Degenerative Joint Disease and Traumatic Arthritis

8/13/2019 Degenerative Joint Disease and Traumatic Arthritis

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Degenerative Joint Disease and Traumatic Arthritis(LastUpdated: 1-Jan-1985)

A. J. Lipowitzand C. D. Newton

Section One: Degenerative Joint Disease

Degenerative oint disease (DJD) is a common disorder o! humans and anima"s# $t is

genera""% regarded as a nonin!"ammator% condition o! articu"ar carti"age resu"ting !rom

natura" aging& trauma& or disease# 'an% names have een app"ied to the condition

ho*ever& osteoarthritis and degenerative oint disease are t*o o! the most common and

*i"" e used interchangea"% in this chapter#

DJD has een recogni+ed in anima"s !or a "ong time# ,a"eopatho"ogic eamination o!

dr%-one preparations has sho*n "esions compara"e to those o! DJD in !ossi" repti"es

!rom the 'eso+oic period#(./) A"though caution must e used in the interpretation o!

these !indings& the% point out that articu"ar disease has a!!ected anima"s since anima"s

have *a"0ed on earth#

DJD has een c"assi!ied in man% *a%s# ne c"assi!ication descries DJD as either

primar% or secondar%#(1/&28) ,rimar% DJD is that *hich occurs in diarthrodia" oints in

*hich there has een no 0no*n previous trauma or disease# This primar% condition is

est eemp"i!ied % the Joint changes seen in o"der anima"s# ,rimar% DJD is genera""%regarded as an aging phenomenon (3&1/&28) in *hich deterioration o! the articu"ar

carti"age occurs& "eading to the characteristic oint changes#

As the name imp"ies& secondar% DJD is the resu"t o! some insu"t to the a!!ected oint#

Usua""% it is a "oca" phenomenon rather than a s%stemic disease& a"though some s%stemic

diseases that a!!ect oints ma% u"timate"% "ead DJD# Loca" insu"t *ith resu"ting

degenerative changes is est eemp"i!ied % crania" cruciate "igament rupture#

T*o maor categories o! articu"ar disease are descried nonin!"ammator% and

in!"ammator%#(1/&28) DJD is p"aced in the nonin!"ammator% categor% a"though an

intermittent in!"ammator% component is recogni+ed# ther conditions o! so-ca""ed

nonin!"ammator% articu"ar disease inc"ude traumatic arthritis& mechanica" anorma"ities

such as torn menisci& aseptic necrosis& neuroarthropath%& and neop"asia# The

in!"ammator% categor% is sudivided into an in!ectious section& *hich inc"udes articu"ar

disease caused % acteria"& !unga"& vira"& and proto+oa" organisms& and a nonin!ectious

section& *hich itse"! is !urther divided into t*o sucategories: immuno"ogic and

nonimmuno"ogic# The immune-mediated articu"ar diseases& such as rheumatoid arthritis

and s%stemic "upus er%thematosus& and nonimmune in!"ammator% conditions such as

cr%sta"-induced arthritis& (i#e#& gout& pseudogout) and chronic hemarthrosis *i"" e dea"t

*ith in other sections o! this tet#

'ature articu"ar carti"age is a uni4ue tissue in that it does not incorporate its o*n direct
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"ood supp"%# The usua" tissue response to insu"t is one o! in!"ammation& *hich re"ies on

intrinsic vascu"arit%# ithout vascu"arit%& articu"ar carti"age response to insu"t is

di!!erent than that o! other tissue# DJD is a se4ue" to carti"age insu"t& ut ecause

carti"age "ac0s intrinsic vascu"arit% it does not ecome in!"amed& thus the designation o!

DJD as a nonin!"ammator% condition#

6o*ever& DJD is not a condition o! articu"ar carti"age a"one# The s%novia" memrane

"ining the a!!ected oint cavit% is a"so invo"ved# This tissue& *ith its high degree o!

intrinsic vascu"arit%& ehiits in!"ammator% change# The intensit% o! these changes

varies *ith the etent o! the insu"t to the oint and the duration o! the condition# The

in!"ammator% changes o! DJD are a"so re!"ected in the ce""u"ar constituents o! the

s%novia" !"uid# Tota" ce"" counts need not e high& ut certain ce"" t%pes *i"" e seen&

con!irming the in!"ammator% nature o! DJD# Thus& a c"assi!ication s%stem !or canine

articu"ar disease *as deve"oped to re!"ect these in!"ammator% changes and is presented

inTa"e 87-1#

TAL 87-1 "assi!ication o! Articu"ar Disease

Pathology

The characteristic structura" changes that t%pi!% DJD are disorgani+ation and "oss o!articu"ar sur!aces and pro"i!eration o! tissues in and adacent to these sur!aces# The

precise se4uence o! histo"ogic change in a!!ected articu"ar tissues is not 0no*n *ith

aso"ute certaint%# ;or instance& in primar% DJD it is not 0no*n *hether s%novia"

memrane changes precede articu"ar carti"age changes# 'uch o! the sophisticated

histo"ogic and iochemica" research into DJD has concentrated on articu"ar carti"age#

DJD has een oserved in human autops% specimens !rom persons *ho reported"% *ere

as%mptomatic during "i!e# This has "ed to the h%pothesis that these "esions ma% e

considera"% di!!erent than those seen in the oints o! s%mptomatic patients#

Advancing age is important in the pathogenesis o! DJD ut is proa"% not the primar%

cause o! the disease# hi"e carti"age rea0do*n is more !re4uent in o"der humans andanima"s& a"" oints are not a!!ected concomitant"%& and it is evident that "oca" !actors p"a%

a maor pathogenic ro"e# ith advancing age a considera"e numer o! chemica"&

io"ogic& and mechanica" a"terations occur in norma" articu"ar carti"age# $t has een

stated that i! aging itse"! is considered norma"& so then too shou"d these changes# (3)

Load earing is important in the norma" io"og% o! oints# (2/) As descried in hapter

8/& the nutrient transport to articu"ar carti"age via the s%novia" !"uid is dependent on

oint motion and *eight earing# $n !act& degenerative changes o! articu"ar carti"age

have een demonstrated in studies in *hich "ims *ere immoi"i+ed !or var%ing periods

o! time#(9) The a!!ected oints *ere a""o*ed no motion or *eight earing# At the end o!

5 *ee0s& de!inite changes in articu"ar carti"age& some indistinguisha"e !rom DJD& *erenoted# onverse"%& heav% use o! *e"" a"igned oints rare"% contriutes to carti"age

rea0do*n# (15)
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The p"acement on oints o! anorma" ph%sica" stresses that accompanies such conditions

as chronic su"uation& hip d%sp"asia& s"ipped epiph%ses& and aseptic necrosis< p"a%s a

vita" pathogenic ro"e in the deve"opment o! DJD# =tudies have sho*n that oint

remode"ing norma""% occurs *ith advancing age& thus changing oint contour and

articu"ar sur!ace congruit%# Joints norma""% are not entire"% congruous ut rather haveareas o! >contact> and >noncontact#>(15) ith increased "oads on oints& the areas o!

contact increase in si+e& and greater oint sur!ace congruit% is achieved# ith advancing

age& minor a"terations in carti"age a""o* greater congruit% *ith sma""er and sma""er

"oads& thus ringing areas o! norma" noncontact in the intact oint into contact# =uch

a"terations in congruit% "ead to erosive and osteoph%tic changes# These "esions o!

>"imited progression> have een oserved in human autops% specimens !rom persons

*ho *ere thought to e as%mptomatic during "i!e# hi"e the gross appearance and

"ocation o! these "esions di!!er some*hat !rom those seen in patients *ith c"inica""%

s%mptomatic oint disease& the iochemica" characteristics o!< the "esions di!!er "itt"e

!rom those o! the c"inica" condition# (15)

The c"assic morpho"ogic changes o! osteoarthritic articu"ar carti"age egin *ith

!iri""ation&(3&15&3.) a "oca" sur!ace disorgani+ation invo"ving a sp"itting o! the

super!icia" "a%ers o! the carti"age# The ear"% sp"itting is tangentia" *ith the carti"age

sur!ace& !o""o*ing the aes o!< the predominant co""agen und"es# 6ori+onta" !"a0ing o!

carti"age occurs a"ong *ith the deve"opment o! sha""o* pits or c"e!ts perpendicu"ar to

the carti"age sur!ace# ventua""%& the sp"itting etends deeper& a"tering the norma"

arrangement o! the co""agen und"es# As the disease progresses& the c"e!ts etend

entire"% through the carti"age to its unction *ith suchondra" one#

ith disease progression& !iri""ation continues and is accompanied % s%novia"

h%perp"asia and adacent osteoph%te !ormation# ontinued deterioration o! articu"ar

carti"age "eads to eposure o! suchondra" one and a more genera"i+ed s%novia"

change# =evere end-stage DJD is characteri+ed % etensive suchondra" one eposure

and tremendous de!ormit% in oint sur!ace contour& o!ten "eading to "uation#

hi"e !iri""ation is genera""% accepted as the !irst signi!icant change in articu"ar

carti"age readi"% identi!ia"e % "ight microscop%& mo"ecu"ar& chemica"& and other

ph%sica" changes precede !iri""ation# Thus& !iri""ation shou"d e considered as a

common microscopic endpoint o!< oth norma" and anorma" occurrences that "ead to

carti"age !ai"ure#(3)

To understand the processes "eading to carti"age !ai"ure& it is important to "oo0 at the

ce""u"ar processes and iochemica" structure o! norma" carti"age# 6%poce""u"ant% o!

