Zimmer Biomet Headless Compressionand Twist-Off Screws User manual

Headless Compression
and Twist-O Screws
Surgical Technique

1 | Headless Compression and Twist-O Screws Surgical Technique
Table of Contents
Headless Compression Screw.......................................................................... 2
Incision....................................................................................................................... 3
Lateral Release ........................................................................................................... 3
Unicortical Applications ........................................................................................... 4
Osteotomy ................................................................................................................. 4
K-Wire Placement....................................................................................................... 5
Screw Measurement................................................................................................... 6
Insertion..................................................................................................................... 7
Drilling (Optional)....................................................................................................... 7
Screw Removal ........................................................................................................... 7
Bicortical Osteotomy................................................................................................ 8
K-Wire Placement....................................................................................................... 8
Drilling (Optional)....................................................................................................... 8
Insertion..................................................................................................................... 9
Screw Removal ........................................................................................................... 9
Twist-O Screw .................................................................................................. 10
Surgical Approach .................................................................................................... 11
Osteotomy ............................................................................................................... 11
Insertion................................................................................................................... 12
Final Step ................................................................................................................. 14
Ordering Information ....................................................................................... 15
Indications and Contraindications................................................................ 17

2 | Headless Compression and Twist-O Screws Surgical Technique
2.5 mm
10-40 mm (2 mm increments)
3.0 mm
10-40 mm (2 mm increments)
Tapered Threads
0.9 mm Cobalt Chrome K-Wire
T7 Hexalobe Drive
Four Cutting Edges
TiMAX®Titanium
1.8 mm minor diameter
designed for increased
strength over prior screw1
Headless Compression Screws

3 | Headless Compression and Twist-O Screws Surgical Technique
Figure 1
The following surgical technique describes the use of
a Headless Compression Screw for a distal Chevron
osteotomy of the first metatarsal or various types of
osteotomies (Figure 1).
Incision
A 7 cm incision is centered over the dorsal aspect of
the first metatarsophalangeal joint, just medial and
parallel to the EHL tendon. The incision is carried
down to the subcutaneous tissues (Figure 2). Retract
the soft tissues carefully being certain to protect the
neurovascular bundle in the skin flap.
Lateral Release
If necessary, a standard lateral release is performed
through the same incision. This includes the release
of the adductor tendon and the fibular sesamoidal
ligament.
Figure 2
Headless Compression Screw Technique

4 | Headless Compression and Twist-O Screws Surgical Technique
Osteotomy
A linear capsulotomy is then used to expose the
joint. The hypertrophic medial eminence on the 1st
metatarsal head is then osteotomized (Figure 3).
Insert a 0.9 mm k-wire perpendicular into the center
of the first metatarsal head (Figure 3a).
A medially based long arm Chevron type osteotomy
is then created from medial to lateral. Remove
the k-wire. The capital fragment is then mobilized
and transposed laterally to correct the 1st IMA and
impacted on the 1st metatarsal shaft (Figure 3b).
Figure 3 Figure 3b
Figure 3a
Headless Compression Screw Technique – Unicortical Applications

5 | Headless Compression and Twist-O Screws Surgical Technique
K-Wire Placement
The osteotomy is then stabilized in a uni-cortical
application, such as a distal Chevron osteotomy, by
advancing the 0.9 mm K-Wire across the osteotomy
site until the tip is visible. Retract the wire slightly, so
the tip is below the articular cartilage (Figure 4). Verify
k-wire position via fluoroscopy.
Note: It is recommended to subtract 3-4 mm from
the depth gauge measurement to avoid penetrating
the articular cartilage with the distal tip of the
screw. For example, if the measurement is 20 mm
then select the 16 mm screw.
Tip: When using a screw longer than 28 mm for
oblique applications, it may be beneficial to use a 0.9
mm x 105 mm k-wire.
Tip: For hammertoe applications, a sterile double
tipped 0.9 mm x 152 mm k-wire is available for order.
Figure 4
Headless Compression Screw Technique – Unicortical Applications
0.9 x 70 mm K-wire Cobalt Chrome
0.9 x 105 mm Sterile K-wire Cobalt Chrome
0.9 x 152 mm Trocar Sterile K-wire Stainless Steel
K-Wire Options

