Synthes MultiLoc Proximal Humeral Nail User manual

MultiLoc Proximal Humeral Nail.
Proximal humeral nail with multiple
locking options for simple and complex
fractures.
Technique Guide

Introduction
Surgical Technique
Product Information
Image intensifier control
MultiLoc Proximal Humeral Nail Technique Guide Synthes
Table of Contents
MultiLoc Proximal Humeral Nail 2
Screw Configuration 4
AO Principles 5
Indications 6
Clinical Cases 7
Patient Positioning 10
Approach 11
Opening the Humerus 13
Nail Insertion 16
Nail Positioning 18
Proximal Locking 22
MultiLoc Screws 22
3.5 mm Locking Screws 26
Distal Locking 30
End Cap Insertion 34
Implant Removal (Optional) 37
Implants 40
Instruments 45
Set Lists 54

MultiLoc Screws
1Blunt screw tips to minimize the risks
associated with secondary screw
perforation
2Countersunk screwheads to reduce
implant prominence
3Four suture holes per screw, for
attachment of the rotator cuff muscles
4Option for secondary 3.5 mm locking
screws, for improved stability where
needed*
MultiLoc Proximal Humeral Nail.
2 Synthes MultiLoc Proximal Humeral Nail Technique Guide
Proximal humeral nail with multiple locking options for
simple and complex fractures.
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MultiLoc Proximal Humeral Nail
– Cannulated nails in right and left
designs, 8.0 mm and 9.5 mm diame-
ters, and 160 mm length, to ensure
optimal fit in the canal
– Straight nail for central insertion
point, to avoid potential insertion
through the fracture site, increasing
biomechanical stability
Angular Stable Locking System ASLS
(optional)
Improved fixation in poor bone quality.
MultiLoc Proximal Humeral Nail Technique Guide Synthes 3
* Comparative testing was conducted by Synthes
with the MultiLoc Humeral Nail construct
implanted in polyurethane foam block material of
multiple densities. Static bend testing was
conducted to compare the stability of the nail
construct with and without the secondary 3.5 mm
locking screws assembled with the proximal
lateromedial (LM) screws. The static bending force
was applied to the test constructs in an eccentric,
mediolateral direction.Testing was conducted with
the test sample constructs implanted in foam block
material with densities of 5.5 pcf (pounds per
cubic foot), 7.5 pcf, and 10 pcf. Failure was
defined as varus collapse of 10 mm or cutout of
the proximal screws. Results showed as much as a
45% increase in construct stability when the
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– Ascending screw option to provide
support to the calcar
– Multiplanar distal locking options for
less implant toggling in the medullary
canal
– Fully targeted locking options for
accurate screw insertion
– Polyethylene inlay for secure screw
fixation
secondary 3.5 mm locking screws were assembled
with the proximal LM screws and the construct
was subjected to the static mediolateral bending
force. Test results showed that in 10 pcf foam
material, the MultiLoc Humeral Nail construct
failed at 315 N (mean) with secondary locking
screws assembled with LM screws vs. 230 N
(mean) without secondary locking screws. In 7.5
pcf foam material, the construct failure occurred at
141 N (mean) with secondary 3.5 mm locking
screws vs 123 N (mean) without secondary 3.5 mm
locking screws. In 5.5 pcf foam material, the
construct failed at 137 N (mean) with secondary
3.5 mm locking screws vs. 94 N (mean) without
secondary 3.5 mm locking screws.

