Principles of Plating

Submitted by Submitted by

A.PRAKASHA.PRAKASH

BVN 03038BVN 03038

FINALBVSCFINALBVSC

Based on Based on

1.1. Presence of communicating external Presence of communicating external wound.(open & closed)wound.(open & closed)

2.2. Extent of damage( complete , Extent of damage( complete , greenstick,fissure fracture)greenstick,fissure fracture)

3.3. Direction and location of fracture Direction and location of fracture (transverse, oblique, spiral, (transverse, oblique, spiral, communited, multiple, impacted, communited, multiple, impacted, avulsion, unicondylar, bicondylar avulsion, unicondylar, bicondylar fracture.fracture.

4.4. Stable and unstable fracture.Stable and unstable fracture.

Tension

Bending

Rotation

Compression

Fracture Forces

Shear

SHEARTensile and compressive forces act perpendicular or normal to a structure's surface

Principles of Internal Principles of Internal FixationFixation

The Goals of fracture repair areThe Goals of fracture repair are

Promote/enhance/allow bone healingPromote/enhance/allow bone healing Atraumatic techniqueAtraumatic technique Good reduction/alignmentGood reduction/alignment Stable fixationStable fixation Early return to full function****** Early return to full function******


Open reduction Open reduction Surgical exposure of the fracture site for fixationSurgical exposure of the fracture site for fixation Fixation is usually internalFixation is usually internal

Closed reductionClosed reduction Fracture site is not openedFracture site is not opened External fixation (casts, splints, etc.) External fixation (casts, splints, etc.) Becoming more popular with advanced imagingBecoming more popular with advanced imaging


Advantages of internal fixationAdvantages of internal fixation Rigid fixation usuallyRigid fixation usually Allows weight bearing during healingAllows weight bearing during healing

Health of the limb and joints Health of the limb and joints Increases the circulationIncreases the circulation Promotes healingPromotes healing

Hidden implantsHidden implants No extensive careNo extensive care


Disadvantages of internal fixationDisadvantages of internal fixation

InvasiveInvasive Potential to slow healing Potential to slow healing InfectionInfection Longer procedureLonger procedure Higher cost Higher cost


Factors affecting fracture repairFactors affecting fracture repair Type of fracture (simple/comminuted)Type of fracture (simple/comminuted) Anatomical area Anatomical area

ArticularArticular Which limbWhich limb Where on the boneWhere on the bone

Extent of soft-tissue damageExtent of soft-tissue damage Duration of fractureDuration of fracture


Factures affecting fracture repairFactures affecting fracture repair

Animal’s age, weight and temperamentAnimal’s age, weight and temperament Owner’s finances Owner’s finances Available aftercareAvailable aftercare Equipment available Equipment available Surgeon’s experienceSurgeon’s experience

Plates come in a wide variety of shapes and

sizes

ScrewsScrews Cortical ScrewsCortical Screws

More threads, low pitch, More threads, low pitch, less thread depthless thread depth

Only fully threadedOnly fully threaded Used for cortical boneUsed for cortical bone

Cancellous ScrewsCancellous Screws Less threads, steep Less threads, steep

pitch, wide threadpitch, wide thread Fully and partially Fully and partially

threadedthreaded Used in soft boneUsed in soft bone

ScrewsScrews

Used to secure bone plates to boneUsed to secure bone plates to bone Used as primary means of fracture Used as primary means of fracture

repair repair Used to hold fracture fragments in Used to hold fracture fragments in

place place Used to compress fracture fragmentsUsed to compress fracture fragments Used to form prosthetic ligamentsUsed to form prosthetic ligaments

ScrewsScrews

Lag principleLag principle

Used to compress fracture fragmentsUsed to compress fracture fragments Used to hold plates on bone Used to hold plates on bone Threads only engage far cortexThreads only engage far cortex

(Or they don’t engage the plate)(Or they don’t engage the plate) Can be accomplished with Can be accomplished with

Partially threaded screw Partially threaded screw Over drilling near cortexOver drilling near cortex Articular fracturesArticular fractures Sacroiliac luxationsSacroiliac luxations

Bone PlatesBone Plates

Bone plates and screws offer Bone plates and screws offer versatile method of fracture of versatile method of fracture of stabilization.stabilization.

Necessary for many fractures.Necessary for many fractures. Requires specialized equipment and Requires specialized equipment and

training.training. Not readily available in many Not readily available in many

practices.practices. More expensive than pinning.More expensive than pinning.

PlatesPlates Plate placementPlate placement

Reconstruct the boneReconstruct the bone Contour plate Contour plate Drill, measure, and tap screw holes (one Drill, measure, and tap screw holes (one

by one)by one) Apply screws from the fracture site out, Apply screws from the fracture site out,

alternating bone fragmentsalternating bone fragments Engage at least six cortices per a major Engage at least six cortices per a major

bone fragmentbone fragment More for comminuted fractures if possibleMore for comminuted fractures if possible

Bone PlatesBone Plates

CounteractCounteract

TensionTension CompressionCompression ShearShear Bending Bending Rotational forcesRotational forces

Bone plates should be placed on the Bone plates should be placed on the

tension side of the bonetension side of the bone

Tension side of the boneTension side of the bone

FemurFemur CraniolateralCraniolateral

Tibia*Tibia* CraniolateralCraniolateral

HumerusHumerus CraniolateralCraniolateral

RadiusRadius CranialCranial

Ulna*Ulna* CaudalCaudal

Mandible*Mandible* dorsaldorsal

Some are not plated on the tension side due to impracticality and added difficulty

CompressionCompression

Mechanical compression Mechanical compression added to the fracture added to the fracture site.site.

