Spine Flashcards
What is the physiologic range of motion of the cervical spine?
Flexion
Extension
Lateral Bending
Bilateral Rotation
90 deg flexion
70 deg extension
45 deg lateral
90 bilateral rotation
What are the methods to measure cervical lordosis?
Modified Cobb (Endplate of C2 and inferior endplate of C7)
Jackson physiologic stress
Harrison posterior tangent
Ishihara index
A cSVA greater than what is considered abnormal in the cervical spine?
50 mm
(distance from a vertical plumb line at C2 to the superior posterior corner of C7)
The angle formed from the inersection of a vertical line and a line between the chin and brown is what?
CBVA (normal value is -10 to 20 deg)
A T1 slope minus cervical lordosis of what is considered normal?
20 degree
What is the name for a chin to chest deformity?
Dropped head syndrome
What is the definition of proximal junctional kyphosis?
Increase in more than 10 degrees in the upper instrumented vertebra
An ACDF at a single level can provide what maximum degrees of additional lordosis?
3-5 degrees
A Smith Petersen Osteotomy may resuly in appoximately what amount of lordosis?
10 degrees
A patient is scheduled for anterior based spine surgery but has a history of a previous anterior cervical spine surgery, what should be assessed?
Vocal cord function by way of layngoscopy
What are the complication rates and revision rates for the surgical treatment of cervical spine deformity?
20% for complications and 12% for revision
What are the risk factors for distal junctional kyphosis after cervical deformity correction?
Severe preoperative cervical deformity (cSVA), T1S-cervical lordosis, and thoracic kyphosis
Degenerative spondylolisthesis of cervical spine is found where?
C3-C4
What is the most common adverse postoperative complication of laminoplasty for multilevel cervical spondylotic myelopathy?
Loss of cervical range of motion
What structure is most at risk with anterior penetration of C1 lateral mass screws?
Internal carotid artery
Isthmic spondylolisthesis most often occurs at what level?
L5/S1
5% of population, especially innuits and young males in repetitive hyperextension activities
What is defined as 100% translation of one vertebra over the next caudal vertebra?
Spondyloptosis
Why are isthmic slips more prone to progression at L4/5 instead of L5/S1?
Because the iliolumbar ligament adds stability to L5/S1
What spinal measurement parameter means increased loaging on the L5 pars articularis?
High pelvic incidence and high sacral slope
True or False: Spondylolisthesis is believed to be related to an autosomal dominant genetic predisposition with incomplete penetrance
True
When is pars repair indicated in isthmic spondylosis?
Persistent symptoms, minimal degenerative disk disease, no slippage, no discogenic component to pain
For adult isthmic spondylosis, evidence supports higher fusion rates with use of anterior column support for what grades?
Grades 3-4, NOT grades 1-2
What cervical level is most common for degenerative spondylolisthesis?
C3-C4
What percentage of anterior iliac crest graft patients have chronic hip pain?
0.25%
What are the risk factors for airway compromise after anterior cervical surgery?
Surgery greater than 5 hours
More than 4 levels
Autologous bone graft, bone marrow aspirate, are examples of what kind of bone graft?
Osteogenic (Have live cells)
True or False: Biomechanical studies have demonstrated compressive and tensile strength similar to that of frozen allograft but reduced torsional/bending strength compared with fresh or fresh-frozen bone because of the drying process
True
What BMP was FDA approved in 2002 for use in ALIFs?
BMP-2 for grade-1 spondylolisthesis and degenerative disease
(Also approved for tibial nonunion in 2004)
Bioelectric potential is electro-what in areas of compression?
Eletronegative
What Type of Adult Scoliosis is attributed to primary degenerative changes?
Type 1
(Type 2 is progression of AIS and Type 3 is secondary to something else)
What defines osteoporosis?