4 Synthes MultiLoc Proximal Humeral Nail Technique Guide
A
B
C
D
E
F
G
* Comparative testing conducted by Synthes with the MultiLoc Proximal Humeral
Nail construct implanted in polyurethane foam block material of multiple densities.
Testing compared the stability of the nail construct with and without secondary
3.5 mm locking screws assembled with the proximal lateral screws. Results
showed as much as a 45% increase in construct stability when the secondary
3.5 mm locking screws were assembled with the proximal lateral screws and the
construct was subjected to a static mediolateral bending force. Bench test
results do not necessarily reflect clinical performance.
Proximal locking: Levels A to D
The three lateral screws (greater tuberosity, levels A, B, and
D) must be used in any fracture situation, as they ensure the
basic stability of the construct.
Screw type:
– 4.5 mm Titanium MultiLoc Screws (gold)
The anterior screw (lessor tuberosity, level C) increases the
stability of the construct. It may be used in fractures with a
lesser tuberosity fragment if the fragment is large enough
to accommodate the screwhead. Do not insert a 3.5 mm
locking screw in this location.
Screw type:
– 4.5 mm Titanium MultiLoc Screws (gold)
Additional locking screws (greater tuberosity, levels A, B,
and D) may be inserted through the screwheads of the
lateral screws, to increase stability of the osteosynthesis.
These locking screws are aimed posteriorly where increased
bone density may be present. These additional screws may
be especially useful in osteopenic bone.*
Screw type (optional):
– 3.5 mm Titanium Locking Screws (green)
Ascending screw: Level E
The ascending screw supports the medial calcar region which
can be helpful in medially comminuted fractures.
Screw types:
– 4.0 mm Titanium Locking Screws (blue)
– 4.0 mm Titanium ASLS Screws (brown; optional)
Distal locking: Levels F and G
The two distal locking screws are located in different
planes to reduce implant toggling in the humeral canal,
compared to monoplanar locking.
Screw types:
– 4.0 mm Titanium Locking Screws (blue)
– 4.0 mm Titanium ASLS Screws (brown; optional)
Screw Configuration

1. M.E. Müller, M. Allgöwer, R. Schneider, and H. Willenegger.
Manual of Internal Fixation, 3rd Edition. Berlin: Springer-Verlag. 1991.
In 1958, the AO formulated four basic principles, which
have become the guidelines for internal fixation.1They are:
Anatomic reduction
Fracture reduction and fixation to restore anatomical
relationships.
Stable fixation
Stability by fixation or splintage, as the personality of the
fracture and the injury requires.
Preservation of blood supply
Preservation of the blood supply to soft tissue and bone
by careful handling.
Early, active mobilization
Early and safe active mobilization of the part and patient.
AO Principles
MultiLoc Proximal Humeral Nail Technique Guide Synthes 5

6 Synthes MultiLoc Proximal Humeral Nail Technique Guide
The MultiLoc Proximal Humeral Nail is indicated for fractures
of the proximal humerus, including:
– 2-part surgical neck fractures
– 3-part fractures
– 4-part fractures
Indications

MultiLoc Proximal Humeral Nail Technique Guide Synthes 7
Clinical Cases
Case 1: 2-part surgical neck fracture
78-year-old woman. Simple fall.
Treatment with:
– 8.0 mm MultiLoc nail
– 3 MultiLoc screws (levels A, B, and D)
– Standard distal locking
Preoperative, AP view Postoperative, AP view
Preoperative, scapular Y-view Postoperative lateral view
*Results from case studies are not predictive of results
in other cases. Results in other cases may vary.

Clinical Cases
Case 2: 3-part fracture
53-year-old woman. Simple fall, after 6
weeks of conservative treatment with
severe pain and impossible active
rehabilitation. Treatment with:
– 9.5 mm MultiLoc nail
– 3 MultiLoc screws (levels A, B, and D)
– 3.5 mm locking screw (screw-in-screw)
(level A)
– Ascending screw with ASLS
– Distal locking with ASLS
8 Synthes MultiLoc Proximal Humeral Nail Technique Guide
Preoperative, AP view Postoperative, AP view
Preoperative, scapular Y-view Postoperative lateral view