norma" articu"ar carti"age as compared *ith other tissues is a stri0ing !eature# The

greatest portion o! articu"ar carti"age mass is composed o! a macromo"ecu"ar

etrace""u"ar matri surrounding the chondroc%tes# ecause o! their appearance under

"ight microscop%& articu"ar carti"age chondroc%tes *ere once thought to e rather inert

or inactive# $t is no* *e"" recogni+ed that the maintenance and production o! the

etrace""u"ar matri % the chondroc%te is an active and continuing process#

?orma" mature articu"ar carti"age is divided histo"ogica""% into !our distinct +ones ased

on the arrangement and orientation o! its ce""u"arit%#(3.) The most super!icia" +one& thatc"osest to the articu"ating =ur!ace& is the tangentia" +one# 6ere the !"attened ce""s have
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their "ong aes para""e" to the articu"ar sur!ace# The u"trastructura" appearance o! these

ce""s has suggested to some that the% are !iro"astic in nature#(3.) $mmediate"% eneath

the tangentia" +one& the ce""s are more rounded and are random"% oriented# This is the

transitiona" +one# The chondroc%tes in this area are metao"ica""% active& producing

co""agen and proteog"%can# eneath this region is the radia" +one in *hich ce""s are

arranged in short co"umns perpendicu"ar to the articu"ar sur!ace# These ce""s are sma""erthan those immediate"% aove and appear "ess active# The ca"ci!ied +one& *ith its

p%0notic ce""s surrounded % ca"ci!%ing matri& resides deep to the radia" +one#

arti"age matri is a ge"-"i0e sustance composed o! *ater and the macromo"ecu"ar

po"%anionic sustances& proteog"%can and co""agen#(15&3.) A"though produced

separate"%& proteog"%can is "in0ed to co""agen etrace""u"ar"%# ,roteog"%cans are e"astic

mo"ecu"es that epand in so"ution and strong"% resist compression into a sma""er

vo"ume# ,roteog"%can consists o! a protein core or ac0one to *hich are attached side

chains o! g"%cosaminog"%cans (@A@s)# Three distinct @A@s have een identi!ied:

chondroitin 3-su"!ate& chondroitin /-su"!ate& and 0eratin su"!ate# ecause o! their

repe""ing negative charges& the @A@s are attached to the protein core at near"% rightang"es# $n the matri& the proteog"%can is arranged in high-mo"ecu"ar-*eight aggregates

!ormed % noncova"ent association et*een proteog"%can suunits& h%a"uronic acid and

"in0age protein#

ith norma" aging the ratio et*een the various @A@s changes# $n immature carti"age

the ratio et*een chondroitin 3-su"!ate and chondroitin /-su"!ate is near"% 1:1& and there

is ver% "itt"e 0eratin su"!ate# As aging progresses the ratio ecomes 1:3& and % midd"e

age the concentrations o! the 0eratin su"!ate and chondroitin /-su"!ate are near"% e4ua"

and account !or a"most 9B o! the @A@ content o! articu"ar carti"age#

,roteog"%can o! norma" articu"ar carti"age is constant"% degraded and res%nthesi+ed its

ha"!-"i!e has een estimated at 15 da%s#(3.) The remode"ing s%stem appears to e

en+%me dependent# L%so+%mes such as cathepsin-D and ar%"su"!atase are thought to e

t*o o! the primar% en+%mes responsi"e !or proteog"%can degradation#

Li0e proteog"%can& co""agen ma0es up aout 5B o! the dr% *eight o! articu"ar

carti"age#(3.) o""agen is composed o! !iers and !iri"s the structures o! *hich are

comp"e he"ices o! "inear"% arranged amino acids# o""agen o! s0in di!!ers !rom that o!

articu"ating sur!aces as a resu"t o! di!!erent amino acid arrangements#(19&27&.1) $n ear"%

studies it *as discovered that co""agen o! s0in and tendon *as composed o! three

intert*ined amino acid chains& t*o o! *hich *ere !ound to e identica"# The t*oidentica" chains *ere designated a"pha-1 and the dissimi"ar chain *as designated a"pha-

2# n !urther eamination o! articu"ar carti"age& the a"pha-1 chains *ere sho*n to e o!

t*o t%pes that di!!ered !rom each other % a"teration in amino acid se4uence# $t *as

!urther discovered that co""agen o! articu"ar carti"age *as composed o! three identica"

a"pha chains di!!ering !rom the a"pha-1 o! other tissues % various amino acid

sustitutions# Thus& t*o t%pes o! a"pha-1 chains *ere recogni+ed: a"pha-1 ($) present in

s0in& tendon& one& and carti"age and a"pha-" ($$) present on"% in articu"ar carti"age#

These t*o t%pes o! co""agen *ere designated t%pes $ and $$ respective"%# The maor

distinctions et*een the t*o t%pes are the di!!erences in amino acid composition and

the asence o! an a"pha-2 chain in t%pe $$ co""agen# $n addition& there are di!!erences in

the pattern o! intramo"ecu"ar and intermo"ecu"ar cross "in0ages# ight other t%pes o!co""agen are 0no*n to eist# T%pe $$$ is !ound in s0in and the *a""s o! the uterus and
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arteries& and t%pes $C and C are !ound in asement memranes o! various organs#(27)

The arrangement o! co""agen !iers *ithin canine articu"ar carti"age is simi"ar to that in

human articu"ar carti"age& *ith various and distinct +ones noted#(35) The most

super!icia" "a%er is the "amina sp"endens& composed o! !ine !irous materia"# eneath

this is the tangentia" "a%er in *hich tight"% pac0ed co""agen !iers are para""e" *ith thearticu"ar sur!ace# These !irous und"es are at random ang"es to each other& ut their

uni!orm orientation is para""e" *ith the sur!ace# $n the transitiona" +one& the !iers

assume a more random orientation& a"though in the vicinit% o! the chondroc%tes the

!iers s*eep in a"most capsu"ar !ashion aout the "acunae# A distinct "ine o! demarcation

is not seen et*een the transitiona" +one and the deeper radia" +one# 6o*ever& co""agen

!ier orientation ecomes "ess random and more perpendicu"ar to the articu"ar sur!ace in

the radia" +one#

@enera""% spea0ing& the numer o! co""agen !iri"s per unit area decreases *ith

increasing distance !rom the articu"ar sur!ace# $n addition& the diameter o! the co""agen

!iri"s increases *ith increasing distance !rom the sur!ace#(35)

cessive or anorma" use and direct inur% such as !ractures or "igamentous disruptions

have a"*a%s een the ovious ep"anation !or DJD deve"opment# et it has een sho*n

in humans that *hat ma% e considered greater than norma" use does not necessari"%

"ead to degenerative changes# $n a stud% comparing !ormer runners *ith a contro"

popu"ation o! nonrunners& the runners had "ess DJD o! the primar% t%pe#(15) vidence

has not %et een produced that sho*s that ecessive use *ithout inur% "eads to DJD#(3)

hi"e the etio"og% o! DJD ma% e mu"ti!actoria" and the rate o! morpho"ogic changes

varia"e& the end resu"t is a decrease in oint motion and !unction& an increase in

de!ormit%& oint instai"it%& and pain# DJD is common"% seen in var%ing degrees

associated *ith hip d%sp"asia& crania" cruciate "igament rupture& ununited anconea"

process& ununited (!ragmented) coronoid process& osteochondritis dissecans&

"igamentous inuries& and as a se4ue"a to articu"ar !ractures#

Tissues respond to insu"t in a characteristic manner& *ith the magnitude o! responsive

change compara"e to the etent o! insu"t# The degree o! articu"ar carti"age response to

inur% "i0e*ise *i"" var% *ith the degree o! damage# $t shou"d e recogni+ed that the

!o""o*ing description o! the morpho"ogic and iochemica" changes o! articu"ar carti"age

in response to insu"t and the suse4uent deve"opment o! DJD is presented more as an

overa"" revie* o! these changes and not as a de!initive se4uence o! events that occurs inever% instance o! DJD#

GROSS CHANGES

DJD changes are !irst recogni+ed as a !oca" area o! du""ness on the articu"ar carti"age

sur!ace#(28) This is accompanied % a co"or change !rom the more norma" g"istening

*hite to a mott"ed gra% or %e""o*# ;iri""ation& as descried aove& is occurring in these

regions# ecause o! a"teration in the matri composition& these areas a"so ecome so!ter

than norma"# hondroc%tes adacent and super!icia" to the so!tened areas ecome more

numerous& *hi"e those *ithin the =o!tened areas decrease in numer# $n eperimenta""%

induced DJD& chondroc%te densit% increases in areas adacent to the sp"its or c"e!ts andthe numer o! "acunae *ith t*o or more nuc"ei a"so increases#(17) As the !iri""ation
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continues& c"ones o! t*o or more ce""s are particu"ar"% aundant around severe"%

!iri""ated sites# This response o! increased numers o! carti"age ce""s at the initia" site o!

inur% has een vie*ed % some as an attempt at intrinsic carti"age repair (;ig# 87-1)#

(28)

As the c"e!ts and sp"its in the co""agen deepen& arasion o! the !iri""ated carti"agecontinues& eventua""% eposing the under"%ing suchondra" one# ith continued

disruption o! the osteochondra" unction& hemorrhage and one necrosis occur#

steochondra" repair ta0es the !orm o! granu"ation tissue and !irocarti"age# ith

continuing "oss o! the carti"age sur!ace and increased one eposure& the one ecomes

sc"erotic# $n severe cases o! DJD the eposed one ma% actua""% ecome *e"" *orn&

smooth& and po"ished# =uch one is descried as eurnated# (28&./)

