healing process

8/9/2019 Healing Process

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Chapter 5Chapter 5

The Healing ProcessThe Healing Process


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OverviewOverview

Injuries to the musculoskeletalInjuries to the musculoskeletal

system can result from a widesystem can result from a wide

variety of causesvariety of causes.. Each of theEach of themajor components of themajor components of the

musculoskeletal systemmusculoskeletal systemhavehave

varying capacities to healvarying capacities to heal


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MusculoskeletalMusculoskeletal

InjuriesInjuries Injuries to the soft tissues can beInjuries to the soft tissues can be

classied as primary or secondaryclassied as primary or secondary

! PrimaryPrimary injuries can be self"in#icted$injuries can be self"in#icted$caused by another individual orcaused by another individual or

entity$ or caused by the environmententity$ or caused by the environment %cute%cute

&hronic&hronic

%cute on chronic%cute on chronic


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MusculoskeletalMusculoskeletal

InjuriesInjuries 'econdary'econdary injuries are essentiallyinjuries are essentially

the in#ammatory response thatthe in#ammatory response that

occurs with the primary injuryoccurs with the primary injury


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Wound healingWound healing

(ortunately$ the majority of soft tissue(ortunately$ the majority of soft tissue

injuries heal without complication in ainjuries heal without complication in a

predictable series of eventspredictable series of events However$ healing abnormalities canHowever$ healing abnormalities can

occur. These abnormalities can be dueoccur. These abnormalities can be due

to such complications asto such complications as

! InfectionInfection

! &ompromised circulation&ompromised circulation

! )europathy)europathy


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Wound healingWound healing

Three main phasesThree main phases

! In#ammatoryIn#ammatory

! ProliferativeProliferative

! *emodeling*emodeling


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Infammatory phaseInfammatory phase

The reaction that occursThe reaction that occurs

immediately after woundingimmediately after wounding

includes a series of defensiveincludes a series of defensiveevents that involves theevents that involves the

recognition of a pathogen and therecognition of a pathogen and the

mounting of a reaction against it.mounting of a reaction against it.This reaction involves bothThis reaction involves both

coagulation and in#ammationcoagulation and in#ammation


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&oagulation. %part from an initial period&oagulation. %part from an initial periodof vasoconstriction lasting for +",-of vasoconstriction lasting for +",-minutes$ tissue injury causesminutes$ tissue injury causesvasodilation$ the disruption of bloodvasodilation$ the disruption of bloodvessels and etravasation of bloodvessels and etravasation of bloodconstituents$ including plateletsconstituents$ including platelets

The main functions of the eudate are toThe main functions of the eudate are to

! Provide cells capable of tissue reconstructionProvide cells capable of tissue reconstruction! /ilute microbial toins/ilute microbial toins

! *emove contaminants present in the wound*emove contaminants present in the wound


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In#ammation. In#ammation is mediatedIn#ammation. In#ammation is mediated

by chemotactic substances$ includingby chemotactic substances$ including

anaphylatoinsanaphylatoins

$ which$ which

attract neutrophilsattract neutrophils

and monocytesand monocytes

! )eutrophils are white blood cells that bind to)eutrophils are white blood cells that bind to

microorganisms$ internali0e them$ and killmicroorganisms$ internali0e them$ and kill

themthem

! 1onocytes are white blood cells that develop1onocytes are white blood cells that develop

into macrophages$ and provide immunologicalinto macrophages$ and provide immunological

defences against many infectious organismsdefences against many infectious organisms


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The complete removal of theThe complete removal of the

wound debris marks the end ofwound debris marks the end of

the in#ammatory processthe in#ammatory processThis stage can last from ,"2 daysThis stage can last from ,"2 days

to longer than 2 monthsto longer than 2 months


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&ommon causes for a persistent chronic&ommon causes for a persistent chronicin#ammatory response includein#ammatory response include! Infectious agentsInfectious agents

! Persistent virusesPersistent viruses

! Hypertrophic scarringHypertrophic scarring

! Poor blood supplyPoor blood supply

! EdemaEdema

! *epeated direct trauma*epeated direct trauma

! Ecessive tension at the wound siteEcessive tension at the wound site

! Hypersensitivity reactionsHypersensitivity reactions


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&linically$ during the in#ammatory&linically$ during the in#ammatory

phase there is painphase there is pain

! %t rest%t rest! 3ith active motion3ith active motion

! 3hen specic stress is applied to the3hen specic stress is applied to the

injured structureinjured structure

The pain$ if severe enough$ can resultThe pain$ if severe enough$ can resultin muscle guarding$ and a loss ofin muscle guarding$ and a loss of

function.function.


