Synthes USS II User manual

USS II. Comprehensive posterior and
anterior deformity system with screws
and hooks with dual opening.
Handling technique

Introduction
Handling Technique
Table of Contents
USS II Screws and Hooks with Dual Opening 2
Indications and Contraindications 4
Implant Handling Using the Stick 5
Insert Pedicle Screw* 7
Position Pedicle Hook* 13
Position Lamina Hook* 18
Angled Lamina Hook* Positioning 20
Rod Contouring 22
Locking Implants to Rods
Variation A: Place Sleeve and Nut Consecutively 24
Variation B: Place Sleeve and Nut in a Single Operation 27
Variation C: Rod Introduction Pliers (“Persuader”) 30
Final Tightening of Nut 35
Distraction or Compression of Adjacent Implants 36
Insertion of Vertebral Body Screws with Washer 38
(Anterior Approach)
Optional: Attach Anterior Connecting Clamp 41
Connecting Rod and Implant Using Rod Connector 44
Connecting Two Rods
Variation A: Connecting Two 6 mm Rods
with Cross-link Clamp 46
Variation B: Connecting Two 6 mm Rods
with Low-Profile Transverse Connectors 49
Variation C: Connecting Two 5 mm Rods
with Transverse Connectors 50
*Screws and hooks are also referred to in this guide as “implant”

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Product Information
Bibliography
Implants 54
Instruments 61
72
Image intensifier control
Warning
This description alone does not provide sufficient background for direct use of
the product. Instruction by a surgeon experienced in handling this product is
highly recommended.
Note
Both the segmental derotation principle and the classic derotation method based
on the Cotrel-Dubousset technique can be used for scoliosis correction using
the USS Universal Spine System. Segmental corrections may be implemented or the
spinal column may be realigned along a sagittally positioned rod.
Reprocessing, Care and Maintenance of
Synthes Instruments
For general guidelines, function control and dismantling of multi-part instruments,
please refer to: www.synthes.com/reprocessing

1 mm
Synthes dual-core pedicle screws can
be screwed in as fast as high-pitch
screws and offer additional high grip.
High pull-out resistance
Dual-core pedicle screws are easy to in-
sert and can be turned back for final
precision adjustment without losing
their secure anchorage.
USS II. Comprehensive posterior and
anterior deformity system with screws
and hooks with dual opening.
2 Synthes USS II Handling technique
Flexible
Implants accept 5 mm or 6 mm rods
and are locked with the same nut
(Fig. 1)
Bilateral option for fixing the implants
to the rod (Fig. 2)
Screws with special thread geometry
for anterior stabilization (Fig. 3)
Anatomical
– Low profile protects soft tissue
– Firm anchorage of pedicle hooks
with patented screw technology
Fast and secure
– Dual-core core screw design for
stable anchorage and double-lead
thread design for screwing in fast
– Immediate and controlled grip of the
screw in the bone owing to the
thread extending to the tip
– Excellent tactile feedback of screw
grip in the bone owing to the combi-
nation of double-lead thread and
dual core
Fig. 2 Fig. 3Fig. 1
Screw with 5 mm
rod
Screw with 6.0 mm
rod
4 mm
strong
1 Revolution
Grip
double
high
Thread
Pitch

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Proven correction and fixation technique
Various instruments for screw/rod reduction
Controlled implant manipulation using hook- and
screwholder (“stick”) with hexagonal coupling and
handle.
Simple to mount and remove
Quick handle assembly
Controlled rod-implant assembly
with the “Persuader”
Immediate fixation with sleeve
Counter torque easy to position
Secure sleeve purchase
Good seat on the rod

Intended use
The USS II System is a posterior pedicle screw and hook sys-
tem (T1–S2), developed for precise and segmental stabiliza-
tion of the spine. Anterior cancellous bone screws can also
be used in the thoracolumbar spine.
Indications
– Spinal deformities (congenital, idiopathic, neuromuscular)
– Degenerative diseases
– Tumors
– Fractures
Contraindications
– Additional anterior support or reconstruction of the spine
is required in the case of fracture and tumors with poor
ventral support.
– Osteoporosis
Case example 1, posterior fixation with USS II
– 16-year-old female patient with severe kyphoscoliosis
– Posterior instrumentation with pedicle screws in L1 to L5
and pedicle, lamina and transverse process hooks in T2 to
T10 after ventral release
Case example 2, anterior fixation with USS II anterior
– 11-year-old female patient with adolescent idiopathic
scoliosis, standing Cobb angle 75°, bending Cobb angle
40°
– Anterior correction from T5 to T10
Indications and Contraindications
4 Synthes USS II Handling technique
Preoperative, scoliotic
double curve, thoracic
78°, lumbar 68°
Postoperative, thoracic
38°, lumbar 38°
Preoperative Postoperative

