LC-DCP System. Dynamic compressionplates with limited bone contact.

Technical Features

Application

Clinical Cases

2

LC-DCP� System

Plate Hole Geometry

Technical Improvements in the LC-DCP�

(LC-DCP�: Limited Contact Dynamic Compression Plate)

The symmetrical shape of the plate holes enables compressionto be achieved in both directions.

The ability to incline screws at up to 40° to the perpendicularpermits an even wider range of applications.

The hole spacing in the LC-DCP� is regular. Plate positioning isthus not restricted by the presence of a mid-section. This is ofparticular advantage in comminuted or segmental fractures.

A double fracture, spanned by the LC-DCP� and lag screwsthrough the plate.

No Mid Section

New plate design renders the LC-DCP� uniformly stiff. This fa-cilitates contouring to the bone and reduces stress concentra-tions.

Screw-head fit is maintained during bending as the plate holesdeform minimally during plate shaping.

Uniform Implant Stiffness

LC-DCP�

Standard

40º 40º

Standard LC-DCP�

3

SYNTHES �

Plate Contouring

Treating juxta-articular fractures (distal tibia, tibial plateau,distal femur, distal humerus, radius etc.), good contouring ofthe plate to the shape of the bone is very important. Only thuscan satisfactory reduction and adequate stability be obtained.

The LC-DCP� plates are made of AO Pure Titanium, featuringoptimum biocompatibility. Pure Titanium has mechanical pro-perties different from stainless steel. Due to its lower modulusof elasticity, Titanium is more springy. Therefore Titaniumplates should be somewhat over-bent to obtain the desiredshape.

The design of the LC-DCP� plates ensures uniform rigidity,hence a continuous curvature after bending. The plates shouldnot be bent beyond the necessary extent, however. “To-and-fro” bending should particularily be avoided.

Sharp indentations on the plate surface, especially around theplate holes, may impair resistance to fatigue and should beavoided.

4

LC-DCP� System

Shaft Screw Used as a Lag Screw toAchieve Full Compression

The shaft screw achieves optimum compres-sion.

The shaft screw (shown on the right) slides freely through thegliding hole. Optimum compression can thus be achieved.

Using a fully-threaded cortex screw, only50% of the possible compression areachieved.

In order to achieve optimum compression, the lag screw mustbe able to glide freely within the gliding hole. If a cortex screwis used as a lag screw, there is a tendency for the screw-threadto be pressed into the cortex on the compressed fracture sideof the screw hole as the screw is tightened. The screw canthen no longer glide freely within the gliding hole and thecompression effect is impaired. Previously

New

5

SYNTHES �

Use of a Lag Screw through the PlateAchieves Additional Stability

In certain circumstances, the use of a plate for fracture com-pression may be sufficient. In many fractures, however, it isadvantageous to insert a lag screw through the plate to in-crease fracture stability.

A lag screw is used to achieve additional stability and inter-fragmentary compression in the far cortex.

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If fracture gaps remain, the plate is subjected to high bendingstresses.

Reduction in implant stress by using a lag screw through theplate*.

* Source: Klaue K. et al., 1985 Die Entlastung der Osteosyntheseplatte durch interfragmentäre Plattenzugschraube.

2000

1000

0

–1000

0 20 40

Plate stress without a lag screw

Days postoperative

2000

1000

0

–1000

0 20 40

Plate stress with a supplementary lag screw

Days postoperative

6

LC-DCP� System

1 0

green yellow

LC-DCP� Drill Guide 4.5• neutral (green) and compression

(yellow) position• for narrow and broad LC-DCP� 4.5

The instruments for LC-DCP� implantation are virtually the same as those used for the DCP�. The new shapeof the holes, however, requires different drill guides:

Neutral and Compression LC-DCP� Drill Guides

yellowgreen

green yellow

1 2

3

= symbol for a fracture line

LC-DCP� Drill Guide 3.5• neutral (green) and compression

(yellow) position• for LC-DCP� 3.5

The new plate hole is symmetrically sha-ped. It now possesses one compressionpoint and one neutral point on both si-des. The two drill guides bear an arrowenabling correct positioning of thescrew.

1 Neutral positionThe arrow on the green drill guidemust point towards the fracture toenable a screw to be placed in neu-tral position. Compression cannotbe achieved with the green drillguide.

2 CompressionThe yellow drill guide enables com-pression to be achieved. Important:the arrow must always point to-wards the fracture.

3 Buttress positionUse the green drill guide. A buttresseffect is achieved when the arrowpoints away from the fracture.

Use of the LC-DCP�

compression positionarrow points towards the fracture

neutral postitionarrow points towards the fracture

green

buttress positionarrow points away from the

fracture

7

SYNTHES �

Universal Drill Guide 4.5/3.2

1 Predrilling in neutral positionDepress drill guide (upper part of in-ner sleeve projects). Position in platehole remote from the fracture.

2 Predrilling in compression positi-onDo not depress drill guide (upperpart is flush). Position in plate holeremote from the fracture.

S Predrilling in inclined positionFor lag screws through the plate.Depress drill guide (upper part pro-jects).

