what?

herniation

what happens when IV discs lose height?

narrowed opening for nerve and osteophyte formation that restrictions movement

what describes the degenerative cascade?

1. healthy disc

2. disc desiccation

3. loss of disc height

4. abnormal motion (spinal instability)

5. facet joint degeneration

6. osteophyte formation

7. spondylosis

8. spinal stenosis

9. nerve root/compression

what describes early deneration?

• often asymptomatic

• mild back pain

what describes moderate degeneration?

marked by loss of disc height

• back pain

• stiffness

• reduced flexibility

what describes advanced degeneration?

• radiculopathy

• sciatica

• cervical myelopathy

• functional disability

what are non-modifiable risk factors for DDD?

• aging

• genetic predisposition

• gender (males more commonly affected at younger age)

• any congentical spinal abnormality

what are modifiable risk factors for DDD?

• smoking

• obesity

• poor posture

• occupational loading

• repetitive trauma

• sedentary lifestyle

advanced progression of DDD presents as what?

• spondylosis

• spondylolisthesis

• disc protrusion and herniation

• spinal stenosis

what describes spondylosis?

progressive degeneration of the spine

• involvement of discs, vertebrae, facet joints, ligaments

• osteophyte formation

what describes spondylolisthesis?

injured vertebrae slip over each other

• disrupts normal alignment of the spine = instability, abnormal movement

what describes disc protrusion and herniation?

• over time, injured nucleus pulposus protrudes through the annular fibrosus

• tear in annulus = herniation

• impingement on nerves = radiculopathy or even myelopathy

what are clinical manifestations of cervical DDD?

• neck pain, stiffness, reduced range of motion (ROM)

• headaches

• shoulder pain

• radiculopathy

• myelopathy

myelopathy resulting from cervical DD can manifest as what?

compression of the spinal cord

• gait disturbances, loss of balance

• hand weakness, numbness

• uncoordinated reflexes (hyperreflexia (upper motor neuron region))

what are clinical manifestations of lumbar DDD?

• low back pain, saddle anesthesia

• reduced flexibility

• radiculopathy (sciatica (lower motor neuron region; hyporeflexia)

what describes radiculopathy?

compression/irritation of a nerve root that manifests with pain, paresthesia, weakness, and/or hyporeflexia along the distribution of the nerve root

why does radiculpathy occur?

due to disk herniation or spondylosis

how does radiculopathy mainfest?

with radicular pain, motor weakness (difficulty with fine motor), and loss of deep tendon reflexes in associated nerve root territory

how does cervical radiculopathy manifest?

headaches and shoulder pain with arm pain and weakness

how does lumbosacral radiculopathy present?

pain worse with lumbar flexion (sitting), sensory abnormalities (saddle anesthesia), motor weakness

what describes dermatomes?

an area of skin that receives sensory innervation from a specific spinal root

how are dermatomes helpful in diagnosing?

testing touch or sensory perception in these areas can be used to localize lesions of the spinal cord to a specific cord level or spinal nerve

lumbar radiculopathy most commonly affects what region?

L4/L5 and L5/S1 disc

in lumbar radiculopathy, what describes the pain?

either stabbing in nature or resembles an electric shock

in lumbar radiculopathy, when does pain increase?

with pressure (from coughing or sneezing and with flexion

in lumbar radiculopathy, when is pain decreaesd?

with minor changes in position (taking a short walk)

what is a diagnostic exam for lumbar radiculopathy?

straight leg raise test (since pain is increased with flexion)

the straight leg raise test assesses for what?

nerve root impingement in the lumbosacral region

what describes the straight leg raise test?

• with the patient in a supine position, the leg is lifted 30-70° with the knee in extension

• positive if the patient experiences pain radiating down the same leg

how can you diagnosis disc herniation?

via history, phyiscal exam, and imaging (MRI)

what is conservative management of DDD/disc herniation?

physiotherapy and analgesia + stay active

• severe pain = glucocorticoids

what is surgery for DDD/disc herniation?

diskectomy

• removal of the herniated portion of the IV disk

• indicated for patients with significant or progressive neurological deficits or persistent/progressive radiculopathy despite conservative management

what describes spinal stenosis?

narrowing of the central spinal canal, intervertebral foramen, lateral recess → progressive nerve root compression

spinal stenosis is most commonly caused by what?

degenerative joint disease and is seen primarily in middle-aged and elderly individuals

is lumbar or cervical spinal stenosis more common?

lumbar > > > cervical, thoracic is rare

what describes etiology of spinal stenosis?

• degenerative joint disease (DDD, facet joint arthropathy, spondylolisthesis, osteoarthritis)

• iatrogenic (following spinal surgery; ex: laminectomy)

• systemic disease (paget disease, tumor, ankylosing spondylitis)

• other (trauma, congentical malformations)

lumbar spinal stenosis’s pain is usually what?

gradual, subacute/chronic

• (if acute, its because of an exacerbation of underlying condition)

with lumbar spinal stenosis, radiculopathy usually occurs due to what?

underlying DDD

what presents as load-depending lower back pain that worsens with walking?

lumbar spinal stenosis

what is associated with lumbar spinal stenosis?

• neuropathic claudication (pain in the leg when walking)

• wide-based gait

• reduced lower extremity reflexes

neuropathic claudication presents how?

• bilateral radiation to glutes, thighs, or calves

• worse with lumbar extension

• relieved by lumbar flexion

lumbar spinal stenosis worsens with what?

lumbar extension

lumbar spinal stenosis is relieved with what?

lumbar flexion (shopping cart sign)

how does cervical spinal stenosis present?

• neck pain

• gait and balance disturbances

• increased urinary frequency or incontinence

• upper motor neuron signs (below the level of stenosis)

• lower motor neuron signs (at the level of stenosis)

• sensory abnormalities: pain, paresthesia, and/or anesthesia at or below the level of stenosis

• lhermitte sign* (radiating pain when neck is flexed)

with cervical spine stenosis, sensory areas supplied by what nerve may be affected?

trigeminal nerve

in regards to cervical spine stenosis, cervical pain can present as what?

pain in the jaw, temple, ear, periorbital region

in regards to cervical spine stenosis, patients can develop what?

cervicogenic headaches

what describes cervicogenic headaches?

• begins in cervical region, travels to the occipital region, radiates temporally, may extend periorbitally

• mimics a sinus headache

cervicogenic headaches, altered head and neck posture might be present due to what?

fatigue of head and neck muscles

• SCM, trapezius, masseter, temporalis

• produces muscle trigger points

how do you diagnose spinal stenosis?

clinical features and positive imaging are both required

• imaging: MRI spine without contrast or CT myelogram

• evidence of spinal stenosis: narrowing of the spinal canal, compression of the spinal cord/nerve root impingement

• imaging may also provide evidence for the underlying cause

how do you manage cervical spine stenosis?

surgery is preferred due to rise of severe neurological symptoms without treatment

how do you manage lumbar stenosis?

• conservative managment: NSAIDs, physiotherapy, image-guided epidural steriod injection

• surgery: decompression to relieve the spinal cord compression laminectomy/laminotomy with or without vertebral fusion