6 | Headless Compression and Twist-O Screws Surgical Technique
Figure 5
Screw Measurement
The length of the screws is measured using the depth
gauge. Slide the depth gauge over the 0.9 mm k-wire
down to bone ensuring the depth gauge is sitting flush
against bone.
Note: The depth gauge is only compatible with the
0.9 mm x 70 mm and 0.9 mm x 105 mm k-wires.
The depth gauge displays the measurement from the
distal tip of the depth gauge to the tip of the k-wire.
Important: The screw length may vary depending
upon the level of obliquity applied to the k-wire
during insertion. To determine the screw length, and
with the obliquity of the k-wire in mind, record the
measurement. Using the K-Wire Obliquity Chart
below, subtract the corresponding milimeters from
the recorded measurement (Figure 5).
It is recommended that each screw length be verified
o the screw caddy measurement slot before the
screw is implanted.
90° degrees 45° degrees 22.5° degrees
K-Wire Obliquity
90 degrees Subtract 0 mm from measurement
45 degrees Subtract 2 mm from measurement
22.5 degrees Subtract 5-6 mm from measurement
Headless Compression Screw Technique – Unicortical Applications

7 | Headless Compression and Twist-O Screws Surgical Technique
Insertion
Load the screw onto the T7 Cannulated Driver and
Mini Rachet Handle. Place screw over the 0.9 mm
k-wire down to surface of bone. Advance the screw
into bone by turning the T7 Cannulated Driver
clockwise (Figure 6). Continue advancing until
the head of the screw is at or just below the near
cortex. After compression is achieved, remove the T7
Cannulated Driver and 0.9 mm k-wire. Verify screw
position with fluoroscopy (Figure 7).
Drilling (Optional)
Note: The Zimmer Biomet Headless Compression
screws are designed to be self-drilling and self-
tapping, and may be inserted under power.
If the bone is deemed to be too hard prior to screw
insertion, or an oblique approach is required, use a
Head Relief Drill to prepare the near cortex. For the
2.5 mm screw use the 2.5 mm Head Relief Drill, and
for the 3.0 mm screw, use the 3.0 mm Head Relief Drill
(Figure 8).
Screw Removal
For screw removal, insert the T7 Solid Driver into the
head of the screw, and turn the Driver counterclockwise
until the screw is removed.
Figure 8Figure 6
Figure 7
2.5 mm Head Relief Drill AO
110 02774 6
3.0 mm Head Relief Drill AO
110 027747
Headless Compression Screw Technique – Unicortical Applications

8 | Headless Compression and Twist-O Screws Surgical Technique
Drilling (Optional)
Note: The Zimmer Biomet Headless Compression
screws are designed to be self-drilling and self-
tapping, and may be inserted under power.
If the bone is deemed to be too hard, or an oblique
approach is required, use a Head Relief Drill to prepare
the near cortex.
Tip: For the 2.5 mm screw use the 2.5 mm Head Relief
Drill, and for the 3.0 mm screw, use the 3.0 mm Head
Relief Drill (Figure 10).
Headless Compression Screw Technique – Bicortical Applications
Figure 9
K-Wire Placement
For bi-cortical applications, such as the Scarf-Z or
Ludlo osteotomy, insert the k-wire until the tip
begins to exit the outer wall of the far cortex (Figure 9).
Screw measurement subtraction is not necessary for
bi-cortical fixation.
0.9 x 70 mm K-wire Cobalt Chrome
0.9 x 105 mm Sterile K-wire Cobalt Chrome
0.9 x 152 mm Trocar Sterile K-wire Stainless Steel
K-Wire Options
Figure 10

