Miller-Spine Flashcards
Key aspects of the spine physical examination
![](https://s3.amazonaws.com/brainscape-prod/system/cm/306/362/848/a_image_thumb.png?1584711472)
Cervical Neurologic Examination
![](https://s3.amazonaws.com/brainscape-prod/system/cm/306/362/887/a_image_thumb.png?1584711569)
Findings in Cervical Compression
![](https://s3.amazonaws.com/brainscape-prod/system/cm/306/362/997/a_image_thumb.png?1584711633)
Findings in Lumbar Compression
![](https://s3.amazonaws.com/brainscape-prod/system/cm/306/363/004/a_image_thumb.png?1584711669)
Lower Extremity Neurologic Exam
![](https://s3.amazonaws.com/brainscape-prod/system/cm/306/363/019/a_image_thumb.png?1584711855)
Cervical Spine Anatomy
![](https://s3.amazonaws.com/brainscape-prod/system/cm/306/363/276/a_image_thumb.png?1584711969)
Review Cervical Myelopathy
Spinal cord compromise without reference to specific pathologic entity
□
Presenting symptoms can be subtle
•
Finger clumsiness, deterioration of handwriting, difficulty in fine motor control of hands, weakness of pinch
•
Ataxia with wide-based gait, leg heaviness, and inability to perform tandem walk
•
Urinary retention, urgency, or frequency
•
Lower extremity weakness (corticospinal tracts) can be associated with worse prognosis.
□
Natural history of cervical spondylotic myelopathy is characterized by one of three presentations:
•
Stepwise deterioration in symptomatology followed by a period of stability (most common, 65%–80%)
•
Slowly progressive decline (over months to years, 20%–25%)
•
Rapidly progressive decline (over days to weeks, 3%–5%)
□
Physical examination
•
Upper motor neuron findings in myelopathy
Myelopathy hand and the finger escape sign (small finger spontaneously abducts because of weak intrinsic muscles)
•
Hyperreflexia, Hoffmann sign, clonus, or Babinski sign
•
Inverted radial reflex (ipsilateral finger flexion when brachioradialis reflex being elicited)
•
Funicular pain—central burning and stinging with or without L’hermitte sign (radiating lightning-like sensations down the back with neck flexion)
•
Upper motor neuron findings not always present in all patients
•
Upper extremities may have radicular (lower motor neuron) signs along with evidence of distal myelopathy.
□
Treatment
•
Nonsurgical treatment—NSAIDs, cervical epidural injections, isometric exercises, traction, and occasionally temporary collar immobilization
•
Surgical indications—natural history of myelopathy is typically progressive; therefore surgical decompression is frequently indicated.
•
Procedures
•
Anterior procedures include ACDF versus ACCF or combination (hybrid). Anterior-based procedures are options for patients with either kyphotic or lordotic cervical sagittal alignment.
•
Posterior options include laminectomy and fusion versus laminoplasty. Posterior-based options are contraindicated in patients with fixed cervical kyphosis owing to the surgical inability to indirectly decompress the spinal cord.
•
Combined anterior and posterior procedures (circumferential surgery). Considered for patients requiring multilevel corpectomy resection with strut reconstructions (highly unstable spine).
Common measurements in C1-C2 disorders
![](https://s3.amazonaws.com/brainscape-prod/system/cm/306/363/944/a_image_thumb.png?1584712900)
Rheumatoid Cervical Spine
Overview
•
Less common owing to improvement and increased use of disease-modifying antirheumatic drugs (DMARDs)
•
Patients with rheumatoid arthritis (RA) should undergo flexion/extension radiography before elective surgery.
•
When spine is involved, cervical spine, more specifically occipitoatlantoaxial joint (O–C2), is site most commonly affected.
•
Atlantoaxial subluxation (AAS)—typically the first manifestation of cervical instability in rheumatoid patient
•
Atlantoaxial invagination (AAI)—typically occurs next, after AAS
•
Subaxial subluxation (SAS)—usually occurs after AAS and AAI
•
Occurs in up to 90% of patients with RA and is more common with long-standing disease and with multiple joint involvement
□
Presenting complaints
•
Axial neck pain
•
Stiffness
•
Occipital headaches
•
Due to erosion of the C1–2 joint, with subsequent compression of greater occipital branch of C2 nerve
•
Results more specifically in pain in posterior aspect of base of skull that is typically relieved with manual traction
•
Myelopathy, radiculopathy, or myeloradiculopathy, depending on neurologic structures at risk
□
Physical examination
•
Subtle signs of neurologic involvement should be sought.
