Spondylolisthesis Flashcards
1
Q
What is a Spondylolisthesis?
A
Generic term to indicate slippage of a vertebra
2
Q
What do you use in a suspected Spondylolisthesis to compare the involved segment to the level below it?
A
Posterior Vertebral Body Line (George’s Line)
3
Q
What are the 4 things that should be described for every spondylolisthesis?
A
- Level
- Direction
- Degree
- Due to
4
Q
Spondylolisthesis: Report the ___ rather than the ___
A
level; motion segment
5
Q
Describe an Anterolisthesis
A
Anterior slippage
6
Q
Describe a Retrolisthesis
A
Posterior slippage
7
Q
Describe a Laterolisthesis
A
Lateral slippage to the right or left
8
Q
What does the degree of a Spondylolisthesis reprsent?
A
Helps quantify the amount of slippage in millimeters or centimeters
9
Q
What type of Spondylolisthesis has a Grading scale?
A
Anterolisthesis (Myerding classification)
10
Q
What types of Spondylolisthesis cannot be applied to the Myerding classification?
A
Retrolisthesis
Laterolisthesis
11
Q
What % is Myerding classification Grade 1?
A
0-25% anterior translation
12
Q
What % is Myerding classification Grade 2?
A
25-50% anterior translation
13
Q
What % is Myerding classification Grade 3?
A
50-75% anterior translation
14
Q
What % is Myerding classification Grade 4?
A
75-100% anterior translation
15
Q
What % is Myerding classification Grade 5?
A
> 100% anterior translation
16
Q
What should you remember when looking at the etiology of Spondylolisthesis?
A
Always look at the posterior elements
17
Q
What are the six components of Wiltse classification?
A
- Dysplastic
- Isthmic (Pars interarticularis involved)
- Degenerative
- Traumatic (Region other than pars involved)
- Pathologic
- Iatrogenic
18
Q
What are the two most common components of Wiltse classification?
A
- Isthmic
- Degenerative
19
Q
Describe a Dysplastic Spondylolisthesis
A
Congenital or developmental anomaly of the posterior arch
20
Q
Dysplastic Spondylolisthesis: More common in cervical or lumbar spine?
A
Cervical spine
21
Q
Dysplastic Spondylolisthesis: What might the cervical region show?
A
Absent articular pillars
22
Q
Dysplastic Spondylolisthesis: What will the lumbar region show?
A
Elongated or Malformed posterior element
23
Q
Dysplastic Spondylolisthesis: Common or Uncommon etiology?
A
Uncommon etiology
24
Q
Describe an Isthmic Spondylolisthesis
A
Involves the pars interarticularis in the lumbar spine
25
What is the MC location for an an Isthmic Spondylolisthesis?
LS (90%)
- L4 (4%)
- L1, L2, L3 (3%)
26
Describe an Isthmic Type 2A Spondylolisthesis
Fatigue fracture of the pars AKA Spondylolytic
- common in gymnast and mechanic
27
What is the MC type of Isthmic Spondylolisthesis?
Type 2A Spondylolytic
28
Describe an Isthmic Type 2B Spondylolisthesis
Elongation but intact pars
- microtrauma
- remodeling
29
Describe an Isthmic Type 2C Spondylolisthesis
Acute traumatic pars fracture
- MVA
- Hit in sports
30
What is the most common spondylolisthesis in people under the age of 50?
Isthmic 2A Spondylolytic
31
What causes a Isthmic 2A Spondylolisthesis?
Due to a fatigue fracture of the pars that heals non-union
- Not a congenital anomaly
- Can have spondylolysis without spondylolisthesis
32
How do you properly describe an Isthmic 2A Spondylolisthesis?
Pars defect is used over pars fracture (fracture implies acute injury)
33
Why is there a difference in incident rates of Isthmic 2A Spondylolisthesis between certain populations?
Differences in incidence believed to be due to the thickness of the pars interarticularis
34
Which patient histories should make you search for a pars defect (3)?
1. Adolescent patient (10-15 YOA)
2. Repetitive hyperextension loading
3. Fatigue fracture of the pars interarticularis
- Continuation of activity
- Resulting in non-union healing
35
Which populations are at an increased risk for Isthmic 2A Spondylolisthesis?
- Gymnasts
- High divers
- Cheerleaders
- Weightlifters
- Pole-vaulters
36
What imaging should you order is an active pars fracture is suspected?
1. Radiograph
2. MRI
37
What radiographic series should you order if an active pars fracture is suspected?
-AP, Lateral, and Oblique views
- For L5, Ferguson (tilt-up) view
38
What kind of MRI should you order if an active pars fracture is suspected?
MRI w/o contrast to assess for bone marrow edema in the area of the defect
- can signify acute fatigue fracture or instability
39
How do you treat a patient with an active pars defect?
- Get the patients off activity
- Boston brace (typically done via an orthopedist)
40
What is the radiographic approach for an Isthmic 2A Spondylolisthesis?
1. Check the AP and lateral first
- if you see the defects then no reason to do additional views
2. If still unsure, at L5 use Ferguson view
- other levels and AP should show it however the obliques may be more rewarding
41
What part of the Scotty dog is the pars interarticularis?
Pars is the neck of the dog
42
How will patients present with an Isthmic 2A Spondylolisthesis?
The active 2A will present with back pain
43
What should you do if you can diagnose an active Isthmic 2A pars defect?