;$@# 87-1 ;iri""ation o! articu"ar carti"age# "e!ts and

sp"its egin on the carti"age sur!ace para""e" *ith the

articu"ar p"ane# The% then etend deeper into the carti"age

sustance ecoming perpendicu"ar to the oint sur!ace# (6E /)

Areas o! one rare!action& or >c%sts&> ma% appear eneath the eurnated sur!aces# These

spaces !ormed % the "oss o! traecu"ae are a !irom%oid degeneration o! the marro*#

n occasion& !ragments o! dead one& carti"age& and amorphous materia" ma% a"so e

!ound *ithin these areas# ecause these "esions on"% rare"% contain poc0ets o! mucoid

!"uid and do not have a !irous order or capsu"e& the% are not considered true c%sts#

(./)

Another on% change that o!ten accompanies DJD is that o! eoph%tic gro*th at the

margins o! the articu"ar sur!ace# 'argina" osteoph%tes occur at the unction or inter!ace

et*een the articu"ar carti"age and s%novia" memrane# The% ma% appear as

protuerances into the oint space or deve"op *ithin capsu"ar or "igamentous

attachments at the oint margins# The direction o! osteoph%te !ormation is governed %

the "ine o! mechanica" !orce imparted to the area o! gro*th#

steoph%te !ormation egins as a deposition o! minera" outside the eisting on%

corte#(/) ;urther deposition o! ne* one& resorption& and remode"ing u"timate"%

produce a mature osteoph%te# apped % a h%a"ine or !irocarti"age sur!ace& mature

osteoph%tes communicate !ree"% *ith the marro* spaces o! the one !rom *hich the%arose (;igs# 87-2 and87-.)#

$n eperiments in *hich the anterior cruciate "igament o! dogs *as severed to produce

DJD& eginning osteoph%te deve"opment *as detected % microangiographic techni4ues

7 da%s a!ter "igament transection 'acroscopica""% and radiographica""%& osteoph%tes

cou"d e seen at 2 *ee0s and 5 *ee0s respective"% !o""o*ing "igament transection#

hi"e in itse"! the presence o! osteoph%tes (i#e#& *ithout carti"aginous de!ects) is

proa"% not evidence !or a diagnosis o! DJD& it is indicative o! anorma" activit%

*ithin a oint#

A third signi!icant on% change o! DJD is the deve"opment o! sc"erosis in the
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suchondra" area# The one in this area ecomes more dense *ith increasing "oss o! the

articu"ar carti"age aove# This sc"erosis has een descried as eing the resu"t o!

increased "oads p"aced on the one ecause o! the articu"ar carti"age "oss#(3&28)

;$@# 87-2 steoph%tes on "atera" aspect o! "atera" !emora"cond%"e# steoph%tes deve"op at the inter!ace o! articu"ar

carti"age and s%novia" memrane Cascu"arit% o! the s%novia"

memrane can e seen (arro*)#

;$@# 87-. steoph%tes on the proima" aspect o! the !emora"

troch"ea#

BIOCHEMICA CHANGES

;or the most part& iochemica" a"terations in articu"ar carti"age undergoing changes

associated *ith DJD precede the characteristic macroscopic changes#(3&18) hi"e there

are some con!"icting reports regarding the changes in *ater content& production and t%pe

o! co""agen present& and the ratio o! proteog"%can constituents& the genera" consensus is

that *ater content increases a"ong *ith an initia" increase in chondroc%tic s%nthesi+ing

activities# ith progression o! DJD and continued "oss o! articu"ar carti"age sustance

and there!ore "oss o! the chondroc%tes themse"ves& it is ovious that chondroc%te

activities decrease#

The *ater content o! norma" articu"ar carti"age is et*een 72B and 78B#(15) $n DJD

not on"% is the *ater content increased ut the *ater is more tight"% ound and there!ore

"ess !ree"% echangea"e *ith the oint space# (15&3.) $t is suspected that o*ing to

proteog"%can dep"etion& "arger amounts o! *ater ecome more avid"% ound to co""agen#

The "oss o! *ater-trans!er capai"ities ma% have a de"eterious e!!ect on chondroc%te

nutrition& articu"ar carti"age e"asticit%& and oint "urication#(3.)

hi"e the tota" co""agen content o! osteoarthritis articu"ar carti"age is simi"ar to that o!norma" carti"age& the composition and orientation o! the co""agen !iri"s are changed#

(3.) in the upper region o! degenerative carti"age the tota" numer o! co""agen !iri"s

remains near"% the same as norma" carti"age ho*ever& there is a decrease in the numer

o! "arge-diameter !iri"s#(35) As might e epected& !iri" orientation is severe"% a"tered#

Father than remaining in tight"% pac0ed und"es para""e" *ith the articu"ar =ur!ace& the

!iri"s are in a "ooser arrangement *ith a random orientation# These !indings o! a higher

proportion o! sma""-diameter co""agen !iri"s and random orientation o! the !iri"s are

a"so characteristic o! the deeper "a%ers o! the a!!ected carti"age#

$n addition& the t%pe o! co""agen !iri" !ound in osteoarthritis articu"ar carti"age is

di!!erent than that !ound in norma" carti"age# =evera" reports have sho*n thatosteoarthritis chondroc%tes produce not on"% t%pe $$ co""agen ut sustantia" amounts o!
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t%pe $ co""agen& that *hich is usua""% !ound in s0in and one#("5&.9&3.) hi"e evidence

to the contrar% has a"so een reported&> it is genera""% e"ieved that the changes in the

t%pe o! co""agen !irin and the a"terations in their si+e and orientation serve to a!ter the

mechanica" properties o! arthritic carti"age#(3.)

$t is genera""% accepted that the tota" proteog"%can content o! osteoarthritis articu"arcarti"age is decreased and that the decrease is direct"% proportiona" to the disease

severit%# (15) 6o*ever& *hi"e tota" @A@ content o! a!!ected carti"age is diminished& not

a"" @A@ components are a!!ected e4ua""%# hen compared *ith norma" carti"age& there

is a re"ative decrease in 0eratin su"!ate and an increase in chondroitin 3-su"!ate such as is

!ound in norma" %oung or immature carti"age# Thus& chondroc%tic s%nthesi+ing activit%

continues in a!!ected carti"age ut the products produced are di!!erent# (13&18) hat

triggers this a"teration in production is not 0no*n& ut it has een suggested that it ma%

e an attempt to hea" the carti"aginous de!ects#(15)

$t must e noted that these changes are !ound on"% in areas o! carti"aginous "esions such

as !iri""ation# $n intact areas o! carti"age !rom the same oint sur!ace& @A@ content isnorma"# (.9) $n addition& @A@ content is increased in areas o! osteoph%tic activit%#

$n "ater stages o! DJD& there is a continued decrease in @A@ s%nthesis and a re"ative

decrease in chondroitin su"!ate compared *ith 0eratin su"!ate#(3) These decreases

corre"ate *e"" *ith the histo"ogic severit% o! the disease#

CES O! AR"IC#AR CAR"IAGE

There is amp"e evidence to sho* that in the ear"% stages o! DJD there is an increase in

the numer o! chondroc%tes adacent to the sp"its in the carti"age# The rate at *hich ne*

ce""s are produced has een !ound to e proportiona" to the severit% o! the disease ased

on a histochemica" grading s%stem !or ear"% and moderate "esions#(15) These ce""s&

particu"ar"% near the articu"ar sur!ace& have a microscopic appearance suggestive o!

!iro"asts# U"trastructura""%& the% have an increase in rough endop"asmic reticu"um&

mitochondria& and @o"gi apparatus& *hich are the organe""es associated *ith increased

matri production#(3.) $n addition& some o! these ce""s are !ound to have a decrease in

stored g"%cogen& a"so suggestive o! increased ce""u"ar activit%#(35)

$n advanced severe "esions& ne* ce"" production is decreased and the ce""s present

appear to e undergoing degenerative changes#(3.) Thus it seems as i! the increased

s%nthesi+ing activit% o! @A@ and production o! ne* ce""s cannot 0eep pace *ith the!orces and activities responsi"e !or carti"age destruction# This has een descried as a

!ai"ure> or rea0do*n in the reparative mechanism that accompanies increasing disease

activit%#("5)

L%sosoma" activit% and en+%matic degradation are a"so !actors in the osteoarthritis

process and ma% in !act ep"ain ho* there can e a "oss o! matri components in the

!ace o! increased matri s%nthesis# hi"e the initiating !actors !or en+%me re"ease are

not 0no*n& there is no dout that the% are present in increased amounts in osteoarthritis

carti"age# Acid phosphatase& ar%"su"!atase A and # and cathepsin and D have een

!ound in greater amounts than norma" in carti"age !rom a!!ected oints# (.&5&.3) These

en+%mes a!!ect the matri in various *a%s& ut in genera" the% cause a degradation o!proteog"%can# As mentioned aove& some o! these en+%mes are necessar% !or the norma"
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turnover o! proteog"%can# hat causes their increased production or decreased remova"

is not 0no*n# 6o*ever& it is 0no*n that their activit% contriutes to the rea0do*n o!

the proteog"%can structure and suse4uent "oss o! matri sustance#

,rotease inhiitors are 0no*n to e present in articu"ar arti"age& and it has een

h%pothesi+ed that an impaired ai"it% o! the chondroc%tes to s%nthesi+e these sustances"eads to the "oss o! matri components# (.9) $n this theor%& the degradative en+%mes

norma""% present in articu"ar arti"age are he"d in chec0 % other en+%mes produced %

the chondroc%tes# ut in DJD& !or some un0no*n reason& the protease production is

decreased and there!ore the chec0 he"d on the degradative en+%mes is "ost# hi"e this

h%pothesis has not een proven to date& it remains an interesting concept& especia""% in