9 | Headless Compression and Twist-O Screws Surgical Technique
Insertion
Load the screw onto the T7 Cannulated Driver and Mini
Rachet Handle. Place screw over the 0.9 mm k-wire
down to surface of bone. Advance the screw into
bone by turning the T7 Cannulated Driver clockwise.
Continue advancing until the head of the screw is at
or just below the near cortex. After compression is
achieved, remove the T7 Cannulated Driver and 0.9
mm k-wire. Verify screw position with fluoroscopy.
Screw Removal
For screw removal, insert the T7 Solid Driver into the
head of the screw, and turn the Driver counterclockwise
until the screw is removed.
2.0 x 65 mm Cann Drill Bit AO 110027744
Compatible with the
70 mm and longer k-wires
2.0 x 80 mm Cann Drill Bit AO 110018532
compatible with the
105 mm and longer k-wires
2.5 mm Head Relief Drill AO
110 02774 6
3.0 mm Head Relief Drill AO
110 027747
Headless Compression Screw Technique – Bicortical Applications
Figure 11
Drilling (Optional) (cont.)
In situations where bi-cortical lagging is required (such
as a Scarf-Z Osteotomy), use the 2.0 mm Cannulated
AO Drill for preparation of the far cortex (Figure 11).
The medial cortical shelf and metatarsal head are then
osteotomized and rasped to a smooth contour.

10 | Headless Compression and Twist-O Screws Surgical Technique
2.0 mm Screw
8 mm-15 mm (1 mm increments)
2.7 mm Screw
8 mm-16 mm (1 mm increments)
18-24 mm (2 mm increments)
Expanded shaft length
over previous design
for use with pin drivers
3 point head engagement
designed for stable driving
Cortical threads Cancellous threads
Cutting tip designed to maximize
far cortex purchase
Twist-O Screws

11 | Headless Compression and Twist-O Screws Surgical Technique
Figure 1 Figure 2
The following surgical technique describes a Twist-O
Screw being used in a Weil osteotomy.
Surgical Approach
A Weil osteotomy is performed using a dorsal approach.
Incision is initiated within the intermetatarsal space
and extends to the web space ( Figure 1). Osteotomy
skin retraction provides exposure of both extensor
muscles.
Place the lesser metatarsal in plantar flexion to expose
the metatarsal head and dislocate the joint. Placing
one Hohmann retractor on each side of the metatarsal
should make this maneuver much easier. The use
of a spreader helps to ensure a safe osteotomy by
providing adequate protection.
Osteotomy
The osteotomy is made horizontal and parallel to the
sole. It starts in the cartilage of the head, near the
dorsal margin, and should be at least 2.5 cm long
(Figure 2).
Caution: The direction of the cut should be adjusted
according to the condition of the forefoot. In case of
pes cavus, the cut may be too short and the resection
level should therefore be raised. In case of pes planus
(or for the fourth or fifth metatarsals), the cut may be
too long and the resection level should be lowered.
Twist-O Screw Technique

12 | Headless Compression and Twist-O Screws Surgical Technique
Figure 4
Osteotomy (cont.)
Once the osteotomy has been completed, slide the
plantar segment of the metatarsal head proximally to
the desired position (Figure 3).
Note: For applications other than a Weil osteotomy,
it may be necessary to measure for screw length
prior to insertion. To do so, insert the 0.9 mm
k-wire across the osteotomy to the desired depth.
Slide the depth gauge over the k-wire ensuring that
it is sitting flush with the bone. The depth gauge
displays the measurement from the distal tip of the
depth gauge to the top of the k-wire.
Figure 3 Figure 5
Insertion
Hold the head against the metatarsal with the
forefinger. The placement of a dorsal clamp aids
in accurate head positioning and desired fixation.
Using the Pin Driver on the Twist-O Screw, drive the
screw into the bone slowly under power at the same
trajectory as was the k-wire (Figure 4).
Note: To reduce the potential for the tip of the
screw to slide down the bone while under power,
perforate the near cortex with the 0.9 mm k-wire
prior to screw insertion (Figure 5).
Twist-O Screw Technique

13 | Headless Compression and Twist-O Screws Surgical Technique
Insertion (cont.)
Once the screw head engages the dorsal cortex, the
support prongs are designed to snap o (Figure 6).
Figure 6
Twist-O Screw Technique
If inserting the Twist-O Screw in osteoporotic bone,
stop advancing the screw before the head engages
the near cortex. Place the mosquito clamp against
the screw, below the head, applying pressure while
bending the pin driver towards the mosquito clamp
(Figure 7), until the shaft breaks o from the screw
head.
Place the Twist-O Finishing Driver on the Mini Rachet
Handle and finish screw placement by hand (Figure 8).
Figure 8
Figure 7

