Reciprocal Changes Assessment in
Adjacent Mobile Level following
Monosegmentar Interbody Fusion
Enrique Vargas, Rodrigo Amaral, Luis
Marchi, Leonardo Oliveira, Fernanda Fortti,
Etevaldo Coutinho, Rubens Jensen
Instituto de Patologia de Coluna (IPC) - São Paulo - Brazil
2015
DISCLOSURE
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•
•
•
•
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Enrique Vargas; nothing to disclose
Rodrigo Amaral ; consultant (NuVasive)
Luis Marchi ; nothing to disclose
Leonardo Oliveira ; nothing to disclose
Fernanda Fortti ; nothing to disclose
Etevaldo Coutinho ; nothing to disclose
Rubens Jensen; consultant (NuVasive)
IPC - grant/research support (MDT implantes)
Background
• 60% of the overall lumbar lordosis is located in L4L5 and
L5S1
• The main cause of sagittal imbalance in degenerative
lumbar spine is the loss of lumbar lordosis
• With DDD, index lordosis is extremelly diminished and
can lead to segmental and global imbalance
• The pelvis may also be retroversed, resulting in a
decreased sacral slope to compensate for the sagittal
imbalance
• Postoperative improvement in L5 incidence and slip angle
has been correlated with better outcomes.
J Neurosurg Spine 7:387–392, 2007
Objective
The purpose of this paper is to analyze the
contribution of a standalone L5S1 interbody
procedure toward the treatment of degenerative
disc disease and study resultant local sagittal
parameters
Hypothesis
In DDD L5S1
↓ L5S1 lordosis; ↑ L4L5 lordoses
After ALIF in L5S1
↑ L5S1lordosis; ↓ L4L5 lordoses
Inclusion/ Exclusion
Inclusion
stenosis, DDD, instability and/or
low-grade spondylolisthesis
diagnosis
stand-alone L5S1 ALIF with selflocking lordotic interbody cage
Exclusion
previous lumbar fusion
Radiological measures
2 independent evaluators
• X-rays orthostatic neutral
– Preop
– 3 months
 Lumbar lordosis
 L4L5 lordosis
 L5S1 lordosis
 Sacral slope
 L5 takeoff
A
B
Study cohort
• 35 cases
• 25 F /10 M
• 47±15 y/o
Radiological results
Tabela 1. Reciprocal changes following L5S1 ALIF
Preop
3 months Pre x 3m; p a Pre x Pre; p b
L5S1 level
19° ± 8°
28° ± 5°
<0.001*
0.091
L4L5 level
17° ± 6°
14° ± 5°
<0.001*
L5S1 disc
10° ± 7°
18° ± 4°
<0.001*
0.024*
L4L5 disc
12° ± 4°
9° ± 3°
<0.001*
Lumbar Lordosis
52° ± 10°
53° ± 12°
0.461
L5 takeoff
17° ± 9°
13° ± 9°
0.007*
Sacral Slope
37° ± 9°
40° ± 9°
0.002*
-
3m x 3m; p c
<0.001*
<0.001*
-
Mean ± Standard Deviation. * statistically significant. (a) Preop versus 3 months. (b) Preop versus Prep. (c)3 months versus 3 months.
Resultados Radiológicos
L5S1 lordosis gain; L4L5 lordosis loss
L4L5 x L5S1 lordosis change
2,0
0,0
-10
-5
0
-2,0
-4,0
-6,0
-8,0
-10,0
-12,0
5
10
15
20
25
Exemples
#1
#2
Exemples
#3
#4
Conclusion
Lumbar lordosis is not affected by L5S1 ALIF
Reduction of compensatory lordosis of the adjacent
mobile level after ALIF with disc height and lordosis
restoration of index level.
Maintenance of physiological sagittal
parameters in levels adjacent to fusion
could reflect in lower rates of ALD.