"ight o! *hat is 0no*n o! other regu"ator% io"ogic mechanisms#

CHANGES IN S$NO%IA MEMBRANE

The connective tissue that surrounds diarthrodia" oints is designated the oint capsu"e#

$ts outer part& composed o! dense connective tissue rein!orced % tendons andaponeuroses& is termed the !irous capsu"e# The inner part is termed the s%novia"

memrane# The s%novia" memrane has severa" components# $ts inner "a%er& *hich is

immediate"% adacent to the oint sur!ace& is a g"istening tissue composed o!

s%novioc%tes t*o to three ce""s thic0# eneath this is the sus%novioc%tic tissue& a "oose

connective tissue that vanes in depth& vascu"arit%& and amount o! interspersed adipose

tissue# ithin the sus%novioc%tic "a%er are co""agen and e"astic !iers& as *e"" as

!iroc%tes& occasiona" histioc%tes& macrophages& and mast ce""s#

Just as the ear"iest changes o! articu"ar carti"age in primar% DJD have not een

identi!ied& "i0e*ise the ear"iest changes o! s%novia" memrane are not *e"" descried#

This is due to the inaccessii"it% o! the tissues# The insidiousness o! primar% DJD ma0es

it a"" ut impossi"e to produce eperimenta""% or to gain 0no*"edge !rom iops%

specimens "ithe spontaneous disease# $n!ormation aout s%novia" memrane changes in

DJD comes !rom tissues ta0en a!ter the spontaneous disease has een present !or some

time or !rom eperimenta" mode"s o! DJD& *hich more accurate"% re!"ect the changes o!

secondar% DJD#(3/)

Tissue ta0en !rom human patients *ith primar% DJD seen 1 to 1/ %ears !o""o*ing the

onset o! s%mptoms sho*s three over"apping stages o! s%novia" memrane in!"ammation#

(.7) $n the initia" stages& s"ight to moderate s%novioc%te h%pertroph% is noted# There is

a"so an increase in the numer o! s%novioc%tes& thus thic0ening the inner s%novia"memrane "a%er# ithin the sus%novioc%tic +one& !iro"astic pro"i!eration is noted&

a"ong *ith a moderate"% h%peremic change due to "ood vesse"s# The vesse"s are thin"%

surrounded % in!i"trates o! "%mphoc%tes and p"asmoc%tes# ;oca" aggregations o! simi"ar

ce""s are seen occasiona""%# dema& a"though present& is on"% moderate#

$n the progressive stages o! the disease& s%novioc%te h%perp"asia is more prominent&

*ith the "a%er no* eing three to !ive ce"" "a%ers thic0# $ncreases in !iro"astic activit%

are noted in the sus%novioc%tic "a%er& in *hich the !iro"asts are more numerous# $n

addition& an increase in co""agen !iers is seen as *e"" as a signi!icant increase in the

sus%novioc%tic vascu"arit% (;ig# 87-3)#
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;$@# 87-3 =%novia" memrane !rom the sti!"e o! a dog in

*hom the crania" cruciate "igament *as eperimenta""%

transected 8 *ee0s previous"%# The s%novioc%tic "a%er is 5

to 7 ce""s thic0# =uper!icia" ce""s are perpendicu"ar rather

than para""e" *ith the oint space (J)# eginning !irosis o!

the norma" adipose sus%novia" tissues is apparent (arro*)#( 6 E /)

The advanced stage is characteri+ed % a maintenance o! the s%novioc%tic h%pertroph%

and h%perp"asia and a mar0ed h%perce""u"arit% o! !iro"asts in the super!icia" and

deeper regions o! the sus%novioc%tic "a%er# $n severa" p"aces road co""agen !iers are

noted# A"so& in severa" "a%ers the sus%novioc%tic tissues *ith their comp"ement o!

co""agen& !iro"asts& and vesse"s are thro*n into !o"ds or vi""i etending aove the

adacent !"at s%novioc%tic sur!ace and protruding into the oint space# hi"e some vi""i

are norma""% present in the s%novia" memrane& especia""% in those areas o! the oint

capsu"e that undergo a great dea" o! stretching during oint motion& these vi""i areanorma" ecause o! the a"tered architecture o! the s%novioc%tic and sus%novioc%tic

"a%ers#

$n!"ammation o! the s%novia" memrane& characteri+ed % s%novia" ce"" h%pertroph% and

h%perp"asia& p"asma ce"" and "%mphoc%te in!i"tration& and increased vascu"ari+ation o!

the sus%novium& are prominent !eatures o! eperimenta""% produced DJD in the dog#

=us%novia" !irosis is a"so a common !inding#(3/)

The increased !irosis o! the s%novia" tissue and the progressive !ormation o! vi""i cou"d

easi"% contriute to the oint sti!!ness and pain!u" s%mptoms o!ten associated *ith

advanced DJD#

Clinical Presentation

,rimar% DJD is an insidious progressive condition that most common"% a!!ects o"der

anima"s& *hereas secondar% DJD ma% e more acute in onset and occurs in the %oung or

o"d patient# nce the patho"ogic trans!ormation o! the tissues egins& the genera" signs

and s%mptoms are simi"ar#

Dogs *ith DJD are usua""% presented *ith a comp"aint o! "ameness or gait change# (1)

$n some cases the o*ner *i"" state that the anima" has di!!icu"t% in per!orming certain

acts that hereto!ore *ere per!ormed readi"%# 'ost common"%& the anima" is no "onger

a"e to ump *ith as much vigor as he had previous"% or no* has di!!icu"t% in c"iming

a !"ight o! stairs that previous"% *ere easi"% negotia"e# The astute c"inician 0no*s there

are man% a!!"ictions and conditions that produce "ameness andGor gait anorma"ities in

the dog& and one must 0eep an open mind *hen per!orming a ph%sica" eamination on

such patients# ver% o"der @erman shepherd presented *ith hind"im "ameness and

*ea0ness does not have DJD secondar% to hip d%sp"asia& nor does ever% %oung giant

reed dog presented *ith !ore"eg "ameness have osteochondritis dissecans o! the

shou"der#
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=ince the maorit% o! cases o! DJD that occur in the dog are the resu"t o! another

condition& the primar% condition must e diagnosed and treated in order to curtai" the

degenerative processes that are occurring in the a!!ected oint# $n addition& there are

man% conditions that produce "ameness or gait changes in the dog that do not a!!ect the

oints#(.2) ne must e a"e to di!!erentiate these pro"ems !rom those that are articu"ar

diseases# A care!u""% ta0en histor% and thorough ph%sica" eamination& inc"uding aneuro"ogic assessment o! the patient& are necessar% in eva"uating "ameness# The anima"


12/27

shou"d e noted that most in!"ammator% conditions are associated *ith increases in

tissue temperatures and that thermograph% cannot e used to an% signi!icant degree in

di!!erentiating degenerative oint disease !rom other in!"ammator% conditions o! oints#

$n addition to the usua" comp"ete eamination o! a"" od% s%stems& it must e

determined *hether the anima" has a "oca" or s%stemic condition& a"though a "oca"i+edcondition ma% a!!ect mu"tip"e sites# (1/) are!u" 4uestioning o! the o*ner shou"d

accompan% the actua" eamination o! the patient# $t must e determined *hen the

"ameness *as !irst noticed and under *hat circumstances# as there a >traumatic>

incident or an unusua" eperience such as overuseH The pattern o! invo"vement& i! an%&

shou"d e determined# $n *hat order& i! an%& did the oint invo"vement occurH $s the

"ameness more noticea"e a!ter rest or a!ter eerciseH Does the patient >*arm> in or out

o! the "amenessH $s the invo"vement se"!-"imited& migrator%& or progressiveH(1/)

'igrator% means that the process susides in one oint on"% to mani!est itse"! in another#

,rogressive means that the !irst oint remains invo"ved ut additiona" oints ecome

a!!ected as *e""#

,revious treatment shou"d e determined# hat *as given& !or ho* "ong& and *hat

e!!ect did the therap% have on the conditionH $n addition& an% side-e!!ects produced %

the medication must e noted#

Ra&iogra'hic E(a)ination

A"" anima"s suspected o! having articu"ar disease o! an% t%pe must have the appropriate

oints radiographed# The usua" tenets o! good radiographic techni4ue and protoco" must

e !o""o*ed# These inc"ude accurate patient positioning& at "east t*o standard vie*s o!

the a!!ected &oint or oints& sedation or genera" anesthesia o! the patient to ease patient

positioning and prevent motion on the !i"m& the use o! proper !i"m and screens !or the

area o! the od% to e radiographed& and proper eposure o! the !i"m#

$t has een stated that there are t*o t%pes o! signs o! articu"ar disease: the c"inica" and

the radiographic#(25) Anima"s *ith c"inica""% ovious articu"ar disease ma% have !e*

radiographic anorma"ities& *hi"e those *ith etensive radiographic changes ma% sho*

!e* c"inica" anorma"ities# There!ore& radiograph% is ut one diagnostic too" ust

ecause a oint appears !ree o! radiographic change does not mean it is !ree o! articu"ar

disease# Fadiographic !indings must e interpreted and integrated *ith the otherdiagnostic in!ormation& especia""% *ith the !indings o! ph%sica" eamination and

s%novia" !"uid ana"%sis#

haracteristic radiographic !eatures o! DJD inc"ude sc"erosis o! suchondra" one&

suchondra" one c%sts& osteoph%te !ormation& su"uation& narro*ing o! the oint

space& and intra-articu"ar or periarticu"ar ca"ci!ication (;ig# 87-5 and 87-/)#(21)

