Zimmer MotionLoc Screw For The Periarticular Locking Plate System Surgical Technique, 97 2347 035 00 Technique

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Zimmer®

MotionLoc® Screw

for the Periarticular

Locking Plate

System

Surgical Technique

Zimmer® MotionLoc® Screw for the Periarticular Locking Plate System

Background

A plating construct needs to be strong enough to support the damaged bone while the fracture heals. However, too

much stiffness forces the body to heal through osteonal or primary/direct healing. Primary healing requires nearly

perfect anatomic reduction and rigid compression for absolute stability which has proven to be a very complex and

unforgiving procedure.1 In animal studies, Far Cortical Locking Technology provides controlled axial flexibility to promote

fracture healing through callus formation, or secondary healing, by stressing the fracture with micromotion at the

fracture site.2 The idea of Far Cortical Locking Technology motivated Zimmer to create Zimmer® MotionLoc® Screws for

NCB® Plates and now, a stainless steel version for use with Zimmer Periarticular Locking Plates.

ZIMMER MotionLoc SCREW DESIGN

MotionLoc Screws look different than most cortical screws. The picture below outlines the different design aspects.

A. B. E.

Locking Motion Cortical

Threads Control Collar Threads

C.

Reverse Cutting

Threads

D.

Expanded

Core Section

Fig. 1

2

3

Zimmer® MotionLoc® Screw for the Periarticular Locking Plate System Zimmer® MotionLoc® Screw for the Periarticular Locking Plate System

A. Locking Threads

This is the portion of the screw that locks into the

plate. The head of the screw is threaded to match the

threaded holes in the plates.

B. Motion Control Collar

This is the portion of the MotionLoc Screw that makes

it unique. The diameter of this portion has been

reduced in comparison to the distal end of the screw.

This allows the screw within the drilled hole to flex

through elastic deformation without permanently

deforming the screw. This is called the working length

of the screw because this is the area that flexes a

controlled amount to create the desired micromotion

at the fracture site (Fig. 2).

NOTE: Working Length

Increased flexibility of the screw is directly

proportional to the length of the screw. Mechanically,

MotionLoc Screws behave in a manner similar to a

cantilever beam. As the length of the beam/screw

increases so does the beam/screw flexibility.

It is important to maximize the working length of the

screw, so centering the screw in the bone is key. The

figure below shows how the screw is affected when

placed off-center (Fig. 4).

Fig. 2

Motion Control Collar

Fig. 3

To maximize working length, center screw in bone.

High

Load

Near

Cortex

Far

Cortex

Locked

Plate

Locked

Plate

Fig. 4

As the screw length increases, the working length increases,

and so does the screw flexibility.

Screw

Length

46

44

42

Working Length Cortical Length

Cortex

Zimmer® MotionLoc® Screw for the Periarticular Locking Plate System

4

C. Reverse Cutting Threads

The reverse cutting threads on the working length of

the screw ease screw removal. The reverse cutting

threads are designed to engage with the near cortex

before the threads on the tip of the screw disengage

with the far cortex, so the screw can be backed out

(Fig. 5).

D. Expanded Core Section

The expanded core section of the screw is a little larger

than the outer diameter of the motion control collar.

As the screw advances through the drilled hole upon

insertion, it leaves a bigger motion envelope behind it

for the working length of the screw (Fig. 6).

E. Cortical Threads

This is the portion that fixes into the cortical bone

for hold. It has the same thread form as a standard

cortical screw and is inserted using a standard surgical

procedure. Since MotionLoc screws are only fixed in the

far cortex, radiographs must be inspected to confirm

the screw tip has completely engaged that cortex.

The MotionLoc Screws are intended for use in the

diaphyseal segment of a fracture where screw purchase

in the far cortex opposite the plate can be obtained.

They are not for use in the metaphysis or epiphysis

of the bone. Fig. 6

Expanded Core section passing through the near cortex.