•
Neurologic impairment (weakness, decreased sensation, hyperreflexia) in patients with RA usually occurs gradually and is often overlooked or attributed to other joint disease.
•
Neurologic impairment with RA has been classified by Ranawat (Table 8.6).
□
Imaging
•
Radiographic markers are assessed for indications of impending neural compression (Fig. 8.8).
•
Anterior atlantodens interval (AADI), frequently referred to simply as atlantodens interval (ADI)
•
Posterior ADI (PADI), sometimes also referred to as space available for the cord (SAC)
•
MRI
•
Cervicomedullary angle (CMA) (Fig. 8.9) is measured by drawing a line along anterior aspect of cervical spinal cord and the medulla.
•
Normal: 135–175 degrees
•
In patients with progressive superior migration of the odontoid, the CMA decreases owing to draping of the brainstem over the odontoid.
•
Reduced CMA has an increased association with respiratory dysfunction and sudden death.
□
Atlantoaxial subluxation (AAS)
•
Typically first stage of cervical spine involvement in the rheumatoid patient
•
Occurs in 50%–80% of patients with RA
•
Often the result of pannus formation at synovial joints between the dens and ring of C1, resulting in destruction of transverse ligament, dens, or both
•
Leads to instability between C1 and C2, with subsequent subluxation
•
Diagnosis
•
Anterior subluxation of C1 on C2 is the most common finding, but posterior and lateral subluxation can also occur.
•
Findings on examination may include limitation of motion, upper motor neuron signs, and weakness.
•
Plain radiographs that include patient-controlled flexion and extension views are evaluated to determine AADI as well as PADI.
•
Instability is suggested by AADI motion of more than 3.5 mm on flexion and extension views, although radiographic instability in RA is common and not necessarily an indication for surgery.
•
PADI less than 14 mm may be more sensitive than AADI measurement for spinal cord compression in patients with RA.
•
Surgical indications
•
Intractable pain
•
Progressive neurologic instability, cervical myelopathy
•
Can be due to mechanical instability
•
Direct compression by pannus of C2
•
Mechanical instability; evaluation of C1–2 motion/relationship
•
AADI greater than 9–10 mm
•
PADI less than 14 mm
•
PADI may be more sensitive for identifying patients at increased risk of neurologic injury
•
PADI less than 14 mm usually requires surgical treatment.
•
Surgery is less successful in patients with Ranawat grade IIIB neurologic impairment but should still be considered.
•
Treatment
•
Surgical fixation
•
Gallie fusion—mostly of historical significance
•
Brooks fusion—mostly of historical significance and rarely used alone
•
C1–2 transarticular screw fixation (Magerl)
•
Still used but less commonly since advent of C1–2 Harms construct (see later)
•
Requires preoperative CT to evaluate position of vertebral arteries
•
Requires reduction of C1–2 joint
•
Poses increased risk for vertebral artery and C2 nerve injury
•
C1 lateral mass—C2 pedicle/pars fixation (Harms construct)
•
Lower rate of vertebral artery and C2 nerve injury
•
Biomechanically strongest construct of C1–2 fixation techniques
•
Does not require reduction of C1–2 joint
•
Odontoidectomy
•
Should be reserved as a secondary procedure
•
Anterior cord compression by pannus often resolves after posterior spinal fusion.
□
AAI
•
Also known as cranial settling, basilar invagination, cranial invagination, and other names.
•
Second most common manifestation of RA in cervical spine
•
Occurs in 40% of patients with RA
•
Results in cranial migration of the dens from erosion and bone loss between the occiput and C1–2
•
Often seen in combination with fixed atlantoaxial subluxation
•
Measurements are shown in Fig. 8.8.
•
Landmarks may be difficult to identify.
•
Ranawat line is most reproducible.
•
Diagnosis
•
Progressive cranial migration of dens
•
Findings on examination may include limitation of motion, upper motor neuron signs, weakness, and, in severe cases, bulbar symptoms.