MultiLoc Proximal Humeral Nail Technique Guide Synthes 9
Case 3: Osteoporotic 4-part fracture
80-year-old woman. Simple fall. Treat-
ment with:
– 8.0 mm MultiLoc nail
– 3 MultiLoc screws (levels A, B, and D)
– 3.5 mm locking screw (screw-in-screw)
(level A)
– Suture fixation of lesser tuberosity
fragment
– Standard distal locking
Preoperative, AP view Preoperative, scapular Y-view
Preoperative, 3-D CT reconstruction Postoperative lateral view

Patient Positioning
1
Position patient
Position the patient in a beach chair position on a radiolu-
cent table. Support the shoulder with pads and place the
fractured arm on an adjustable side table or arm rest. Ensure
that the arm can be sufficiently reclined to expose the
humeral head anterior to the acromion.
Ensure that the C-arm placement allows visualization of the
entire humerus in two planes, e.g., at the head of the patient
or contralateral to the injured arm.
10 Synthes MultiLoc Proximal Humeral Nail Technique Guide
A modified supine position on a completely radiolucent table
can also be used. Position the C-arm to allow visualization of
the entire humerus in the AP and lateral planes. Place the
C-arm opposite the surgeon, perpendicular to the longitudinal
axis of the humeral shaft in the AP view.
Obtain a scapular “Y” lateral view by bringing the C-arm
through a 90° arc and projecting the beam directly at the
glenoid.

MultiLoc Proximal Humeral Nail Technique Guide Synthes 11
Approach
2
Approach
Perform an anterolateral approach. Begin the incision at the
anterolateral tip of the acromion and carry it distally over
the deltoid muscle. Split the deltoid muscle at the tendinous
intersection between the anterior and the middle third along
its fibers and retract it.
In complex fractures, a better view may be achieved by
partially detaching the deltoid muscle from the anterior
border of the acromion.
Caution: Do not extend the approach too far distally, to
prevent iatrogenic injury of the axillary nerve. The nerve may
be identified by gentle palpation or careful dissection. A stay
suture may be placed, to prevent further extension of the
incision. Deltoid muscle
Greater tuberosity
Supraspinatus muscle
Acromion
Infraspinatus muscle

Approach
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3
Reduce fracture
Instrument
292.16 1.6 mm Kirschner Wire, trocar point,
150 mm
Reduce the fracture via indirect reduction maneuvers, traction
sutures, an elevator, or Schanz screws or Kirschner wires
used as joysticks.
If necessary, use Kirschner wires to hold the fragments tem-
porarily in place during insertion of the implant. Ensure that
the Kirschner wires do not block insertion of the nail.
Check the reduction under imaging.

MultiLoc Proximal Humeral Nail Technique Guide Synthes 13
Opening the Humerus
1
Determine entry point
The ideal entry point is situated at the apex of the humeral
head, in line with the medullary canal in both AP and lateral
views. This point is located posterolateral to the biceps tendon
and medial to the sulcus between the greater tuberosity and
the humeral head.
Note: If the acromion inhibits access to the ideal entry point,
extend the shoulder to move the apex of the humeral head
in front of the acromion.
Entry point
Long biceps tendon
Lesser tuberosity
Greater tuberosity
Sulcus

2
Insert guide rod
Instruments
03.019.026 2.5 mm Guide Rod with Stop, trocar tip,
230 mm
393.105 Small Universal Chuck with T-Handle
Partially insert the guide rod at the appropriate insertion
point, using the small universal chuck.
Check the position of the guide rod in both AP and lateral
views.
Make a longitudinal incision of 1 to 2 cm through the
supraspinatus tendon along its fibers, at the position of the
guide rod. Use holding sutures and retractors to obtain
access to the operative field.
Advance the guide rod until its stop reaches the bone surface.
Remove the small universal chuck.
Continue with Step 3, Option A.
Caution: Do not damage the hypovascular zone of the
rotator cuff near its insertion on the humerus.
14 Synthes MultiLoc Proximal Humeral Nail Technique Guide
Alternative technique: Insert K-wire
Instrument
292.26 2.5 mm Kirschner Wire, trocar point, 285 mm
If the cannulated awl is preferred for opening the medullary
canal, insert a 2.5 mm Kirschner wire instead of the guide rod.
Continue with Step 3, Option B.
Opening the Humerus