3 Predrilling in buttress positionDepress drill guide as shown for neu-tral position (upper part projects).Position in plate hole adjacent tothe fracture.

Universal Drill Guide 3.5

The Universal Drill Guide is an alternative to the green/yellow drill guide for LC-DCP� and DCP� plates. Dueto its spring mechanism, all types of applications are possible: neutral position, compression position,buttress position and especially the positioning of inclined lag screws through the plate.

Universal Drill Guide 4.5/3.2 1)

S

1) Patent pending

compression positionneutral position inclined position

1 2

3

buttress position

8

LC-DCP� System

2 • Seat the universal drill guide against the hole side remotefrom the fracture.

• Do not depress drill guide.

Screw is set in compression position. A compression path of1 mm will be achieved upon screw tightening.

1 • Seat the universal drill guide against the hole side remotefrom the fracture.

• Depress drill guide (upper part of inner sleeve projects).

Screw is set in neutral position. No shift between plate andbone occurs.

Application of theUniversal Drill Guide 4.5/3.2

5

2

1 4

3

Technical Description

1 Outer sleeve of the universal drill guide 4.5/3.22 Hemispheric underside, corresponding to screw-

head geometry3 Inner sleeve, internal diameter 3.2 mm, external

diameter 4.5 mm. Equipped with a spring whichmakes the drill guide suitable for all screw positi-ons.

4 Handle5 Drill guide/tissue-protecting sleeve for drill bit

and tap 4.5 mm dia. for cortex screws 4.5 mm

The drill guide may be dismantled for cleaningpurposes.

Unlike the DCP�, the neutral position of the LC-DCP� hole is not in the middle of the plate hole.

21

Drilling in neutral position (1) Drilling in compression position (2)

9

SYNTHES �

Tightening of the screw in this position, where the head of thescrew is in contact with the upper edge of the plate hole, sub-jects the screw to considerable bending stresses in addition tothe normal axial stresses. This may possibly cause screw-headbreakage.

The shape of the underside of the neutral and compressiondrill guide fits the hole only in a more or less vertical position.Correct positioning of the screw is ensured.Optimum positioning is not guaranteed in the inclined posi-tion. There is a danger of the screw-head coming into contactwith the upper edge of the hole when being inserted (see figu-re on the right).

S

The hemispheric underside of the universal drill guide 4.5/3.2corresponds to the shape of the screw-head. Place the drillguide in the hole adjacent to the fracture, depress, and set thedesired drill angle.

Use of the universal drill guide 4.5/3.2 allows ideal positioningof the head of the inclined lag screw.

Tightening of the screw subsequent to predrilling, drilling ofthe gliding hole, and tapping. This does not subject the screwhead to additional bending stresses.

Drilling in inclined position:Neutral and compression drill guide not recommended

Drilling in inclined position (S)

correct

incorrect

10

LC-DCP� System

1 0

Compression Plate: Simple Fracture

Clinical Cases

The LC-DCP� has regularly spaced holes along the whole of itslength, thus the plate position is not dictated by the positionof the mid section. When choosing the length of the plate,ensure that enough holes are over both fragments, and that alag screw can be inserted if necessary.Illustrations show the procedure with the neutral and com-pression drill guide.

Drill through both cortices into the opposite fragment with3.2 mm dia. drill bit and yellow drill guide in compression po-sition (arrow points towards the fracture).

In order to achieve axial compression of the fracture, the screwmust shove the bone laterally beneath the plate. The screw isthus subjected to lateral bending forces as well as to axialforces. For this purpose a stronger 4.5 mm shaft screw is re-commended. As the shaft has a diameter of 4.5 mm, the nearcortex has to be drilled to a diameter of 4.5 mm. (Use thetissue protecting sleeve.)

Important: Whenever possible, the screws for axial compres-sion should be placed in such a way that the apex of the frag-ment is drawn into the open wedge between plate and bone.This greatly reduces the risk of the fragment slipping.

Drill the first hole adjacent to the fracture using a 3.2 mm dia.drill bit with the drill guide in neutral position (green drillguide, arrow pointing towards the fracture). Determine screwlength, tap the thread, and insert the screw. The screwdrivershould be turned around the same axis as the screw axis(i.e. screw and screwdriver in straight line). Lever stresses,which could otherwise lead to screw breakage, are thusavoided.

green

yellow 3.2

4.5

11

SYNTHES �

Widen the hole in the near cortex with the 4.5 mm dia. drillbit. Push tissue protecting sleeve upwards, insert the drill bitinto the hole, then slide the tissue protecting sleeve down untilit touches the plate. When drilling, care should be taken thatthe course of the glide hole follows exactly that of the 3.2 mmdrill hole.

Use of a shaft screw as a lag screw ensures efficient gliding ofthe screw shaft in the gliding hole resulting in a considerablyhigher tension effect*. This achieves compression in the farcortex, too.

Insertion of a lag screw. This mostly brings about better com-pression in the near than in the far cortex.

