Synthes Small Stature USS User manual

Instruments and implants
approved by the AO Foundation
Small Stature USS. Dual-opening, low
profile hooks and screws for spinal
fixation.
Technique Guide

Introduction
Surgical Technique
Product Information
Table of Contents
Small Stature USS 2
Indications 3
Preoperative Planning 4
Place Hook 5
Prepare Pedicle 7
Insert Screw 9
Contour Rod 10
Construct Assembly 12
Alternative Method of Construct Assembly 13
Distraction and Compression 15
Final Tightening 16
Attach Transconnector 18
Optional Techniques 19
Implants 21
Instruments 24
Set list 30
Image intensifier control
Synthes Spine

Small Stature USS
Features and benefits
Low-profile system
– For pediatric and small-statured patients
– Designed to minimize soft tissue interactions
Dual (side)-opening, top-tightening
– Reduces inventory
– Simplifies intraoperative procedure
– No preloading implants onto rod
Technique adaptable
– Designed to correct scoliosis either by segmental
correction or global derotation
Biomechanical strength
–Comparable to the Universal Spinal System
Versatile linkage mechanism
– Allows addition or removal of anchorage points
to an assembled construct
2Synthes Spine Small Stature USS

Indications
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The Synthes USS (including the Click’X, USS VAS variable axis
components, and Pangea), Click’X Monoaxial, Pangea
Monoaxial, Dual-Opening and the Small Stature USS (which
includes small stature and pediatric patients) are noncervical
spinal fixation devices intended for use as posterior pedicle
screw fixation systems (T1–S2), aposterior hook fixation
system (T1–L5), or as an anterolateral fixation system (T8–L5).
Pedicle screw fixation is limited to skeletally mature patients
with the exception of the Small Stature USS. These devices
are indicated for all of the following indications regardless of
the intended use: degenerative disc disease (defined as disco-
genic back pain with degeneration of the disc confirmed by
history and radiographic studies), spondylolisthesis, trauma
(i.e., fracture or dislocation), deformities or curvatures (i.e.,
scoliosis, kyphosis, and/or lordosis, Scheuermann’s disease),
tumor, stenosis, pseudoarthrosis, and failed previous fusion.
When treating patients with degenerative disc disease (DDD),
transverse bars are not cleared for use as part of the posterior
pedicle screw construct.
When used with the 3.5 mm/6.0 mm parallel connectors,
the Synthes USS (including the Click'X, USS VAS variable axis
components, and Pangea), Click'X Monoaxial, Pange Mono-
axial, and Dual-Opening USS can be linked to the CerviFix
system. In addition, when used with 3.5 mm/5.0 mm parallel
connectors, the Synthes Small Stature USS, can be linked to
the CerviFix system. When used with the 5.0 mm /6.0 mm
parallel connectors, the Synthes Small Stature USS can be
linked to the Synthes USS (including the Click'X, USS VAS
variable axis components, and Pangea), the Click'X Monoax-
ial, PangeaMonoaxial, and Dual-Opening USS systems.
In addition, Synthes USS (including the Click’X, USS VAS
variable axis components, and Pangea), Click’X Monoaxial,
PangeaMonoaxial and the Dual-Opening USS can be inter-
changed with all USS 6.0 mm rods and transconnectors.