T-score less than –2.5 or an osteoporotic fracture
Sagittal realignment targets have been suggested, including a SVA less than (1) mm, pelvic tilt less than (2)°, lumbar lordosis = pelvic incidence ± (3)°, and T1 SPI less than (5)
SVA < 50 mm
PT < 20
LL - PI = 9
Less than 0
What are the levels we want for deformity surgery optimization:
BMI
Albumin
A1C
Hemoglobin
Vitamin D (25OHD)
DEXA
Morphine Equivalents
BMI < 35
Albumin > 3.5 g/dL
A1C < 7%
12 for men and 13 for women
Vitamin D > 30 ng/mL (if low, initiate 50,000 weekly)
DEXA > -2.5
Morphine <10 mg/d
In spine surgery, what does cross-links increase?
rotational stability and strength
With correction of spinal deformity, what level has the greatest incidence of psuedoarthrosis?
L5-S1
Most major and minor complications of ASD surgery occur when?
Less than 3 months postoperatively or 2 years (PJK and implant failure)
Increased risk with obesity, ASA, 3 column osteotomy, correction of kyphosis
Complication rate at 55%
By age 65, what percentage of men and women will have degenerative spine changes?
95% of men and 70% of women
Cervical disc disease most commonly involves what level?
C5-C6
On cervical spine XRs, what is the normal distance expected from the back of the posterior body to the spinolaminar line?
14 mm or more
What composes pavlov’s ratio for the cervical spine?
canal / vertebral body width
The facet is innervated by what?
Medial branch and dorsal primary rami of the sinuvertebral nerve
What are the waddell signs?
Tenderness to light touch
Pain in nonanatomic
Loss of findings during distraction
Overreaction
Pain on axial head loading
What are two significant risk factors for airway complications after an ACDF?
OR Time Greater than 5 hours
Exposure of 4 or more vertebral bodies
For SSEP, what are considered significant changes?
50% amplitude
10% latency
What disc pathology is a contraindication to posterior keyhole laminoforaminotomy?
Central disc herniation
What is the first stage of cervical spine involvement in RA patients?
Atlas Axis subluxation (50-80%)
-Pannus formation at synovial joints
Instability at C1/C2 is suggested by ADI motion of more than what in flexion and extension?
3.5 mm
What is a hypothetical line drawn between the hard palate and the most caudal point of the occipital curve. When the odontoid tip is > 4.5 mm above this line, then basilar invagination is considered
Mcgregors line
What is the Magerl fixation?
C1-C2 transarticular screw fixation
Requires reduction of C1/C2 joint
What is the harms construct?
C1 lateral mass screws and C2 pedicle/pars fixation
-Biomechanically strongest construct of C1-C2
-Does not require reduction of C1/C2 joint
Cervicomedullary angle of what suggests impending neurologic impairment?
Less than 135 degrees
OPLL is commonly seen in what patient population?
Asian and Men
An anterior cervical plate for a ACDF move center of rotation where?
Anteriorly
Name of the 6 types of spondylolisthesis
Dysplastic
Isthmic
Degenerative
Iatrogenic
Pathologic
Traumatic
What is the general indication for repair of a pars defect?
Younger patients with slippage less than 10% and a pars defect that is at L4 or above
According to the SPORT trial, how did operative treatment of degenerative spondylolisthesis compare to conservative treatment?
At 4 years, operative was better for primary outcome measures (SF-36, ODI)
What are the cephalad and medial degrees for a C1 lateral mass screw?
22 degrees cephalad, 10 degrees medial
What percentage of patients with isthmic spondylosis will progress to spondylolisthesis?
15%
In cauda equina, what symptom if present is least likely to improve?
Bladder dysfunction
What is the most common complication after a PSO?
Pseudoarthrosis (29%)
What direction of thoracic curve should plan for an MRI?
Left curving thoracic curve
Degrees of correction with ponte/smith peterson?
5-10 degrees
What uses low volume, high pressure, low viscosity for vertebral body fractures?
Vertebroplasty (does not allow correction) “vertebra focuses on vertebra”
Name three tumors of spine posterior elements:
ABC, osteoid osteome, osteoblastoma
Jailhouse striations on xray of the spine indicate what?
Hemangioma
What is the most common symptom with cauda equina?
Back and leg pain
The MRI finding most consistent with a complete spinal cord injury is what found in the cord?
Hematoma
What is the most important risk factor for complications for deformity surgery?
Older age