The screws with dual openings have the same head as the
pedicle, lamina and transverse process hooks. The following
handling tips therefore apply both to the pedicle screws and
anterior vertebral body screws, and to all three types of hook
(referred to below as implants).
Instruments
388.622 Handle for USS Hook and Screwholder
No. 388.612
388.612 USS Hook and Screwholder,
with hexagonal socket 4.0 mm
Implant Handling Using the Stick
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1
Attach handle to stick
Press the knurled release button on the top end of the
handle and simultaneously push the USS hook and
screwholder, known as the “stick”, into the handle.

6 Synthes USS II Handling technique
Implant Handling Using the Stick
2
Pick up implant
Insert stick into implant. Turn release button in a clockwise
direction and pick up the implant.
3
Release handle from stick
Insert the implant. Press the release button on the handle to
detach the handle from the stick.

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Insert Pedicle Screw
Instruments
388.551 Pedicle Awl 3.0 mm, length 230 mm,
for Screws 4.2 mm
388.550 Pedicle Awl 4.0 mm, length 230 mm,
for Pedicle Screws 4.0 to 7.0 mm
388.538 Pedicle Probe 2.8 mm, length 230 mm,
for Pedicle Screws 4.2 mm
388.540 Pedicle Probe 3.8 mm, length 230 mm,
for Pedicle Screws 5.2 and 6.2 mm
388.539 Pedicle Probe 4.8 mm with Canevasit
Handle, length 230 mm,
for Pedicle Screws 8.0 and 9.0 mm
357.789 Depth gauge for Pedicle Screws 4.2
to 9.0 mm
388.545 Feeler for Screw Channel, straight,
2.3 mm, length 275 mm
388.546 Feeler for Screw Channel, curved,
2.3 mm, length 275 mm
388.622 Handle for USS Hook and Screwholder
No. 388.612
388.612 USS Hook and Screwholder,
with hexagonal socket 4.0 mm
Optional instruments
388.608 Pedicle Marker USS II,
with spherical bulges
388.609 Pedicle Marker USS II, with long bulges

7–10°
10–20°
10–15° 10–15°
5–10° 5–10°
7–10°
12
3
45a
5b
8 Synthes USS II Handling technique
1
Determine entry point and position of pedicle screw
a. Thoracic spine
The entry points are located directly at the lower margin of
the superior facet joint (1). Insert the screw at an angle
of 7–10° to the midline (2) and 10–20° caudally (3).
b. Lumbar spine
The entry points are located at the intersection of the vertical
line (this runs at a tangent to the lateral edge of the superior
articular process) and the horizontal line that intersects the
transverse process (4).
Insert the screw at the thoracolumbar junction at an angle of
5–10° to the midline (5a). Insert the screw at the L2– L5 level
at an angle of 10–15° (5b).
Insert Pedicle Screw

1
2
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2
Open pedicle and determine screw length
Use one of the awls to open the pedicle cortex to a depth of
10 mm (1). Open the pedicle further using one of the USS
pedicle probes with markings at 30, 40 and 50 mm (2).
 Screw Pedicle Awl Pedicle Probe
(mm)
4.2 388.551 388.538 (2.8 mm)
5.2, 6.2 388.550 388.540 (3.8 mm)
7.0 388.550 388.539 (4.8 mm)

1
10 Synthes USS II Handling technique
Determine the length of the pedicle screw with the depth
gauge for pedicle screws.
3
Probe pedicle channel
Use the straight or curved feeler to probe the pedicle screw
channel to check the wall for perforations. (1)
Insert Pedicle Screw

10 mm
10 mm
2
3
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Optional: use of pedicle markers
Use a pedicle marker with spherical bulges and/or a pedicle
marker with long bulges to verify the position and alignment
radiographically (2). The bulges show the depth at 10 mm in-
tervals (3). The use of pedicle markers with bulges of two dif-
ferent shapes facilitates differentiation between the left and
right pedicle.