The weight-bearing load The weight-bearing load is shared by both the is shared by both the plate and the bone.plate and the bone.

Primary bone healing Primary bone healing usually results.usually results.

Plate is applied Plate is applied eccentrically.eccentrically.

NeutralizationNeutralization Plate protects primary Plate protects primary

repair from weight-bearing repair from weight-bearing forcesforces

The weight-bearing load is The weight-bearing load is shared by both the plate shared by both the plate and the boneand the bone

Stabilize with series of lag Stabilize with series of lag screws and cerclege wires.screws and cerclege wires.

Numer of cortices is allowed Numer of cortices is allowed is six.is six.

ButtressButtress

Spans a gap to prevent Spans a gap to prevent collapse of a fracture collapse of a fracture

AllAll of the weight-bearing of the weight-bearing forces are transmitted forces are transmitted through the platethrough the plate

Minimum of cortices Minimum of cortices applied is 8.applied is 8.

For optimal strength use For optimal strength use broad plate and stacked broad plate and stacked vcp plates..vcp plates..

PlatesPlates

Dynamic compression platesDynamic compression plates

Allows compression of major bone Allows compression of major bone fragmentsfragments

External compressionExternal compression

Screws must be Screws must be LOADEDLOADED in order to get in order to get compressioncompression(eccentric placement in screw hole)(eccentric placement in screw hole)

Plate can function in compression, Plate can function in compression, neutralization, and as a buttress plate neutralization, and as a buttress plate depending on how the screws are applieddepending on how the screws are applied

1)1) Load Drill Guide:Load Drill Guide: Provides 1 mm Provides 1 mm compression, screws are placed eccentricallycompression, screws are placed eccentrically

2) 2) Neutral Drill GuideNeutral Drill Guide:: Places the drill hole Places the drill hole centrally, thus little displacement is provided.centrally, thus little displacement is provided.

Removing ImplantsRemoving Implants

In general, it is recommended that In general, it is recommended that all orthopedic implants be removed all orthopedic implants be removed

In practice, however, we rarely In practice, however, we rarely remove orthopedic implantsremove orthopedic implants


Why don’t we remove themWhy don’t we remove them

CostCost Post-op confinement requiredPost-op confinement required Traumatic surgeryTraumatic surgery Anesthesia riskAnesthesia risk Potential for refracturePotential for refracture


When to recommend removalWhen to recommend removal

Interferes with function Interferes with function Loosening or breakage Loosening or breakage InfectionInfection Thermal conductionThermal conduction Biological reaction to implantsBiological reaction to implants Young dogs?????Young dogs?????

AGEAGE Post operative time forPost operative time for

Plate removalPlate removal

1.1. Under 3 monthsUnder 3 months

2.2. 3-6 months3-6 months

3.3. 6-12 months6-12 months

4.4. Over 1 yearOver 1 year

4 weeks4 weeks

2-3 months2-3 months




Radiographs should document Radiographs should document healing prior to removalhealing prior to removal Unless implant failureUnless implant failure

Warn owners about potential for Warn owners about potential for bone breakagebone breakage Cage rest required after plate removalCage rest required after plate removal

Good idea to culture implantsGood idea to culture implants

Plating is superior over other methodPlating is superior over other method

IM pins are cheaper than plates and IM pins are cheaper than plates and interfere with blood supply lessinterfere with blood supply less

Little equipment is required for pin Little equipment is required for pin placementplacement

IM pins can migrate, especially if IM pins can migrate, especially if motion is presentmotion is present

IM pins are not ideal for comminuted IM pins are not ideal for comminuted or transverse fractures or transverse fractures

Advantages of one over anotherAdvantages of one over another Interlocking nails counteract all fracture forces Interlocking nails counteract all fracture forces

and may do it better than platesand may do it better than plates

Interlocking nails do require a lot of equipment Interlocking nails do require a lot of equipment and some expertise to place them, but are and some expertise to place them, but are cheaper than platescheaper than plates

Interlocking nails are limited by the type of Interlocking nails are limited by the type of fracture you can repair and the size of the fracture you can repair and the size of the animalanimal

Plating advantagePlating advantage

Plates counteract all fracture forcesPlates counteract all fracture forces Plates are versatile and can be applied to many Plates are versatile and can be applied to many

fracture types and animal sizesfracture types and animal sizes Plating requires some expertise and expensive Plating requires some expertise and expensive

equipmentequipment Plating requires an aggressive surgical Plating requires an aggressive surgical

approach in most instancesapproach in most instances Plates may interfere with blood supply more Plates may interfere with blood supply more

than any of the other implantsthan any of the other implants Clinically not a major problemClinically not a major problem

Advantages of one over anotherAdvantages of one over another

Open approaches can delay fracture Open approaches can delay fracture healing and predispose to infectionhealing and predispose to infection Plates/screwsPlates/screws Interlocking nails Interlocking nails

Closed approaches can be used withClosed approaches can be used with IM pinsIM pins

External fixatorExternal fixator Interlocking nails require a limited approachInterlocking nails require a limited approach

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Principles of Plating