Lumbar facet joint IMAGING

Lumbar facet joint effusion on
MRI: a sign of instability in
degenerative
spondylolysthesis?
F Lattig*, D Grob~, F Kleinstück~,
T Fekete~, F Porchet~, AF Mannion~
* Department of Orthopaedics, , University Medical Center, Göttingen, G
Germany
~ Spine Center, Schulthess Klinik, Zürich, Z
Switzerland
Contact address: : Friederike Lattig, MD
Consultant Spinal Surgery
Robert-Koch-Strasse 40, 37075 Göttingen, G
Germany
e-mail: friederike.lattig@med.uni-goettingen.de

Introduction
Facet joint effusion is often observed
on supine MRI of patients with
degenerative spondylolisthesis (DS),
but not in all.
This sign was investigated as a
possible indicator for instability in DS
and rotational translation (RT).

Questions
Is the degree of distension of facet joints
seen on MRI correlated with the degree of
segmental mobility when comparing
standing and lying positions?
Is unilateral facet joint effusion, or a
notable difference in the degree of
effusion between right and left joints,
associated with rotational translation?

Patients
160 patients that had undergone
surgery for DS were identified
retrospectively from our spine surgery
database (collected
in connection with
Spine Tango)
All patients had preoperative upright
ap and lateral x-rays and supine MRI
of the lumbar spine

Methods
Imaging studies were assessed for
the following parameters:
- percent of slippage
- absolute value of facet joint effusion
- facet angles
- degree of facet degeneration
- degree of spinal canal narrowing
- disc height
- presence of rotational translation
- presence of facet cysts

Results I
160 patients (119 female, , 41 male) fulfilled the study
admission criteria
Mean age 68.8y (range(
38.8 to 89.3y)
Patients were divided into two groups based on the
percentage slip difference between upright and supine
positions: ≤ 3% (N=52) or > 3% (N=108)
All 108 patients with a slip difference >3% had facet
effusion; 40/52 (77%) with a slip difference ≤3% had no
facet effusion
Percentage slip difference
between upright and
supine positions ≤3%
Percentage slip difference
>3%
Facet joint
effusion positive
N = 12
N = 108
Facet joint
effusion negative
N =40
N = 0

Results II
As the table below shows, the group with a % slip difference between
MRI and X-ray of more than 3% showed a significantly higher mean joint
effusion (p=0.0001), whereas the mean disc height and the percentage
slip in X-ray were similar in the two groups.
Difference % slip MRI-
X-ray ≤3% (N=52)
Difference % slip
MRI-X-ray >3% (N=108)
p value
Age (yrs) (mean (SD))
72.0 (7.4)
68.7 (9.9)
0.04
Gender m:f (number, %)
15:37 (29%:71%)
26:82 (24%:76%)
0.52
Difference % slip MRI-X-ray (mean (SD))
1.6 (1.2)
10.4 (4.6)

Results III
In the 108 patients with a percentage slip difference >3% between MRI
and X-ray, there was a significant correlation between facet effusion
(mm) and percentage difference in slippage between MRI and X-ray (%)
(r= 0.63, p < 0.05).
35.0
30.0
y = 3.4945x + 2.9826
R 2 = 0.4108
% difference MRI-x-ray
25.0
20.0
15.0
10.0
5.0
0.0
0.0 1.0 2.0 3.0 4.0 5.0 6.0
mm effusion

Results IV
As shown in the graph below, in the group of 108 patients
with more than 3% difference in slippage, patients with
rotatory translation (n=52, dark grey) showed greater facet
joint effusion differences between right and left sides (in mm)
compared with those without rotatory translation (n=56, light
grey) (p

Conclusion
Facet joint effusion is clearly correlated with
spontaneous reduction of the extent of
slippage in the supine position compared to
the upright position.
The greater the difference in right and left
facet effusion, the higher the likelihood of
having RT instability.
Hence, facet joint effusion could be a sign of
segmental instability in DS and RT, and
might help in decision-making, when
considering whether to perform a fusion in
addition to decompression.