14 | Headless Compression and Twist-O Screws Surgical Technique
Final Step
Resection of the dorsal peak is the final step of this
procedure (Figure 9). Despite shortening, Z-shaped
release of extensor muscles is often necessary. Close
the incision.
Note: The 2.0 mm Twist-O Screw is designed with
cortical threads, while the 2.7 mm Twist-O Screw
has cancellous threads for use in softer bone and
is designed for increased purchase (Figure 10).
Figure 9 Figure 10
2.0 mm Cortical
2.7 mm Cancellous
Twist-O Screw Technique

15 | Headless Compression and Twist-O Screws Surgical Technique
2.5 mm Screws, Fully Threaded
Non-Sterile Description
110 018 415
110 018 416*
110 018 417 *
110018418*
110 018 419 *
110 018 4 20 *
110 018 4 21*
110 018 4 2 2 *
110 018 4 2 3 *
110 018 52 8
110018529
110 018 53 0
110 018 55 0
110018551
110018552
110 018 55 3
HCS Screw 2.5 x 10
HCS Screw 2.5 x 12
HCS Screw 2.5 x 14
HCS Screw 2.5 x 16
HCS Screw 2.5 x 18
HCS Screw 2.5 x 20
HCS Screw 2.5 x 22
HCS Screw 2.5 x 24
HCS Screw 2.5 x 26
HCS Screw 2.5 x 28
HCS Screw 2.5 x 30
HCS Screw 2.5 x 32
HCS Screw 2.5 x 34
HCS Screw 2.5 x 36
HCS Screw 2.5 x 38
HCS Screw 2.5 x 40
*Included in tray
2.5 mm Screws, Partially Threaded
Non-Sterile Description
110 018 4 24
110 018 4 2 5
110 018 4 26
110 018 4 27
110 018 4 28
110 018 4 29
110 018 4 30
HCS Screw 2.5 x 28 PT
HCS Screw 2.5 x 30 PT
HCS Screw 2.5 x 32 PT
HCS Screw 2.5 x 34 PT
HCS Screw 2.5 x 36 PT
HCS Screw 2.5 x 38 PT
HCS Screw 2.5 x 40 PT
3.0 mm Screws, Fully Threaded
Non-Sterile Description
110018448
110 018 4 4 9*
110 018 4 50 *
110018451*
110 018 4 52*
110018453*
110 018 4 5 4*
110 018 4 55*
110 018 4 56*
110018457*
110 018 4 58 *
110018459*
110 018 4 6 0 *
110 018 4 61
110 018 4 6 2
110 018 4 6 3
HCS Screw 3.0 x 10
HCS Screw 3.0 x 12
HCS Screw 3.0 x 14
HCS Screw 3.0 x 16
HCS Screw 3.0 x 18
HCS Screw 3.0 x 20
HCS Screw 3.0 x 22
HCS Screw 3.0 x 24
HCS Screw 3.0 x 26
HCS Screw 3.0 x 28
HCS Screw 3.0 x 30
HCS Screw 3.0 x 32
HCS Screw 3.0 x 34
HCS Screw 3.0 x 36
HCS Screw 3.0 x 38
HCS Screw 3.0 x 40
*Included in tray
Implants – Headless Compression Screws
Ordering Information