Fig. 5

Reverse cutting threads

5

Zimmer® MotionLoc® Screw for the Periarticular Locking Plate System Zimmer® MotionLoc® Screw for the Periarticular Locking Plate System

Reducing Stiffness of Locked

Plating Constructs

MotionLoc Screws reduce the locked plating construct

stiffness by more than 58% while retaining construct

strength.3 The stiffness reduction through the screws

creates nearly parallel micromotion at the fracture site.

Indications for Use

MotionLoc Screws, when used with the Periarticular

Locking Plate System, are indicated for temporary

internal fixation and stabilization of osteotomies and

fractures of long bones, including:

• Comminuted fractures

• Supracondylar fractures

• Intra-articular and extra-articular condylar fractures

• Fractures in osteopenic bone

• Nonunions

• Malunions

Contraindications

Contraindications include:

• All concomitant diseases that may impair the fixation

of the implant and/or the success of the intervention.

• Acute or chronic, local or systemic infections.

• Severe muscular, neural, or vascular diseases that

endanger the extremities involved.

• Lack of bone substance or bone quality, which makes

stable seating of the screws impossible or results

in an unstable screw/plate construct.

• Allergy to the implanted material.

Preoperative Preparation

After assessing the fracture radiographically

and preparing a preoperative plan, position the

patient on the appropriate table. Ensure that the

fluoroscope can be positioned to visualize the

appropriate bone in both the lateral and anterior/

posterior views. For specific preoperative positioning,

refer to the surgical technique for the appropriate

Zimmer Periarticular Locking Plate being used.

Plate Selection

Two factors to consider when choosing plate length:

(1) Location of the fracture and (2) the number and

distribution of the screws around the fracture site.

W WARNING: When considering the number and

distribution of screws, remember that a minimum

of 3 MotionLoc screws must be placed on the

diaphyseal side of the fracture to use the product.

MotionLoc screws should be placed (1) distal to

the fracture in proximal humerus and proximal tibia

fractures; and (2) proximal to the fracture for distal

femur and distal tibial fractures. The remainder

of the Periarticular Locking Plate is secured as

described in the Periarticular Locking Plate package

insert and corresponding surgical technique

(Proximal Tibial Plates, Distal Tibial Plates, Proximal

Humeral Plates, and Distal Femoral Plates).

With the Zimmer Periarticular Locking Plate System, the

threaded-round holes in the shaft are the locking holes.

MotionLoc Screws must lock into the plate and must be

inserted into the threaded-round shaft holes (Fig. 7).

MotionLoc screws may be grouped more tightly around

the fracture than with standard locking screws as

they reduce the stiffness and translate micromotion

into the fracture site. This allows them to be placed in

consecutive locking holes.

MotionLoc Screw placement

Fig. 7

3 MotionLoc screws

6Zimmer® MotionLoc® Screw for the Periarticular Locking Plate System

Plate Placement and Fracture Reduction

Center the plate on the bone as much as possible.

MotionLoc screws function best when the working length

is maximized across the widest portion of the bone

(Fig. 8).

Provisional fixation with k-wires or drill bits may be used

to more accurately place the plate.

Fix the metaphyseal and epiphyseal segments of the

fracture as described in the surgical techniques for the

corresponding plate used.

W WARNING: Standard Periarticular Locking screws

or cortical screws should NOT be used in the same

fracture segment as the MotionLoc Screws as this

may lead to a stress riser and potential failure.

Compression technique should only be used in the

metaphysis.

4.5mm Zimmer MotionLoc Screw Technique

To insert the 4.5mm Zimmer MotionLoc Screws, thread

the 3.7mm Standard Cannula (Blue Ring) into the

desired locking hole.

Use the 3.7mm Standard Drill through the cannula to

drill a pilot hole. Use the fluoroscope to confirm the drill

position in both the A/P and lateral planes. Remove the

cannula.

If drilling in hard cortical bone, tap the far cortex with the

4.5mm Locking Screw Tap.

Screw Length Measurement

MotionLoc screws should fully engage the far cortex (Fig.

9). Use the 4.5mm Locking Screw Depth Gauge to obtain

a screw length reading. Add 2mm to that reading to

select the appropriate MotionLoc screw length.