=c"erosis o! suchondra" one is seen in more chronic cases o! DJD and suggests that

one eneath the carti"age is eing suected to increased stress that norma""% is orne

% the articu"ar carti"age# =c"erotic suchondra" one appears radiographica""% as a

homogeneous& radiodense area eneath the articu"ar sur!ace o! the a!!ected oint#
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As mentioned aove& the so-ca""ed suchondra" one c%sts o! DJD are not tru"% c%sts

ut !"uid- or mucoid !i""ed spaces in the suchondra" one proa"% created %

micro!ractures o! suchondra" traecu"ae# ecause the% "ac0 a de!inite capsu"e& these

areas are not true c%sts# Their presence in dogs and cats *ith DJD is unusua"& a"though

the% are !re4uent"% !ound in the horse and other "arge anima"s#(21) hen present& the%

appear as rounded& "ucent areas surrounded % a thin "a%er o! sc"erotic suchondra"one#

;$@# 87-5 Latera" radiographic vie* o! the e"o* o! a dog *ith DJD#

steoph%tes are seen on the crania" (1) and cauda" (2) aspects o! the oint#

=c"erosis o! the radia" head (.) and proima" u"na (3) is a"so present#

;$@# 87-/ Latera" (A) and crania"-cauda" () radiographicvie*s o! the sti!"e o! a dog *ith DJD# steoph%tes are

present on the proima" aspect o! the !emora" troch"ea (1)&

proima" and dista" aspects o! the pate""a (2)& !emora"

cond%"es (.)& and proima" tiia (3)# =c"erosis o! the

proima" tiia (5) is a"so present#

steoph%tes are common"% seen radiographica""% in more chronic cases o! DJD&

especia""% in the sti!"e& hip& shou"der& and e"o* oints# The% appear as periarticu"ar

spurs or outgro*ths o! one arising !rom the margins o! the articu"ar sur!ace#

orre"ations have not een made et*een the presence o! osteoph%tes and the presenceo! articu"ar carti"age rea0do*n or disease# $n other *ords& does the radiographic

!inding o! osteoph%te !ormation automatica""% mean the presence o! DJDH hi"e it is

true that osteoph%tes are common in oints a!!ected *ith DJD& &oints that have

osteoph%tes ma% not have the other !eatures o! DJD#(23) To date& this controvers% has

not een reso"ved# $t is sa!e to sa% that osteoph%tes a"one proa"% are not

pathognomonic o! DJD ut their presence does indicate some anorma" activit% *ithin

or adacent to the a!!ected oint#

=u"uation has een descried as a radiographic !eature o! DJD o! the sti!"e o! the dog#

(2) A"though proa"% due more to concomitant "igamentous andGor menisca" inur%

than to an%thing e"se& the su"uation is demonstra"e in man% cases *hen theradiographs are ta0en *ith the patient in a *eight-earing position# Anorma" oint

"ait% due to the "oss o! supporting structures p"a%s a signi!icant ro"e in the perpetuation

o! DJD# The anorma" stresses to *hich the oint tissues are suected ecause o!

supporting structure "oss continua""% !eed the !ire o! in!"ammation& resu"ting in oint

tissue destruction# hether the "ait% preceded the degenerative changes and there!ore

resu"ted in secondar% DJD or *hether the "ait% occurred as a resu"t o! the "igamentous

destruction in the ongoing process o! primar% DJD is& at "east !or this discussion&

immateria"# hat is important is that su"uation can e seen radiographica""% in DJD#

$n the hip it is o!ten seen in the DJD o! hip d%sp"asia#

Joint "ait% ma% a"so e demonstrated radiographica""% % otaining >stress> vie*s o!

the a!!ected oint# =tress vie*s are otained % app"%ing anorma" media" or "atera"
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pressure to a oint that is eing radiographed# Li0e*ise& the oint ma% e radiographed

in h%per!"eion or h%peretension#

hanges in radiographic appearance o! the oint space in DJD or other articu"ar diseases

must e udged and interpreted *ith care# ?arro*ing or co""apse o! the oint space is

said to e a !air"% consistent !eature o! chronic DJD#(21) This is due to the "oss o!signi!icant amounts o! articu"ar carti"age& a""o*ing suchondra" one& *hich is more

radiodense than articu"ar carti"age& to come in c"oser contact& there!ore giving the

appearance o! a narro* oint space# This in !act is the case& ut the radiographic

appearance o! the oint space *i"" a"so e a!!ected % patient positioning& assumption o!

a *eight-earing or non-*eight-earing position *hen the radiograph *as ta0en& oint

e!!usion& and integrit% o! the "igamentous structures o! the a!!ected oint# As noted

aove& dogs *ith hip d%sp"asia and DJD o! the coo!emora" oint have oint e!!usion

that a!!ects the inter!ace et*een the !emora" head and the acetau"um#("2&1.) $n these

anima"s the oint space *i"" appear 4uite di!!erent i! radiographs are ta0en e!ore and

a!ter arthrocentesis# True assessment o! changes in the *idth o! the oint space are est

made *ith the patient in a *eight-earing position#

a"ci!ication o! the supporting so!t tissues o! a oint& *hether intra-articu"ar or

periarticu"ar& is rare"% seen in the dog# This !inding has een associated *ith DJD o!

"ong duration# 6o*ever& so!t tissue ca"ci!ication a"one& *ithout other radiographic signs&

is proa"% a poor indication o! the presence o! DJD#(21) =%novia" chondromatosis is a

condition in *hich chondri!ication and minera"i+ation o! the s%novia" memrane occur#

A"though rare in the dog& the patient presents *ith "ameness and minera"i+ed densities

*ithin the oint# The etio"og% o! the condition is un0no*n in humans and in dogs& and

the oint in!"ammation that ensues is secondar% to the origina" pro"em#

$ntra-articu"ar minera"i+ation can a"so e seen *ith osteochondritis dissecans# Loose

odies !orm !rom the dis"odged carti"aginous !"ap# The carti"age is nurtured % the

s%novia" !"uid and remains via"e# $n some cases the !ree !"ap ecomes emedded in the

s%novia" memrane# nce again& this unusua" !inding is not characteristic o! DJD it is

ust an odd !inding in the occasiona" case o! osteochondritis dissecans#

Clinical a*oratory !in&ings

There are no speci!ic "aorator% !indings characteristic o! DJD# Fesu"ts o! a hemogram&urina"%sis& and "ood chemistr% determinations are usua""% *ithin norma" "imits# Fesu"ts

o! rheumatoid !actor tests and "upus er%thematosus (L) c"ot tests are negative& as is the

search !or antinuc"ear antiodies#

amination o! the s%novia" !"uid *i"" usua""% con!irm the presence o! a "o*-grade

intra-articu"ar in!"ammator% processes in the acute condition or in secondar% DJD

associated *ith common conditions such as osteochondritis dissecans& hip d%sp"asia& or

ruptured crania" cruciate "igament& s%novia" !"uid vo"ume is o!ten increased# =%novia"

!"uid co"or ranges !rom pa"e %e""o* to stra* co"or and is usua""% c"ear# 6a+iness or

!"occu"ence ma% e seen in some cases o! secondar% DJD& especia""% those in *hich

there is an articu"ar carti"age de!ect# Ciscosit% is usua""% norma" and the mucin c"ot testrated !"air to good#
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Tota" *hite ce"" count rare"% eceeds 5 ce""sG mm. the predominant ce""s are

"%mphoc%tes and monoc%te-macrophages# ,hagoc%tic vacuo"es ma% e seen on c"ose

eamination o! the macrophages# ?eutrophi"s are rare"% encountered#

"reat)ent

steoarthritis is not a condition that can e cured in the sense o! returning the patient to

comp"ete norma"c%# $n most cases& some residua" anorma"it% *i"" remain in the

a!!ected oint or oints& and this anorma"it% is o!ten o! such a nature as to continua""%

produce di!!icu"ties !or the patient# The goa"s in the treatment o! DJD are to a""eviate the

anima"


16/27

shou"d increase in "ength# 'ore strenuous activities can e introduced as the anima"

gains strength#

hi"e the re"ationship et*een oesit%per seand DJD in humans remains

controversia"& reduction to idea" *eight appears prudent& since degenerative changes are

initiated or aggravated % ecessive or anorma""% directed pressures on articu"arcarti"age#(22) eight reduction % dietar% contro" shou"d e considered !or the

over*eight dog as *e""# This is o!ten di!!icu"t to accomp"ish o*ing to the re"uctance o!

o*ners to !eed their anima"s "ess and o*ing to the "imited activit% o! the patient# a"oric

re4uirements shou"d e ca"cu"ated !or the anima" ased on idea" od% *eight and

amount o! activit% a dietar% p"an can then e esta"ished !or the o*ner to !o""o*#

DR#G "HERAP$

There are no drugs or cominations o! drugs that *i"" consistent"% prevent or reverse the

patho"ogic changes o! DJD# Drugs are administered to DJD patients primari"% as

ana"gesics and anti-in!"ammatories !or s%mptomatic re"ie! o! c"inica" signs#

As'irin

Acet%"sa"ic%"ic acid (aspirin) is an ana"gesic and anti-in!"ammator% as *e"" as an

antip%retic and is the asic drug !or the treatment o! DJD# $t is the asic drug in a c"ass

