A presentation at KOACON 2016- e poster

1. TECHNIQUE OF PERCUTANEOUS
ILIOSACRAL SCREW FIXATION OF
SACROILIAC DISRUPTIONS WITH THE
PATIENT IN SUPINE POSITION
Dr. Libin Thomas Manathara
KOACON Regn. no. 50083

2. Dr. Libin Thomas Manathara,
KOACON 2016 Regn. No. 50083
2
CASE PRESENTATION
• 39yr old female nurse involved
in a road traffic accident
complaining of severe lower
back pain and inability to move
the right hip
• Initial radiogrpahs revealed a
right sacroiliac joint disruption
and right inferior pubic ramus
fracture. A CT taken confirmed
the same. A 3D reconstruction
image is displayed
• After pre op evaluation she
was planned for a right
percutaneous sacroiliac screw
fixation using a modification of
the Routt et al technique with
patient in supine position

3. Dr. Libin Thomas Manathara,
KOACON 2016 Regn. No. 50083
3
• It is important to note that the normal sacral
ala has an inclined anterosuperior surface,
the sacral alar slope, that extends from
proximal-posterior to distal-anterior
• It is because of this slope that we use 3
different AP views to confirm our guide wire
is in the right place
• Anterior to the sacral ala in this region run
the L5 nerve root and the iliac vessels
• The cortex of the alar slope forms the
anterior boundary of the “ safe zone ” for
passage of iliosacral screws into the body of
S1
• The posterior boundary of the safe zone is
formed by the foramen of the S1 nerve root
• The sacral alar slope can be estimated on a
true lateral fluoroscopic view of the sacrum
by identifying the iliac cortical density (ICD),
which demarcates the anterior cortical
thickening of the iliac portion of the
sacroiliac joint
THE ANATOMY OF THE
SACRAL ALA

4. Dr. Libin Thomas Manathara,
KOACON 2016 Regn. No. 50083
4
With the patient in supine position, the landmarks iliac crest and greater trochanter were marked and a
C- arm was used to identify the entry port. The entry port would be created with a vertical arm and an
intersecting horizontal arm. A K wire was used to aid us in this process. Here you can see the K wire
being placed over the hip to mark the vertical arm

5. Dr. Libin Thomas Manathara,
KOACON 2016 Regn. No. 50083
5
Marking the vertical arm of the entry point
• The C arm images showing the K wire in the right
place in a true AP and a 40 degree caudal view are
displayed
• Our marking on the patient is also shown, both lines
would intersect at a point on the lateral aspect of
pelvis marking the vertical arm of the entry point

6. Dr. Libin Thomas Manathara,
KOACON 2016 Regn. No. 50083
6
Varying views to identify the
vertical arm of the entry point
• The anteroposterior
view, 40 degrees
cephalad and 40
degrees caudal
views were used to
ascertain that the
vertical arm remains
in the sacral
promontory
• This is due to the
sacral alar slope as
described earlier

7. Dr. Libin Thomas Manathara,
KOACON 2016 Regn. No. 50083
7
Marking the horizontal arm of the entry point
• This is done using a K wire as shown
previously, the mark is kept in the safe
zone, as described earlier, just behind
the iliac cortical density (ICD) and in
front of the foramina of the S1 nerve
root

8. Dr. Libin Thomas Manathara,
KOACON 2016 Regn. No. 50083
8
The guide wire is advanced and its position too is confirmed in the manner
used previously. A 6.5 by 110mm cannulated partially threaded cancellous
screw with a washer was also advanced after drilling over the guide wire and
taking appropriate measurements

9. Dr. Libin Thomas Manathara,
KOACON 2016 Regn. No. 50083
9
Intra operative C arm images of the screw in place
• The image on the
left shows the
screw in the safe
zone of the sacral
ala just behind the
iliac cortical
density (ICD)
• Anteroposterior
view is also seen,
the washer is also
clearly visible

10. Dr. Libin Thomas Manathara,
KOACON 2016 Regn. No. 50083
10
Immediate post operative x ray shows a satisfactory
placement of the screw in anteroposterior view

11. Dr. Libin Thomas Manathara,
KOACON 2016 Regn. No. 50083
11
35th post operative day follow up
• The patient was seen on
the 35th post op day and
she has a significant
decrease in pain
• The early follow up X rays
show good reduction with
proper screw placement
• The patient was allowed
weight bearing 3 months
after the date of surgery