- Remove from activity
- Utilize a brace to allow fatigue fracture to heal (may take ~6-8 weeks to heal)
44
What happens once an Isthmic 2A Spondylolisthesis heals non-union?
Majority are asymptomatic
45
Isthmic 2A Spondylolisthesis: Strong or Poor correlation between severity of slippage and symptoms?
Poor correlation
46
What shouldn't patients with an asymptomatic spondylolisthesis be prevented from doing?
Participating in sports or other physical activity
47
What are the physical exam findings of an Isthmic Type 2A Spondylolisthesis (3)?
1. Accentuated lordosis
2. Stork test (if active)
3. Spinous process with palpable defect
- Isthmic: SP of above segment moves anteriorly
- Degenerative: SP of affected segment moves anteriorly
48
What does an Isthmic 2A type Spondylolisthesis look like in adults?
1. Major concern for instability
2. Believed to an incidental finding
3. Would result in widening or opening of the spinal canal
- may narrow the IVF over a long period of time
49
What factors increase the risk of progression for an Isthmic 2A Type Spondylolisthesis?
- 2-3% will show progression
- Occurs between 5-15 YOA
- Most likely within the first 2 years after fracture
- <18 YOA
50
What factors reduce the likelihood of progression of Isthmic 2A Type Spondylolisthesis?
- Male
- Low grade slippage
- Buttressing (laying down more bone)
- Older than 18 YOAs
51
What are common indicators of progression or instability in Isthmic 2A Type Spondylolisthesis?
- Poor response to conservative management
- Serial progression documented from prior imaging
- Higher grade slippage is more likely (Grade 3+)
- Rounding of the sacral base (doming)
- Trapezoidal L5 vertebral body shape (posterior appears shorter than the anterior height)
52
What is an Isthmic 2B Type Spondylolisthesis?
A cycle of fatigue fracture, healing, then another fatigue fracture
53
What does an Isthmic 2B Type Spondylolisthesis lead to?
Elongation/Remodeling
54
Isthmic 2C: Rare or Common?
Rare
55
What is the MOI of an Isthmic 2C Type Spondylolisthesis?
Secondary to acute hyperextension
- Being clipped in football
- Often see other injuries (compression fractures)
56
Isthmic 2C Type Spondylolisthesis: What can be hard to determine on a radiograph?
Chronicity
57
Isthmic 2C Type Spondylolisthesis: What is required for characterization?
MR or CT imaging
58
True or False: Unilateral Spondylolysis is less common than a bilateral.
True
59
What are some characteristics of a Unilateral Spondylolysis
- Frequently overlooked on imaging
- No spondylolisthesis would be visualized
60
What might a Unilateral spondylolysis progress to?
May heal or progress into a bilateral defect
61
What do we see radiographically with a Unilateral Spondylolysis?
Wilkinson Syndrome --> Dense unilateral sclerotic pedicle
62
What is a DDX of a Unilateral Spondylolysis?
Osteoid Osteoma
63
What is the most common type of Spondylolisthesis in patients older than 50 YOA?
Degenerative
64
What does the slippage seen in Degenerative Spondylolisthesis result from?
Facet or disc degeneration
- facet orientation changes with advanced facet degeneration
65
Degenerative Spondylolisthesis: Neural arch intact or broken?
Neural arch will be intact
66
What is the most common level for a Degenerative Spondylolisthesis?
MC level is L4
67
What is a Degenerative Spondylolisthesis associated with?
- Central canal stenosis
- Neurogenic claudication
68
True or False: Degenerative Spondylolisthesis typically won't be greater than a Grade 1
True
69
What is a Traumatic Spondylolisthesis?
Acute fracture of the posterior arch not involving the pars interarticularis
70
Define a Hangman fracture
Fracture of the C2 pedicle region
71
What do we see radiographically with a Traumatic Spondylolisthesis?
Facet dislocation (uni or bilateral)
72
What are 4 diseases that result in weakening of the pars interarticularis, increasing its susceptibility to fracture?
1. Osteoporosis
2. Metastasis
3. Paget
4. Osteopetrosis
73
True or False: Iatrogenic Spondylolisthesis is apart of original Wiltse Classificaiton.
False
74
Where is an Iatrogenic Spondylolisthesis commonly seen?
Adjacent segments to a surgical fusion
75
What is your first step when presented with an Iatrogenic Spondylolisthesis?
Obtain flexion and extension views
76
How do you test the instability of a Spondylolisthesis?
Functional radiography
Compression-traction
Flexion-Extension
77
What is the Yochum value for lumbar instability?
4mm of translation
- Excessive angular motion (>11 degrees)
78
How do you manage a stable (inactive) spondylolisthesis?
- Chiropractic treatment
- Biomechanical evaluation of the pelvis and lower extremity
79
How do you manage an unstable (active) spondylolisthesis?
- Boston antilordotic brace (acute)
- Surgical arthrodesis (chronic)
80
What are 3 etiologies of a Cervical Spondylolisthesis?
- Congenital
- Traumatic (Facet dislocations, Hangman Fx.)
- Degenerative
81
What level is a Cervical (Congenital/dysplastic) Spondylolisthesis most common at?
C6
82
What radiographic features do we see with a Cervical (Congenital/dysplastic) Spondylolisthesis?
- Anterolisthesis usually seen
- Spina bifida occulta
- Hypoplastic pedicles and articular processes
83
What do we see radiographically with a Cervical (Degenerative) Spondylolisthesis?
- Can see anterolisthesis or retrolisthesis
- Usually involves the mid-cervical region