16 | Headless Compression and Twist-O Screws Surgical Technique
2.0 mm Twist-O Screws (Cortical)
Non-Sterile Description
110018481
110018482
110018483*
110018484*
110018485*
110018486*
110018487*
110018488*
Twist-O Screw 2.0 x 8
Twist-O Screw 2.0 x 9
Twist-O Screw 2.0 x 10
Twist-O Screw 2.0 x 11
Twist-O Screw 2.0 x 12
Twist-O Screw 2.0 x 13
Twist-O Screw 2.0 x 14
Twist-O Screw 2.0 x 15
*Included in tray
2.7 mm Twist-O Screws (Cancellous)
Non-Sterile Description
110 018 4 9 8
110 018 4 9 9
110018500*
110018501*
110018502*
110 018 50 3*
110 018 5 0 4*
110 018 50 5*
110 018 5 0 6*
110 018 5 0 8*
110 018 5 0 9*
110018510*
110 018 511*
Twist-O Screw 2.7 x 8
Twist-O Screw 2.7 x 9
Twist-O Screw 2.7 x 10
Twist-O Screw 2.7 x 11
Twist-O Screw 2.7 x 12
Twist-O Screw 2.7 x 13
Twist-O Screw 2.7 x 14
Twist-O Screw 2.7 x 15
Twist-O Screw 2.7 x 16
Twist-O Screw 2.7 x 18
Twist-O Screw 2.7 x 20
Twist-O Screw 2.7 x 22
Twist-O Screw 2.7 x 24
*Included in tray
Implants – Twist-O Screws
Instruments & Disposables
Instruments
Non-Sterile Description
110 018 531
110 018 53 5
PA017†
110 018 537
110 018 5 41
PA720
110 0174 0 6
110 018 53 9
110 018 53 8
110 018 561
110 018 56 2
T7 Driver Cannulated AO
Depth Gauge
Screw Forceps
T/O Finishing Driver AO
T7 Driver Solid AO
Osteotomy Clamp
Mini 4 Sided Ratchet Handle, Secure AO
Implant and Instrument Case
Implant and Instrument Lid
HCS Screw Caddy
Twist-O Screw Caddy
†item is sterile packed only
Disposables
Non-Sterile Description
110 018 526
110 018 532
110 027 74 4
110 02 774 6
110 027 747
–
–
0.9 x 70 mm K-wire
2.0 x 80 mm Cann Drill Bit AO
2.0 x 65 mm Cann Drill Bit AO
2.5 mm Head Relief Drill AO
3.0 mm Head Relief Drill AO
0.9 x 105 mm Sterile K-wire
0.9 x 152 mm Trocar Sterile K-wire
Ordering Information

17 | Headless Compression and Twist-O Screws Surgical Technique
INDICATIONS
The Zimmer Biomet Headless Compression Screws
and Twist-O Screws are indicated for fixation of
bone fractures, fusion of a joint (arthrodesis) or bone
reconstruction (osteotomy) of the mid-foot bones,
metatarsal and phalanges of the foot or the phalanges,
metacarpals and carpals of the hand. In the foot, these
include procedures to correct Hallux Valgus (bunions),
Hallux Varus and Hallux Rigidus, Hammer toe, Claw
toe and Mallet toe.
CONTRAINDICATIONS
1. Infections.
2. Patient conditions including blood supply
limitations, insucient quantity or quality
of bone.
3. Patients with mental or neurologic conditions
who are unwilling or incapable of following
postoperative care instructions.
4. Foreign body sensitivity where material
sensitivity is suspected, testing is to be
completed prior to implantation of the device.
Indications and Contraindications

References
1. FRS Update (FRS and Twist-O screws) Design Rationale. FX000090
Rev. C. Bending strength analysis is not necessarily indicative of
clinical performance.
This material is intended for health care professionals and the Zimmer
Biomet sales force only. Distribution to any other recipient is prohibited.
All content herein is protected by copyright, trademarks and other
intellectual property rights owned by or licensed to Zimmer Biomet
or its aliates unless otherwise indicated. This material must not be
redistributed, duplicated or disclosed, in whole or in part, without the
express written consent of Zimmer Biomet.
Check for country product clearances and reference product specific
instructions for use. For complete product information, including
indications, contraindications, warnings, precautions, and potential
adverse eects, see the package insert and www.zimmerbiomet.com.
This technique was prepared in conjunction with a licensed health
care professional. Zimmer Biomet does not practice medicine and
does not recommend any particular orthopedic implant or surgical
technique for use on a specific patient. Information on the products
and procedures contained in this document are of a general nature and
does not constitute medical advice or recommendations. The surgeon is
responsible for determining the appropriate device(s) and technique(s)
for each individual patient and this document does not replace the need
for examination and/or advice in whole or its part by a surgeon.
CE Mark on the surgical technique is not valid unless there is a CE Mark
on the product (description) label.
©2016 Zimmer Biomet
BMET1228.0 • REV0616
Authorized Representative
Biomet UK Ltd.
Waterton Industrial Estate
Bridgend, South Wales
CF31 3XA
UK
Legal Manufacturer
Biomet Trauma
P.O. Box 587
56 E. Bell Drive
Warsaw, Indiana 46581-0587
USA
www.zimmerbiomet.com
CE mark on a surgical technique
is not valid unless there is a CE
mark on the product label.
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