•
Surgical indications
•
Intractable pain
•
Progressive cranial migration or neurologic compromise may require operative intervention (occiput–C2 fusion).
•
Cervicomedullary angle less than 135 degrees (on MRI) suggests impending neurologic impairment.
•
Treatment
•
Occipitocervical fusion
•
Typically from occiput to C2
•
Gentle traction to help bring odontoid process out of foramen magnum
•
Transoral or retropharyngeal odontoid resection for persistent brainstem compression after occiput–C2 fusion.
□
SAS
•
Occurs in 20% of cases of RA
•
Seen in combination with upper cervical spine instability
•
Pathoanatomy
•
Pannus formation in uncovertebral joints (joints of Luschka) and facet joints. Subluxation may occur at multiple levels.
•
Radiographic markers of instability
•
Subaxial subluxation of greater than 4 mm or more than 20% of the body is indicative of cord compression.
•
A cervical height index (cervical body height/width) of less than 2.00 approaches 100% sensitivity and specificity in predicting neurologic compromise.
•
Surgical indications
•
Intractable pain
•
Progressive neurologic compromise, cervical myelopathy
•
Mechanical instability—subluxation greater than 4 mm
•
Procedure
•
Posterior spinal fusion with or without decompression
•
Fusion to the most distal unstable level.
•
Occiput and/or C1–2 joint included if AAI or AAS exists.
•
Anterior spinal fusion
May be required to restore sagittal alignment
May be necessary to increase likelihood of fusion on multilevel posterior spinal fusion
•
Surgery may not reverse significant neurologic deterioration, especially if a tight spinal canal is present, but can stabilize it.
What is the cervicomedulary angle and what does it mean
an angle less than 135 degrees on MRI suggests impending neurologic impairment
what is the cervical height index?
Diagram of the cervical nerve root orientation
Diagram of the lumbar nerve root orientation
![](https://s3.amazonaws.com/brainscape-prod/system/cm/306/365/753/a_image_thumb.png?1584969041)
Anterior soft tissue shadows normal numbers for trauma evaulation:
6mm C2
20mm C6
Review the ASIA classification
![](https://s3.amazonaws.com/brainscape-prod/system/cm/306/600/693/a_image_thumb.png?1585001015)
Review incomplete spinal cord injuries
Central cord syndrome
•
Most common incomplete spinal cord syndrome
•
Typical mechanism is hyperextension with preexisting canal stenosis.
•
Cord is compressed anteriorly by osteophytes and posteriorly by the infolded ligamentum flavum.
•
Cord is injured in the central gray matter, resulting in proportionately greater loss of motor function to upper extremities than to lower extremities.
•
The upper extremity is affected more than the lower extremity.
•
Variable sensory sparing
•
The prognosis is good for the recovery of ambulation, but the patient is less likely to recover upper extremity function.
•
Anterior cord syndrome (spinothalamic tract injury)
•
The second most common incomplete cord injury
•
No typical mechanism for injury
•
Direct compression to anterior spinal cord
•
Less commonly, vascular injury to anterior spinal artery, or spinal cord ischemia (e.g., anterior spinal artery, artery of Adamkiewicz)
•
Damage is primarily in the anterior two-thirds of the cord.
•
Loss of motor response, pain reception, and temperature reception below the level of injury
•
Patients demonstrate greater motor loss in the legs than the arms.
•
Preservation of posterior/dorsal column; vibration sensation, proprioception, and deep pressure sensation intact
•
The prognosis for motor recovery is poor.
•
Brown-Séquard syndrome (spinal cord hemisection)
•
Typical cause is penetrating trauma.
•
Ipsilateral loss of motor and loss of position/proprioception function on the side of injury
•
Contralateral loss of pain and temperature to the side of injury (usually one to two levels below the insult)
•
Best prognosis for recovery of ability to walk (90%)
•
Posterior cord syndrome
•
Very rare; least common incomplete spinal cord pattern
•
Injury to posterior/dorsal column—loss of proprioception, vibrator sensation, and deep pressure sensation
•
Preservation of anterior column; motor response, pain reception, and temperature reception intact
![](https://s3.amazonaws.com/brainscape-prod/system/cm/306/600/697/a_image_thumb.png?1585001148)