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3
Open medullary canal
Option A: With hollow drill bit
Instruments
03.019.003 10.0 mm Hollow Drill Bit, for MultiLoc Humeral
Nailing System
or
03.019.004 11.5 mm Hollow Drill Bit, for 9.5 mm MultiLoc
Proximal Humeral Nail
03.019.027 Protection Sleeve, for 03.019.003 and
03.019.004
Pass the hollow drill bit through the protection sleeve and
over the guide rod to the bone. Drill to the depth of the
medullary canal.
Remove the hollow drill bit, protection sleeve, and guide rod.
Note: Use the 11.5 mm hollow drill bit marked with a gold
band for the 9.5 mm MultiLoc Proximal Humeral Nail. For all
other nails, use the 10.0 mm hollow drill bit.
Nail dia. Hollow drill bit
Nail (mm) (mm)
MultiLoc Proximal Humeral Nail 8.0 10.0
MultiLoc Proximal Humeral Nail 9.5 11.5 (gold)
Option B: With awl
Instrument
03.010.039 10.0 mm Cannulated Awl
Pass the cannulated awl over the Kirschner wire to the bone.
Use a twisting motion to advance the awl to the depth of
the medullary canal.
Remove the awl and the Kirschner wire.
Caution: When using the cannulated awl, take care to not
displace the fracture, especially in complex fracture cases.

Nail Insertion
1
Assemble insertion instruments
Instruments
03.019.006 Insertion Handle for MultiLoc Proximal Humeral
Nail
03.019.007 Connecting Screw, cannulated, for MultiLoc
Humeral Nail
321.16 Combination Wrench, 11.0 mm width across
flats
Orient the insertion handle laterally and match the geometry
of the insertion handle to the nail. Pass the connecting screw
through the insertion handle and into the nail. Secure the
assembly with the combination wrench.
Note: The anatomic design of the MultiLoc Proximal
Humeral Nail requires right and left versions. Nails are labeled
“RIGHT” or “LEFT”.
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2
Insert nail
Insert and advance the nail into the medullary canal using
twisting motions. Orient the insertion handle laterally.
Monitor the nail passage across the fracture and control it in
two planes to avoid misalignment.
In case of a metaphyseal fracture, advance the nail to the
fracture site, reduce the fracture and continue into the
diaphysis.
Check the nail position in AP and lateral views.
Caution: The proximal end of the nail must be inserted below
the humeral head surface to avoid impingement.
Warning: Do not use a hammer, as this may increase the
risk of iatrogenic fractures.
Notes:
– If nail insertion is difficult, choose a smaller diameter nail
or ream the intramedullary canal to a larger diameter.
– Pressure against the elbow when advancing the nail
prevents distraction and potential healing problems.
MultiLoc Proximal Humeral Nail Technique Guide Synthes 17

Nail Positioning
1
Assemble lateral aiming arm
Instruments
03.019.008 Aiming Arm, lateral, for MultiLoc Proximal
Humeral Nail
03.019.030 Aiming Arm Knob
Insert the knob into the aiming arm, ensuring that the aim-
ing arm is oriented correctly. Attach the aiming arm to the
insertion handle and tighten the knob.
Note: Ensure the aiming arm shows “RIGHT” if used for the
right humerus and “LEFT” if used for the left humerus.
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Optional technique: Assemble anterior aiming arm for
anterior screw (level C) or ascending screw (level E)
Instruments
03.019.009 Aiming Arm, anterior, for MultiLoc Proximal
Humeral Nail
03.019.031 Aiming Arm Knob
If the anterior screw (lesser tuberosity) or the ascending
screw will be used, connect the anterior aiming arm to the
insertion handle and tighten the knob.