0no*n as nonsteroida" anti-in!"ammator% agents# Used proper"% it can e 4uite e!!ective

and !ree o! side-e!!ects# Aspirin has an impact on a *ide variet% o! metao"ic processes

and en+%me s%stems# 'i"d to moderate periphera" pain is re"ieved % its ai"it% to "oc0

the e!!ects on pain endings o! in!"ammator% mediators such as rad%0inin#(2)$n contrast

to the opiates& aspirin acts periphera""% rather than centra""% as an ana"gesic# Aspirin


17/27

Phenyl*+ta,one

,hen%"uta+one has een used *ith a good dea" o! success in the s%mptomatic treatment

o! chronic DJD# $t has een 4uite va"ua"e in some cases o! DJD that *ere unresponsive

to aspirin# ecause o! the one marro* depression it ma% cause& phen%"uta+one has noteen used as *ide"% in humans as it has in anima"s# hen proper"% administered and

monitored& it can e a most va"ua"e drug !or the s%mptomatic treatment o! DJD in the

dog#

,hen%"uta+one is a nonsteroida" anti-in!"ammator% drug *ith a mechanism o! action

simi"ar to that o! aspirin#(.5) $t is given in dosages ranging !rom #5 mg to 1# mgG0g o!

od% *eight three times per da%# one marro* depression ma% e the most serious o!

its side-e!!ects# ,eptic u"cers& ma"aise& pruritus& rashes& rena" d%s!unction& and other

pro"ems have a"so een reported in humans#

Other Nonsteroi&al Anti-in.la))atory Agents

ithin recent %ears a variet% o! agents have een introduced !or treatment o! articu"ar

disease# There is a categor% o! nonsteroida" anti-in!"ammator% agents that are common"%

re!erred to as aspirin-"i0e# These drugs a"so are anti-in!"ammator%& ana"gesic& and

antip%retic& and their mode o! action is the inhiition o! prostag"andin s%nthesis or

re"ease# The drugs o! this t%pe present"% approved in the United =tates !or use in

humans inc"ude !enopro!en& iupro!en& indomethacin& ne!anamic acid& naproen&

o%phen%"uta+one& su"indac& and to"metin#(2.) 'ec"o!enamic acid has een approved

!or use in the horse# The e!!icac% o! man% o! these drugs in the dog has %et to e

esta"ished# n a c"inica" asis& mec"o!enamic acid has een as e!!ective as aspirin in

some cases o! DJD in the dog#I

$upro!en given ora""% in a tota" dose o! 15 mgG0g od% *eight divided into three doses

dai"% and indomethacin in an ora" dose o! 1# mg to 1#25 mgG0g divided into t*o or

three doses dai"% have een suggested !or the treatment o! DJD in the dog#(28) ith

chronic use oth drugs ma% cause gastrointestina" pro"ems#

To date& there is "itt"e convincing data that sho* that an% o! the ne*er compounds are

superior to aspirin in e!!ectiveness *hen the oective o! therap% is an immediate anti-

in!"ammator% e!!ect#(33) The compounds do& ho*ever& have !e*er side-e!!ects& and !or

that reason a"one have !ound great acceptance % the ph%sician and the genera" pu"ic#e""-designed and *e""-eecuted studies *i"" e needed e!ore their e!!ectiveness in the

dog and the cat can e determined#

$t is important to note that as o! this *riting man% o! these ne*er drugs have not een

approved % the appropriate authorities !or use in the dog# There!ore& one cannot "ega""%

administer or prescrie them#

I a""ace LJ: Unpu"ished data

Corticosteroi&s

orticosteroids are potent anti-in!"ammator% drugs that ma% e o! ene!it in some cases
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o! DJD# Their mechanism o! action is re"ated to retardation o! "eu0oc%te migration&

decreased permeai"it% o! microvascu"ature& inhiition o! prostag"andin re"ease& and

stai"i+ation o! $%sosoma" memranes# (7&.5) orticosteroids shou"d not e considered

as the agent o! choice in the treatment o! DJD# The% are reserved !or those cases that are

unresponsive or s"o*"% responsive to the previous"% mentioned agents# orticosteroids

are most common"% administered ora""% or parentera""% in "o* doses and given !or shortperiods o! time# ,redniso"one ma% e given parentera""% at a dose o! " mg to 2 mgG0g

!o""o*ed % an ora" maintenance dose o! #5 to 1# mgG0g once dai"%# The "o*est

possi"e maintenance dose shou"d e esta"ished& such as a"ternate da% or ever% third

da% administration o! #5 mg to 1# mgG0g# orticosteroids have een used in

comination *ith nonsteroida" anti-in!"ammator% drugs# Aspirin and corticosteroids are

administered concomitant"% in the doses mentioned aove# ach suse4uent da%&

sma""er doses are given so that % the !i!th or sith da% corticosteroids are no "onger

administered and the aspirin is eing given in "o* maintenance doses# hi"e some

patients respond to this regime& the% ma% e prone to gastrointestina" hemorrhage#

$ntra-articu"ar insti""ation o! corticosteroids has een used in humans and in anima"s !orthe treatment o! DJD# !!ects o! the drug "ast !or var%ing periods o! time and are o!ten

repeated on an >as needed> asis# $t has een suggested that the ene!icia" e!!ects o!

such treatment are due to asorption and s%stemic distriution o! the drug#(22) The

practice o! intra-articu"ar corticosteroid inection is not *ithout comp"ications#

,ostinection !"are& a s%novitis induced % corticosteroid cr%sta"s& ma% occur# $n

addition& the inected oint ma% e more suscepti"e to in!ection# perimenta" *or0 in

anima"s and c"inica" oservations in humans sho* that intra-articu"ar corticosteroids

have a de"eterious e!!ect on carti"age that is a"read% damaged % disease#(22) To date&

su!!icient studies in the dog and cat have not een recorded that con!irm or den% that

these anima"s are as suscepti"e or as prone to the comp"ications o! intra-articu"ar

corticosteroids as are humans# $ntra-articu"ar corticosteroids in the dog and cat shou"d

e used *ith great discretion unti" such in!ormation is avai"a"e#

Other Dr+gs

$ntra-articu"ar inection o! h%a"uronic acid is present"% under investigation as a treatment

!or DJD in humans and in anima"s# A hea"ing e!!ect on traumatic "ameness in the horse

has een reported# (..) 6o*ever& c"inica" tria"s in human osteoarthritic 0nee oints have

so !ar sho*n either no ene!icia" e!!ect or var%ing degrees o! improvement o!

s%mptoms#(22) Unti" !urther reports are avai"a"e& this drug shou"d proa"% not e

considered a part o! the treatment regime !or DJD#

rgotein is another drug that ma% have potentia" in the treatment o! DJD to date it has

not een studied in su!!icient depth or "ength to e recommended# rgotein is a

superoide dismutase that eerts its e!!ects % memrane stai"i+ation& promotion o!

"eu0oc%te chemotais& and& most important"%& % inhiition o! certain en+%me !unctions

that promote in!"ammation#(.5)

$nection into osteoarthritic hips and 0nees o! humans produced sustained improvement&

and such treatment has een used in the horse *ith some success# (22&.5)

AC#P#NC"#RE
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Acupuncture has een sho*n to e e!!ective in the reduction o! certain t%pes o! pain#

6o*ever& reports o! its e!!icac% in humans *ith DJD are con!"icting#(22) hi"e it ma%

e o! some ene!it in anima"s *ith DJD& contro""ed studies are "ac0ing# Unti" such

reports are avai"a"e# acupuncture *i"" remain a controversia" and curious phenomenon#

S#RGER$

The main purposes o! surger% in the treatment o! DJD are to increase oint !unction and

reduce or e"iminate oint pain# The t*o ma% not e compati"e# ;or instance& arthrodesis

is done most common"% to reduce oint pain and return a "im to use& ut ovious"% the

a!!ected oint *i"" no "onger e !unctiona"# The maorit% o! sma"" anima"s *ho are

operated upon !or oint disease have secondar% osteoarthritis# steochondritis dissecans

o! the shou"der and ruptured crania" cruciate "igament o! the sti!"e are good eamp"es#

ach condition& especia""% i! it is o! severa" *ee0s duration& is a"most a"*a%s associated

*ith changes o! secondar% DJD# % appropriate surgica" treatment o! each& the primar%

condition is e"iminated& thus ending the cause o! the secondar% DJD#

rthopaedic procedures re"ated to oint disease ma% e categori+ed as articu"ar& uta-

articu"ar (immediate"% adacent to the oint)& and para-articu"ar (near a oint)#(8)

Artic+lar

=%novectom%& the surgica" remova" o! s%novia" memrane& is usua""% per!ormed in

cases o! immune-mediated arthritis such as rheumatoid arthritis# Femova" o! the active

pro"i!erative s%novium o!ten causes remission o! s%mptoms and return to !unction !or

"ong periods o! time# $t is not a procedure recommended !or DJD# ;usion o! a oint& or

arthrodesis& as noted aove& is used to stai"i+e a severe"% pain!u" andGor de!ormed oint

in hopes o! increasing use o! the entire "im# $n the dog& the carpus& hoc0& and sti!"e are

the oints !used most !re4uent"%# n rare occasions& the e"o* and shou"der ma% a"so e

arthrodesed#(31)

Arthrop"ast% is reui"ding a oint and inc"udes the insertion o! a tota" prosthesis& as is

done !or the severe DJD o! hip d%sp"asia& or a troch"eop"ast% o! the dista" !emur !or

pate""ar "uation# Fesection arthrop"ast% is reui"ding % removing the adacent ends o!