1
2
Insert Pedicle Screw
12 Synthes USS II Handling technique
4
Insert pedicle screw into pedicle
Pick up the pedicle screw as described on page 5 and 6. In-
sert the pedicle screw into the prepared pedicle until the
screw head is well seated and one of the openings points to-
wards the rod that is to be subsequently inserted (1). Press
the release button to detach the handle from the stick (2).
Note: If using a rod connector, align the screw head such
that one of the openings is perpendicular to the rod.

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Position Pedicle Hook
Instruments
388.510 USS Pedicle Feeler, length 300 mm
388.622 Handle for USS Hook and Screwholder
No. 388.612
388.612 USS Hook and Screwholder,
with hexagonal socket 4.0 mm
388.632 Hook Positioner for USS II
315.190 Dill Bit 2.0 mm, length 100/75 mm,
3-flute, for Quick Coupling
388.581 USS Drill Sleeve 2.0
387.060 Handle for Drill Sleeve 2.0
319.060 Depth Gauge for Screws 1.5 to 2.0 mm,
measuring range up to 38 mm
388.381 Holding Sleeve for Fillister Head Screws
314.070 Screwdriver, hexagonal, small, 2.5 mm,
with groove
Optional instruments
388.512 USS II Pedicle Feeler, length 300 mm,
for small hooks
388.530 USS Chisel, width 9 mm
The special feature of USS pedicle hooks is the fact that they
can be anchored securely in the pedicle with a single
screw and exhibit high pull-out strength, comparable to the
pull-out strength of a 6.2 mm pedicle screw.

1
2
14 Synthes USS II Handling technique
1
Prepare seat for pedicle hook
Prepare the pedicle with the USS pedicle feeler (1). Place the
pedicle feeler between the inferior and superior articular
facets. Ensure that the feeler is placed in the articular space
and not in the bone of the inferior facet.
To facilitate the insertion of the pedicle hook, remove a small
portion of the inferior facet with an osteotome (2). There
are six marks on the pedicle feeler; once the last one has
been reached, sufficient bone has been removed to position
the hook about the pedicle.
Move the feeler in a lateral and cranial direction to check for
the optimum position. Do not push medially.
Remove the pedicle feeler.
Position Pedicle Hook

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2
Position pedicle hook
Pick up the pedicle hook as described on page 5 and 6.
Note: Use a front-opening hook if a rod connector is re-
quired to connect the hook to the longitudinal rod.
Insert the hook positioner for USS II into the screw hole of
the pedicle hook and move the hook into the prepared posi-
tion.
Ensure that the pedicle hook is snug around the pedicle by
pushing the hook positioner axially and laterally. If it does not
move, the pedicle hook is correctly seated.
Gently tap the hook positioner with a hammer to firmly seat
the hook.
Remove the hook positioner and the handle. The stick re-
mains attached to the hook.

Position Pedicle Hook
16 Synthes USS II Handling technique
3
Drill hole for screw 3.2 mm and determine
the screw length
A screw 3.2 mm may be inserted through the hole in the
back of the hook to fit the pedicle hook in the pedicle tightly.
Use the 3-flute drill bit 2.0 mm with the USS drill sleeve
2.0 and an oscillating drill to drill the screw hole. The drill
sleeve consists of two parts, the sleeve and the handle. These
two components must be screwed together before use.
Note: Do not start the power drill if the bit does not hit
bone after passing through the drill sleeve.
Remove the drill sleeve and determine the depth of the hole
using the depth gauge.

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4
Insert screw 3.2 mm
Pick up a suitable screw for the pedicle hook with the hold-
ing sleeve and the hexagonal screwdriver, and insert it in
the pre-drilled hole. The pedicle hook is now firmly attached
to the pedicle.

18 Synthes USS II Handling technique
Instruments
388.520 USS Lamina Feeler, length 300 mm
388.622 Handle for USS Hook and Screwholder
No. 388.612
388.612 USS Hook and Screwholder,
with Hexagonal Socket 4.0 mm
388.632 Hook Positioner for USS II
Optional instrument
388.521 USS Small Stature/Paediatric Lamina Feeler
1
Prepare seat for lamina hook
The lamina hook can be placed around either the superior or
inferior portion of the lamina. Prepare the seat for the lamina
hook using a lamina feeler. Carefully remove the ligamentum
flavum and a small portion of the lamina with a rongeur to
ensure good seating of the lamina hook.
Remove the lamina feeler.
Position Lamina Hook