Clinical instability of the lumbar spine following injury can be diagnosed using a checklist reported by White and Panjabi.
Parameters:
(1) status of anterior elements
(2) status of posterior elements
(3) radiographic criteria on flexion/extension or resting X-rays of the spine
(4) status of cauda equina
(5) anticipated loading
Parameter |
Finding |
Points |
anterior elements |
destroyed or unable to function |
2 |
|
not destroyed and able to function |
0 |
posterior elements |
destroyed or unable to function |
2 |
|
not destroyed and able to function |
0 |
cauda equina |
damage present |
3 |
|
damage absent |
0 |
anticipated loading |
dangerous |
1 |
|
not dangerous |
0 |
X-ray Type |
Measure |
Finding |
Points |
flexion/extension |
sagittal plane translation |
> 4.5 mm OR > 15% |
2 |
|
|
<= 4.5 mm AND <= 15% |
0 |
|
sagittal plane rotation |
L1-L2 > 15° L2-L3 > 15° L3-L4 > 15° L4-L5 > 20° L5-S1 > 25° |
2 |
|
|
L1-L2 <= 15° L2-L3 <= 15° L3-L4 <= 15° L4-L5 <= 20° L5-S1 <= 25° |
0 |
resting |
sagittal plane displacement |
> 4.5 mm OR > 15% |
2 |
|
|
<= 4.5 mm AND <= 15% |
0 |
|
relative sagittal plane angulation |
> 22° |
2 |
|
|
<= 22° |
0 |
where:
• Either the flexion/extension or resting X-rays finding are used, probably whichever is greater.
• The maximum points for radiographic criteria is 4.
Measurement of vertebral translation or displacement in a lateral X-ray view:
(1) This is shown in Figure 5-61 on page 354.
(2) A straight line is taken along the superior surface of the vertebra in question.
(3) A vertical line is drawn perpendicular to the straight line that goes through the posterior inferior aspect of the vertebra immediately above.
(4) distance B = width through the vertebral body immediately above in its vertical midpoint
(5) distance A = measurement from the point of intersection between the straight and vertical line along the straight line to the posterior superior aspect of the vertebra in question
(6) Abnormal if A > 4.5 mm OR A/B > 0.15
Measurement of sagittal plane rotation in a lateral X-ray view:
(1) This is shown in Figure 5-63 on page 355.
(2) Angle A = angle formed anteriorly by the meeting of a straight line through the superior aspect of the body of the first vertebra and a straight line through the superior aspect of the body of the second vertebra when the spine is flexed anteriorly.
(3) Angle B = angle formed posteriorly by the meeting of a straight line through the superior aspect of the body of the first vertebra and a straight line through the superior aspect of the body of the second vertebra when the spine is extended posteriorly.
(4) By convention lordosis is indicated by a negative value and kyphosis is indicated by a positive value. In the example given angle B is a negative number.
(5) sagittal plane rotation = A - B
Measurement of relative sagittal plane angulation in a lateral X-ray view:
(1) This is shown in Figure 5-62 on page 355.
(2) Angle B1 = angle formed posteriorly by the meeting of a straight line through the superior aspect of the body of the vertebra 2 above the spinal unit in question (L2 for L4-L5 unit) and a straight line through the superior aspect of the body of the vertebra 1 above the unit (L3 for L4-L5).
(3) Angle B2 = angle formed anteriorly by the meeting of a straight line through the superior aspect of the body of the vertebra 1 above the spinal unit in question (L3 for L4-L5 unit) and a straight line through the superior aspect of the first vertebral body of the unit (L4 for L4-L5).
(4) Angle B3 = angle formed posteriorly by the meeting of a straight line through the superior aspect of the first vertebral body of the unit (L4 for L4-L5) and a straight line through the superior aspect of the body of the second vertebral of the unit (L5 for L4-L5).
(5) By convention lordosis is indicated by a negative value and kyphosis is indicated by a positive value. In the example given angles B1 and B3 were negative values.
(6) If either B2 – B1 or B2 – B3 is > 22°, then the angulation is abnormal.
score =
= SUM(points for all the parameters)
Interpretation:
• minimum score: 0
• maximum score: 12
• A score >= 5 indicates that the lumbar spine is clinically unstable.
Specialty: Surgery, orthopedic, Emergency Medicine, Critical Care, Surgery, general
ICD-10: ,