one ma0ing up the oint and a""o*ing a pseudoarthrosis to deve"op# This is the

rationa"e !or !emora" head and nec0 ecision in cases o! severe hip d%sp"asia#

ther eamp"es o! resection arthrop"ast% in the treatment o! conditions resu"ting insecondar% DJD inc"ude remova" o! ununited (!ragmented) coronoid and ununited

anconea" processes !rom the e"o* oint#

J+(ta-artic+lar

=urger% ma% e per!ormed on structures net to rather than direct"% inside a oint#

apsu"orrhaph% procedures !or pate""ar "uation or etracapsu"ar stai"i+ation

techni4ues o! the sti!"e !or anterior cruciate "igament rupture are eamp"es#

Para-artic+lar

steotom% is a surgica""% induced !racture that a""o*s a then rea"igned one to hea" so
http://www.ivis.org/special_books/ortho/chapter_87/87mast.asp#refs%23refshttp://www.ivis.org/special_books/ortho/chapter_87/87mast.asp#refs%23refshttp://www.ivis.org/special_books/ortho/chapter_87/87mast.asp#refs%23refshttp://www.ivis.org/special_books/ortho/chapter_87/87mast.asp#refs%23refshttp://www.ivis.org/special_books/ortho/chapter_87/87mast.asp#refs%23refshttp://www.ivis.org/special_books/ortho/chapter_87/87mast.asp#refs%23refs


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that di!!erent !orces are imparted to the adacent oints# steotomies are done to correct

dista" radia" and u"nar gro*th de!ormities& *hich i! uncorrected ma% "ead to DJD o! the

carpus and e"o* oints# ,e"vic osteotomies are no* per!ormed in se"ected cases o! hip

d%sp"asia to prevent !urther degenerative changes !rom occurring in the coo!emora"

oint#

Tendon surger% ma% e o! ene!it in certain cases o! DJD# Transsection o! the pectineus

musc"e is used in se"ect cases o! hip d%sp"asia to reduce pain in the a!!ected oint#

$t must e rememered that the surgica" procedures mentioned here are not meant to e

speci!ic treatments o! DJD# Father the% are part o! a treatment p"an designed to decrease

pain and increase oint and "im !unction#

The treatment o! primar% and secondar% DAD is essentia""% the same ecept that the

initiating cause o! secondar% DJD must e treated as *e""# ontro""ed eercise and

ph%siotherap% are important to the anima"


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1# o""et AJ: An essa% on the io"og% o! osteoarthritis# Arthritis Fheum 12: 152& 19/9

2# Davis L: "inica" pharmaco"og% o! sa"ic%"ates# J Am Cet 'ed Assoc 17/:/5& 198

.# hr"ich '@& 'an0in 6J& Tread*e"" C: Acid h%dro"ase activit% in osteoarthritis andnorma" human carti"age# J one Joint =urg 55A: 1/8& 197.

3# @ardner DL: @enera" patho"og% o! the periphera" oints# $n =o0o"o!! L (ed): The

Joints and =%novia" ;"uid& vo" 2# ?e* or0& Academic ,ress& 198

5# @hosh ,: L%sosoma" en+%mes in oint disease# Aust ? J 'ed 8: 12& 1978

/# @i"ertson '': Deve"opment o! periarticu"ar osteoph%tes in eperimenta""%

induced osteoarthritis in the dog# Ann Fheum Dis .3:12& 1975

7# Kantor T@: Anti-in!"ammator% and ana"gesic drugs# $n Kat+ A (ed): FheumaticDiseases# ,hi"ade"phia& J Lippincott& 1977

8# Kau!!man '=: Arthritis surger%# $n Kat+ A (ed): Fheumatic Diseases#

,hi"ade"phia& J Lippincott& 1977

9# Langens0io"d A& 'iche"sson J# Cideman T: steoarthritis o! the 0nee in the rait

produced % immoi"i+ation# Acta rthop =cand 5: 1& 1979

1# Leach D& =umner-=mith @# Dagg AJ: Diagnosis o! "ameness in dogs: A pre"iminar%

stud%# an Cet J 18:58& 1977

11# Lippie""o L& 6a"" D& 'an0in 6&J: o""agen s%nthesis in norma" and osteoarthritic

human carti"age# #$ "in $nvest 59:59.& 1977

12# Lust @# ei"man T& endano CT: A re"ationship et*een degree o! "ait% and

s%novia" !"uid vo"ume in coo!emora" oints o! dogs predisposed !or hip d%sp"asia# Am J

Cet Fes 31: 55& 198

1.# Lust @# ei"man T& Due"and DJ et a": $ntra-articu"ar vo"ume and hip oint

instai"it% in dogs *ith hip d%sp"asia# J one oint =urg /2A:57/& 198

13# Lust @# ,rons0% # =herman D': iochemica" and u"trastructura" oservation in

norma" and degenerative canine articu"ar carti"age# Am J Cet Fes ..:2329& 1972

15# 'cart% DJ: Di!!erentia" diagnosis o! arthritis: Ana"%sis o! signs and s%mptoms# $n

'cart% DJ (ed): Arthritis and A""ied onditions# ,hi"ade"phia& Lea E ;eiger& 1979

1/# 'cDevitt & @i"ertson & 'uir 6: An eperimenta" mode" o! osteoarthritis: ar"%

morpho"ogica" and iochemica" changes# #$ one Joint =urg 59:23& 1977

17# 'cDevitt LA& 'uir 6: iochemica" changes in the carti"age o! the 0nee in

eperimenta" and natura" osteoarthritis in the dog# #$ one Joint =urg 58:93& 197/


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18# 'an0in 6J: The reaction o! articu"ar carti"age to inur% and osteoarthritis# ? ng" J

'ed 291:1285& 1973

19# 'inor FF: o""agen metao"ism# Am J ,atho" 98: 227& 198

2# 'organ J,: Fadio"ogica" patho"og% and diagnosis o! degenerative oint disease inthe sti!"e oint o! the dog# J =ma"" Anim ,ract 1:531& 19/9

21# 'organ J,: Fadio"og% in Ceterinar% rthopedics& pp 185-18/# ,hi"ade"phia& Lea E

;eiger& 1972

22# 'os0o*it+ F: Treatment o!< osteoarthritis# $n 'cart% DJ (ed): Arthritis and

A""ied onditions& 9th ed# ,hi"ade"phia& Lea E ;eiger& 1979

2.# ?ic0ander F# 'c'ahon ;@& Fido"!o A=: ?onsteroida" anti-in!"ammator% agents#

Ann Fev ,harmaco" Toico" 19:3/9& 1979

23# "sson =: Degenerative oint disease (osteoarthrosis): A revie* *ith specia"

re!erence to the dog# J =ma"" Anim ,ract 12: ...& 1971

25# *ens J'& Ac0erman ?: Foentgeno"og% o! arthritis# Cet "in ?orth Am 8:35.&

1978

2/# ,a"mos0i 'J& o"%er FA& randt KD: Joint motion in the asence o! norma" "oading

does not maintain norma" articu"ar carti"age# Arthritis Fheum 2.:.25& 198

27# ,eacoc0 Jr& Can in0"e Jr: ound Fepair& 2nd ed& pp 82-83# ,hi"ade"phia&

=aunders& 197/

28# ,ederson ?& ,oo" F: anine oint disease# Cet "in ?orth Am 8:3/5& 1978

29# ,ederson ?& eisner K& ast"es JJ et a": ?onin!ectious canine arthritis: The

in!"ammator% nonerosive arthritides# J Am Cet 'ed Assoc 1/9:.3& 197/

.# ,erman C: =%novia" !"uid# $n Kane0o J (ed): "inica" iochemistr% o! Domestic

Anima"s& .rd ed# ?e* or0& Academic ,ress& 198

.1# ,roc0op DJ& Kiviri00a K$& Tuderman L et a": The ios%nthesis o! co""agen and itsdisorders# ? ng J 'ed .1: 1.& 77& 1979

.2# Fo% ;: amination o! the canine "ocomotor s%stem# Cet "in ?orth Am 1:5.&

1971

..# F%de"" ?& ut"er J# a"a+s A: 6%a"uronic acid in s%novia" !"uid: C$# !!ect o!

intra-articu"ar inection o! h%a"uronic acid on the c"inica" s%mptoms o! arthritis in trac0

horses# Acta Cet =cand $ 1:1.9& 197

.3# =ch*art+ F: 'etao"ic response during ear"% stages o! surgica""% induced

osteoarthritis in mature eag"es# J Fheumato" 7:788& 198


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.5# =hort F& ead"e F: ,harmaco"og% o! antiarthritic drugs# Cet "in ?orth Am

8:31& 1978

./# =o0o"o!! L: The io"og% o! Degenerative Joint Disease# hicago& Universit% o!

hicago ,ress& 19/9

.7# =oren A: 6istodiagnosis and "inica" orre"ation# Fheumatoid and ther =%novitis#

,hi"ade"phia& #$ Lippincott 1978

.8# =tephens F& @hosh ,# Ta%"or TK;: The pathogenesis o! osteoarthritis# 'ed

6%potheses 5:89# 1979

.9# =*eet '& Thomas J'A& $mme"man AF et a": iochemica" changes in

progressive osteoarthritis# Ann Fheum Dis ./:.87& 1977

3# Thompson F Jr& egema TF: 'etao"ic activit% o! articu"ar carti"age in

osteoarthritis# J one Joint =urg /1A:37& 1979

31# Turner T# Lipo*it+ AJ: Arthrodesis# $n ora 'J (ed): urrent Techni4ues in

=ma"" Anima" =urger% $$# ,hi"ade"phia& Lea E ;eiger& 198.