* see pages 4-5

To increase stability in the far cortex, and decrease plate wear,an interfragmentary lag screw is inserted*. Preparing the lagscrew: Drill through both cortices with universal drill guide4.5/3.2 depressed and 3.2 mm dia. drill bit. The hemisphericunderside of the universal drill guide 4.5/3.2 permits idealpositioning of the screw-head.

The remaining screw holes get filled by screws placed in theneutral position apart from the hole directly above the frac-ture.

Completion of fracture treatment.

S

4.5

3.2

12

LC-DCP� System

Fractures should be treated consecutively.

Compression Plate: Multifragmentary Fracture

3.2

3.2

A screw is then inserted into the middle fragment. Prepare thescrew hole with a 3.2 mm dia. drill bit and the universal drillguide 4.5/3.2 depressed for neutral position, upper part ofinner sleeve projecting (possibly choose a short screw).

A screw is inserted into the hole. Use of a shaft screw is recom-mended. Mostly higher compression is achieved in the platedcortex than in the part distant from the plate.

For treatment of the first fracture, follow the previously de-scribed example step by step.

Course of treatment of the second fracture using the univer-sal drill guide 4.5/3.2 to be carried out as follows.

Drill a 3.2 mm dia. hole into the third fragment using theuniversal drill guide 4.5/3.2 in compression position. Thedrill guide is seated at the side of the hole remote from thefracture without depressing the drill guide (upper part isflush).A 4.5 mm dia. gliding hole is then drilled, the screw lengthmeasured, and the thread tapped.

13

SYNTHES �

Prepare lag screw seating with the universal drill guide 4.5/3.2and the drill bit 3.2 mm dia. Positioning of the universal drillguide 4.5/3.2 adjacent to the fracture, depress drill guide, setdrilling angle, drill (if there be the risk of the drill bit collidingwith the screw in the vicinity, the drill bit has to be inclined).

Now the gliding hole is drilled. Widen the near cortex usingthe drill bit 4.5 mm dia. and the tissue protecting sleeve, too(keep in direction). Measure the screw length and tap thethread.

By insertion of a shaft screw as lag screw, additional stability isachieved. Lag and compression screw possibly to be tightenedalternately.

The remaining screw holes are filled with neutrally placedscrews.

S

3.2

4.5

Place the screw.

14

LC-DCP� System

All the screw holes in the buttress re-gion are prepared with the universaldrill guide 4.5/3.2 or the green (neutralposition) drill guide of the LC-DCP� drillguide. Here, the arrow of the drillguide points away from the frac-ture. The proximally positioned cancel-lous bone screws and cortex screws actas lag screws. The thread grips only inthe opposite fragment, so that there iscompression between the fragments.Use of the green drill guide with the ar-row “away from the fracture” preventsthe tibial plateau fragment and theplate from slipping. In this situation, thescrew-heads are buttressed by the holeedge adjacent to the fracture.

Buttress Plate

A shear fracture of the lateral part ofthe tibial head combined with a shortoblique fracture. First the distal obliquefracture is treated as in the previouslyillustrated examples.

green

= symbol for a fracture line.

15

SYNTHES �

Neutralization Plate (Protecting Plate)

green

Adapt spiral fracture with two separatelag screws.

Position plate to bridge fracture usingLC-DCP� drill guide or universal drillguide 4.5/3.2.LC-DCP� drill guide (green): arrowpoints towards the fracture.

Universal drill guide: seat at hole edgeremote from the fracture, depress outersleeve, upper part projects for neutralposition.

To complete fracture treatment, deter-mine screw lengths and insert screwsafter having tapped the threads.

WARNINGThis description is not sufficient foran immediate application of the in-strumentation. An instruction by anexperienced surgeon in handlingthis instrumentation is highly re-commended.

Subject to alterations.

16

LC-DCP� System

Clinical Indications

Indications for the LC-DCP� are the same as those for the DCP�.

Fractures before treatment

34 weeks postoperativelyimmediately postoperatively

This second-degree compound fracture of the forearm of apolytraumatised patient was treated postprimarily. The LC-DCP� 3.5 and DCP� 3.5 respectively stabilised the fractures. Atthe same time, autologous bone grafting with cancellousbone was performed on the bone defect in the radius. The X-rays showing healing of the fractures were taken eight mont-hs after internal fixation.

17

SYNTHES �

Fractures before treatment

16 weeks postoperatively

This lower leg torsion fracture was fixed with a narrow LC-DCP� 4.5 with 7 holes. The shaft screw was used as a plate lagscrew.

18

LC-DCP� System

Fractures before treatment

48 weeks postoperatively

In the presence of epiphyseal cartilage, this femoral fracturecaused by a skiing accident was treated using a broad LC-DCP� 4.5. The function of the 12-hole plate was to bridge thecomminuted zone. The final X-rays were taken shortly beforeplate removal.

immediately postoperatively

19

SYNTHES �

This 93 year old female patient fractured her femoral shaftby slipping on a patch of ice. Primary internal fixation of thewedge-shaped torsion fracture was carried out with a narrowLC-DCP� 4.5 with 12 holes. The lag screw inserted obliquelythrough the plate acts as a shaft screw.

Fresh fractures immediately postoperatively

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