Screw Insertion

Select the appropriate MotionLoc Screw from the

MotionLoc Screw Caddy for Zimmer Periarticular Locking

Plate System. Insert the screw using the 5.0mm Hex

Screwdriver until it has threaded into the locking hole of

the Periarticular Locking Plate.

Fig. 8

Center the MotionLoc Screws

Fig. 9

Screw Length Measurement

2mm

2mm

7

Zimmer® MotionLoc® Screw for the Periarticular Locking Plate System Zimmer® MotionLoc® Screw for the Periarticular Locking Plate System

N NOTE: To ensure that the MotionLoc Screw finds

the drilled hole in the far cortex, it is important to

align the screw in the direction of the drilled hole

while inserting the screw. Use alignment of the

depth gauge prior to its removal to determine proper

orientation of screw prior to placement.

Follow the same procedure to insert a MINIMUM of three

(3) MotionLoc Screws into the shaft of the bone. Ensure

that all screws are securely tightened.

3.5mm MotionLoc Screw Technique

To insert the 3.5mm MotionLoc Screws, thread the

2.7mm Standard Cannula (Black Ring) into the desired

locking hole.

Use the 2.7mm Standard Drill through the cannula to

drill a pilot hole. Use the fluoroscope to confirm the drill

position in both the A/P and lateral planes. Remove the

cannula.

If drilling in hard cortical bone, tap the far cortex with the

3.5mm Locking Screw Tap.

Screw Length Measurement

Use the 3.5mm Locking Screw Depth Gauge to obtain a

screw length reading. Add 2mm to that reading to select

the appropriate screw length. MotionLoc screws should

fully engage the far cortex.

Screw Insertion

Select the appropriate MotionLoc Screw from the

MotionLoc Screw Caddy for Zimmer Periarticular Locking

Plate System. Insert the screw using the Small Hex

Screwdriver until it has threaded into the locking hole of

the Periarticular Locking Plate.

Follow the same procedure to insert a MINIMUM of three

(3) MotionLoc Screws into the shaft of the bone. Ensure

that all screws are securely tightened.

Fig. 10

Screw removal

Implant Removal

MotionLoc screws have been designed to aid in the

removal process. A portion of the screw has reverse

cutting threads to engage in the near cortex bone as the

cortical threads disengage from the far cortex of bone

(Fig. 10).

To remove the Zimmer Periarticular Locking Plate, back

off all bone screws. This prevents rotation of the plate

when removing the last screw. Then completely remove

all screws with the screwdriver, ensuring that the tip of

the screwdriver is completely seated in the hex drive of

the screw. Failure to do so could damage the hex drive

and complicate the extraction of the implant.

97-2347-035-00 Rev. 2 MC 120978 1-29-15 Printed in USA ©2015 Zimmer, Inc.

Contact your Zimmer representative or visit us at www.zimmer.com

The CE mark is valid only if it is also printed on the product label.

References

1. Skirving AP, Day R, Macdonald W, McLaren R: Carbon fiber reinforced plastic (CFRP) plates versus stainless steel dynamic compression

plates in the treatment of fractures of the tibiae in dogs. Clin Orthop Relat Res 1987; 224:117-124.

2. Bottlang M, et al. Far cortical locking can improve healing of fractures stabilized with locking plates.

J Bone Joint Surg (A), 92:7,2010.

3. Data on file at Zimmer. (ZRR 2671-13 & ZRR 2674-13)

DISCLAIMER:

This documentation is intended exclusively for physicians and is not intended for laypersons. Information on the products and

procedures contained in this document is of a general nature and does not represent and does not constitute medical advice or

recommendations. Because this information does not purport to constitute any diagnostic or therapeutic statement with regard

to any individual medical case, each patient must be examined and advised individually, and this document does not replace

the need for such examination and/or advise in whole or in part.

Please refer to the package inserts for important product information, including, but not limited to, indications,

contraindications, warnings, precautions, and adverse effects.