Preoperative Planning
4Synthes Spine Small Stature USS
1
Preoperative planning
Preoperative planning is critical in the preparation for spinal
surgery.
A radiographic evaluation (AP and lateral standing, and AP
lateral bending) should be completed for proper diagnosis
prior to surgical intervention.
Additional evaluation, such as CT scans, may be required if
there are any anatomic variations.
A preoperative planner may be used to plan the hook and
screw layout. A sample of the Small Stature USS planner is
shown on the right.
Small Stature USS Preoperative Planner
Dual-Opening Hooks*
Dual-Opening Screws*
Lamina Hooks
Side-opening Front-opening
Small x98.308 x98.309
Medium x98.318 x98.319
Large x98.328 x98.329
Posterior View
* I mplants are available in both Stainless Steel and Titanium.
Replace “X” with a “2” for Stainless Steel or “4” for Titanium.
Illustrations not shown actual size.
Tall Body Lamina Hooks
Side-opening Front-opening
Small x98.209 x98.210
Medium x98.211 x98.212
Large x98.213 x98.214
Thoracic Lamina Hooks
x98.338, Side-opening
x98.339, Front-opening
Transverse Process Hooks, Right
x98.376, Side-opening
x98.378, Front-opening
4.2 mm Screws
Length
x98.401 25 mm
x98.402 28 mm
x98.403 30 mm
x98.404 32 mm
x98.405 35 mm
x98.406 38 mm
x98.407 40 mm
5.0 mm Screws
Length
x98.409 25 mm
x98.410 30 mm
x98.411 35 mm
x98.412 40 mm
x98.413 45 mm
6.0 mm Screws
Length
x98.415 30 mm
x98.416 35 mm
x98.417 40 mm
x98.418 45 mm
x98.419 50 mm
x98.420 55 mm
7.0 mm Screws
Length
x98.422 30 mm
x98.423 35 mm
x98.424 40 mm
x98.426 45 mm
x98.427 50 mm
x98.428 55 mm
x98.429 60 mm
Transverse Process Hooks, Left
x98.377, Side-opening
x98.379, Front-opening
Angled Lamina Hooks
x98.206, Side-opening
x98.207, Front-opening
Pedicle Hooks
x98.348, Side-opening
x98.349, Front-opening
© SYNTHES Spine 2000
Right Left
Original Instruments and Implants of the Association for the Study of Internal Fixation–AO/ASIF SYNTHES and ASIF are registered trademarks of SYNTHES (USA) and SYNTHES AG Chur.
2
Prepare lamina
Instrument
388.521 LaminaFinder
Use the laminafinder to separate the ligamentum flavum
from the underside of the laminato ensure good bony
contact with the laminahook.

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Place Hook
3
Prepare pedicle
Instrument
388.511 Pedicle Finder
Using the pedicle finder, pierce the facet capsule and locate
the pedicle.
Remove asmall piece of the inferior articular process to
ensure proper seating of the pedicle hook (up-going only).
4
Place hook
Instruments
388.612 Hook/Screw Holder (“Hex Stick”)
388.622 Handle, for hook/screw holder
388.631 Hook Positioner
Align the hex on the “hex stick” holder with the hex in the
top of the appropriate hook and secure with the coupling
screw. Snap the “hex stick” into the handle by depressing
the button on the handle.
Place the hook in the desired location. The hook positioner
may also be used to facilitate placement of the hook.
After the hook is properly seated, remove the handle. The
“hex stick” can remain attached to the hook.

4
Place hook continued
Alternative Technique
Instrument
388.522 Hook Holding Forceps
Attach the appropriate hook to the hook holding forceps,
and place the hook in the desired location.
The hook positioner may be used to facilitate placement of
the hook.
After the hook is properly seated, remove the hook holding
forceps and repeat hook placement at each hook site, as
determined in the preoperative plan.
5
Place remaining hooks
Repeat Steps 2–4 to place hooks at each hook site, as deter-
mined in the preoperative plan.
6Synthes Spine Small Stature USS
Place Hook continued

7
Prepare pedicle
Instruments
388.54 Probe
388.544 Pedicle Probe, for 4.2 mm screws
388.545 Straight Ball Tip Probe
388.546 Curved Ball Tip Probe
388.55 Awl
388.551 Awl, for 4.2 mm screws
Use the awl or awl for 4.2 mm screws to perforate the
posterior cortex of the pedicle.
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Prepare Pedicle
6
Identify pedicles
The entry point for each lumbar pedicle is at the intersection
of ahorizontal line bisecting the transverse process and a
vertical line drawn along the lateral border of the superior
articular process.
The point of entry for each thoracic pedicle is at the intersec-
tion of aline through the transverse processes and aline
through the inferolateral edge of the facet joint.

Prepare Pedicle continued
8Synthes Spine Small Stature USS
7
Prepare pedicle continued
Open the pedicle canal, using the probe or the pedicle probe
for 4.2 mm screws. Displace the soft cancellous bone by ad-
vancing the probe into the pedicle canal. If the probe resists
advancement, use radiographic imaging to check position
and orientation. Care should be taken to not perforate the
walls of the pedicle.
Palpate the walls of the pedicle using astraight ball tip probe
or curved ball tip probe. Use radiographic imaging to confirm
position and orientation.
8
Select proper screw length
Instrument
388.545 Straight Ball Tip Probe
Place the straight ball tip probe into the pedicle canal to
determine proper screw length.
This instrument has depth markings at 25 mm, 30 mm,
40 mm, 50 mm, 60 mm and 70 mm.
Position all screws approximately 50–80% into the vertebral
body.*
* M.E. Müller, M. Allgöwer, R. Schneider, H. Willenegger, Manual of Internal
Fixation, 3rd Edition (Berlin: Springer-Verlag, 1991): p. 668.