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Prolierative phaseProlierative phase

&haracteristic changes during this&haracteristic changes during this

phase includephase include

! &apillary growth&apillary growth

! 4ranulation tissue formation4ranulation tissue formation

! (ibroblast proliferation with collagen(ibroblast proliferation with collagen

synthesis and increasedsynthesis and increasedmacrophage and mast cell activitymacrophage and mast cell activity


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Prolierative phaseProlierative phase

This phase lasts from + to ,+This phase lasts from + to ,+

days$ and often up to ,- weeksdays$ and often up to ,- weeks

depending on the type of tissue$depending on the type of tissue$and the etent of damage.and the etent of damage.


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emodeling phaseemodeling phase

The remodeling phase of woundThe remodeling phase of wound

healing involves a conversion ofhealing involves a conversion of

the initial healing tissue to scarthe initial healing tissue to scartissuetissue

This lengthy phase of contraction$This lengthy phase of contraction$

tissue remodeling and increasingtissue remodeling and increasingtensile strength in the wound laststensile strength in the wound lasts

for up to a yearfor up to a year


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emodeling phaseemodeling phase

Imbalances in collagen synthesis andImbalances in collagen synthesis anddegradation during this phase ofdegradation during this phase ofhealing may result in hypertrophichealing may result in hypertrophicscarring or keloid formationscarring or keloid formation

If left untreated$ the scar formed is lessIf left untreated$ the scar formed is lessthan 5-6 of its original si0ethan 5-6 of its original si0e

'carring that occurs parallel to the line'carring that occurs parallel to the lineof force of a structure is less vulnerableof force of a structure is less vulnerableto re"injury than a scar$ which isto re"injury than a scar$ which isperpendicular to those lines of forceperpendicular to those lines of force


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Muscle healingMuscle healing

The capacity of muscle forThe capacity of muscle for

regeneration is based primarily uponregeneration is based primarily upon

the type and etent of injurythe type and etent of injury 7roadly speaking$ there are three7roadly speaking$ there are three

phases in the healing process of anphases in the healing process of an

injured muscleinjured muscle

! The destruction phaseThe destruction phase

! The repair phaseThe repair phase

! The remodeling phaseThe remodeling phase


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!igament and tendon!igament and tendon

healinghealing Healing of ligaments and tendonsHealing of ligaments and tendons

generally can be broken downgenerally can be broken down

into four overlapping phasesinto four overlapping phases! I.I. HemorrhagicHemorrhagic

! II.II.In#ammatoryIn#ammatory

! III.III. ProliferationProliferation! I8.I8. *emodeling and maturation*emodeling and maturation


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"rticular cartilage"rticular cartilage

healinghealingThe capacity of articular cartilageThe capacity of articular cartilage

for repair is limitedfor repair is limited

The repair response of articularThe repair response of articularcartilage varies with the depth ofcartilage varies with the depth of

the injurythe injury


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healinghealing Injuries of the articular cartilageInjuries of the articular cartilage

that do not penetrate thethat do not penetrate the

subchondral bone becomesubchondral bone becomenecrotic and do not healnecrotic and do not heal

These lesions usually progress toThese lesions usually progress to

the degeneration of the articularthe degeneration of the articularsurfacesurface


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healinghealing Injuries that penetrate theInjuries that penetrate the

subchondral bone undergo repairsubchondral bone undergo repair

due to access to the bone9s blooddue to access to the bone9s bloodsupplysupplyThese repairs are usuallyThese repairs are usually

characteri0ed ascharacteri0ed as

! (ibrous(ibrous! (ibrocartilaginous(ibrocartilaginous

! Hyaline"like cartilaginousHyaline"like cartilaginous


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#one healing#one healing

The striking feature of boneThe striking feature of bone

healing$ compared to healing inhealing$ compared to healing in

other tissues$ is that repair is byother tissues$ is that repair is bythe original tissue$ not scar tissuethe original tissue$ not scar tissue

7one healing involves a7one healing involves a

combination of intramembranouscombination of intramembranousand endochondral ossicationand endochondral ossication


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In classic histologic terms$In classic histologic terms$

fracture healing has been dividedfracture healing has been divided

into two broad phasesinto two broad phases! Primary fracture healingPrimary fracture healing

! 'econdary fracture healing'econdary fracture healing


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Primary healing involves a directPrimary healing involves a direct

attempt by the corte toattempt by the corte to

reestablish itself once it hasreestablish itself once it hasbecome interruptedbecome interrupted

7one on one side of the corte7one on one side of the corte

must unite with bone on the othermust unite with bone on the otherside of the corte to reestablishside of the corte to reestablish

mechanical continuitymechanical continuity


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'econdary healing involves'econdary healing involves

responses in the periosteum andresponses in the periosteum and

eternal soft tissues with theeternal soft tissues with thesubse:uent formation of a callussubse:uent formation of a callus

The majority of fractures heal byThe majority of fractures heal by

secondary fracture healingsecondary fracture healing

healing process

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