32# Caden ';& ,urohit F& 'co% 'D et a": Thermograph%: A techni4ue !or

suc"inica" diagnosis o! osteoarthritis# Am &J Cet Fes 31: 1175& 198

3.# eiss : ?orma" and osteoarthritis articu"ar carti"age# rthop "in ?orth Am

1:175& 1979

33# i"0ens F;: The use o! nonsteroida" anti-in!"ammator% agents# J Am 'ed Assoc

23:1/.2& 1978

35# i"terger 6# Lust @: U"trastructure o! canine articu"ar carti"age: omparison o!

norma" and degenerative (osteoarthritis) hip oints# Am J Cet Fes ./:727& 1975

3/# ong ,L& Lipo*it+ A&J& =tevens J: =%novia" memrane changes a!ter

eperimenta" transection o! the anterior cruciate "igament in dogs# Am J Cet Fes (in

press)

37# ear"% FA& rant FJ: Aspirin dosages !or the dog# J Am Cet 'ed Assoc 1/7:/.&1975

http:GG***#at"antae4uine#comGpagesGc"ient"idegeneratJointD#htm"

Enfermedad comn degenerativa (DJD)

La enfermedad comn degenerativa (DJD), designada a menudo osteoartritis, es una causamu! comn de" "ameness en ca#a""os de" funcionamiento. La ma!or$a de "as estrategiase%uinas de" entrenamiento imp"ican "a prevenci&n !'o e" mantenimiento de una cierta forma deenfermedad comn. La carencia de" funcionamiento como resu"tado de "a enfermedad comnprecede a menudo "ameness a#ierto !'o cam#ios radiogrficos.

Cuntos diversos tipos de empalmes hay?a! 3 tipos deempa"mes %ue se c"asifi%uensegn su gama de" movimiento. Los Synarthrosesson empa"mes inmue#"es. Los


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Amphiarthrosesse mueven "evemente. Los Diart*roses son empa"mes movi#"es. La ma!orparte de "os empa"mes en e" miem#ro e%uino son diart*rodia" en natura"eza ! son genera"mente"os %ue nos asociamos a "ameness e%uino. Los empa"mes de Diart*rodia" por "o tanto serndescritos con e" fin de esta discusi&n.

Qu estructuras componen un empalme?+" empa"me s!novia" o diart*rodia" consiste en

superficies de articu"aci&n de" *ueso (""amado *ueso su#c*ondra")

capa de" cart$"ago (%ue cu#re e" *ueso su#c*ondra")

una cpsu"a comn fi#rosa

s!novium (mem#rana ! "$%uido s!novia" %ue consisten en)

"igamentos de soporte asociados

La com#inaci&n de una superficie "isa ! de un "$%uido s!novia" grueso de" cart$"ago proporcionaun am#iente de "a #a-ofricci&n a trav/s de e" cua" "as superficies de articu"aci&n puedanmoverse "i#remente e independientemente de uno a.

Qu hace el l!"uido synovial tan grueso y desli#adi#o?Dentro de mem#rana ! de "$%uidos!novia" est una mo"/cu"a grande ""amada *!a"uronan. Hyaluronanes e" componente primariode" "$%uido s!novia" %ue te da sus caracter$sticas gruesas ! des"izadizas. 0uesto %ue "a fricci&nde reducci&n a" m$nimo es cr$tica a "a funci&n comn norma", "a presencia de *!a"uronan norma"dentro de un empa"me es mu! importante. La carencia de *!a"uronan dentro de" "$%uidos!novia" aumenta "a fricci&n asociada a "a mem#rana s!novia" ! a "as superficies articu"ares, por"o tanto predisponiendo e" cart$"ago a" desgaste ! a "a erosi&n e1cesivos.

Qu causa la inflamaci$n comn (artritis)?La inf"amaci&n comn es una consecuencia delesin!'o de "a inestabilidadcomunes. La inesta#i"idad puede ocurrir como resu"tado de"compromiso de "as estructuras de soporte de" empa"me (ta"es como "os "igamentos co"atera"es),de "a p/rdida de cart$"ago articu"ar (como puede ocurrir en osteoc*ondrosis), de" overuse, !'ode "a edad creciente.

Qu causa dolor comn?La ma!or$a de "os conc"usiones de nervio miente dentro de "acpsula fibrosa! de "os ligamentos de soporte delempa"me. a! sensi#i"idad mu! pe%ue2a ene" cart$"ago ! e" s!novium.

Las tres causas primarias de" do"or comn, por "o tanto, estn


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1# +fusi&n comn (es decir "$%uido creciente dentro de" empa"me) dando por resu"tado "adistenci&n %ue estira de "a cpsu"a comn,

2# 3i#rosis'e" marcar con una cicatriz de "a cpsu"a comn (designada a menudocapsu"itis), !

.# 4nf"amaci&n dentro de "os "igamentos de soporte asociados de" comn (""amadodesmitis)

+"iminando e1ceso de "$%uido s!novia", "a inf"amaci&n dentro de "a cpsu"a fi#rosa, ! "ainf"amaci&n dentro de "os "igamentos de soporte producirn genera"mente un empa"me c&modo.

C$mo la enfermedad comn degenerativa (DJD) ocurre?+" cic"o degenerativo se iniciacomo resu"tado de inesta#i"idad !'o de "esi&n comunes. La inf"amaci&n de "a mem#ranas!novia" (una condici&n ""amada synovitis) ocurre secundario para articu"ar inesta#i"idad'trauma.

Las c/"u"as inf"amatorias dentro de "a mem#rana ! de" "$%uido s!novia" *acen dos cosas

1# 5u presencia aumenta "a presi&n *idrosttica dentro de" empa"me !

2# Lanzan a "as enzimas cata#&"icas ("!soz!mes) ! a otros mediadores %u$micos en e"empa"me.

La presi&n *idrosttica creciente da "ugar a "a af"uencia de" "$%uido en e" empa"me (efusi&ns!novia"), "a distenci&n (estirando) de "a cpsu"a comn, ! e" do"or. Las enzimas "anzaron por"as c/"u"as inf"amatorias degradan *!a"uronan ("a mo"/cu"a %ue est imp"icada en "a "u#ricaci&nnorma" de" empa"me) as$ como "a capa de" cart$"ago. +" compromiso ! "a erosi&n eventua" de"cart$"ago acodan resu"tados en p/rdida de congruenc! articu"ar, %ue a"ternadamente aumentainesta#i"idad comn.

4nteresante, "a presencia de" do"or tam#i/n acenta "a actividad'e" "anzamiento de "osmediadores de" producto %u$mico da2oso en e" empa"me. 4nesta#i"idad comn creciente, "apersistencia de mediadores %u$micos dentro de" empa"me, ! resu"tado de" do"or en una

reacci&n inf"amatoria creciente.

6 e" cic"o comienza7


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C$mo tratamos DJD?

0ara %ue "a estrategia de" tratamiento sea acertada, /" de#a centrarse en e" siguiente

8a1imizaci&n de esta#i"idad comn

9rauma de reducci&n a" m$nimo a" empa"me 5!novitis de reducci&n a" m$nimo (inf"amaci&n comn)

+fusi&n s!novia" de reducci&n a" m$nimo ("$%uido comn e1cesivo) 3i#rosis de reducci&n a" m$nimo de "a cpsu"a comn (%ue ocurre como resu"tado de "a

inf"amaci&n cr&nica) Norma"izando e" am#iente comn (es decir ma1imizando "a cantidad de *!a"uronan

norma" dentro de" s!novium) Do"or de reducci&n a" m$nimo

Actua"mente, no tenemos ninguna manera eficaz de esta#i"izar "a ma!or$a de "os empa"mesdiart*rodia" sin e" compromiso de su funci&n ! gama de" movimiento. Disminuir e" desaf$o (esdecir e" grado de "a e1tensi&n'de "a f"e1i&n) a "os empa"mes se puede a"canzar a menudo con

ca"zar correctivo, no o#stante persistir un cierto grado de inesta#i"idad genera"mente. Lacirug$a puede ser eficaz en me-orar esta#i"idad comn ! disminuir trauma en "os casos %ueimp"ican "esiones ortop/dicas de desarro""o (ta"es como osteoc*ondrosis, :CD, %uistessu#c*ondra") ! a"gunos tipos de fracturas.

0ara "a ma!or parte, sin em#argo, de#emos confiar en "as terapias dise2adas para reducir "ainf"amaci&n ! para do"er ! para norma"izar "os am#ientes s!novia" como me-or es posi#"e. +stasmedicaciones se refieren como art*rot*erap!, e inc"u!en formas systemic! locales.

Cul es arthrotherapy %&%'EC?Cua"%uier medicaci&n administrada fuera de" empa"me(por via ora", intravenoso, o intramuscu"ar por e-emp"o) con e" fin de me-orar "a funci&n !'o "acomodidad comunes se considera una forma de art*rot*erap! s!stemic. Las medicacionesantiinf"amatorias (ta"es como p*en!"#utazone), a"gunos mitigadores de" do"or (ta"es comocapsaicin), ! "os sup"ementos de" empa"me (ta"es como Ade%uan;, Legend;, ! Cose%uin;) seinc"u!en en esta categor$a. Los sup"ementos de" empa"me *an considerado uso amp"io estos"timos a2os, ! son "o ms a menudo posi#"e "a primera "$nea de" c"iente de" tratamiento paraDJD en sus ca#a""os. La meta fundamenta" de" sup"emento comn es estimu"ar actividadnorma" ! "a funci&n de "a mem#rana s!novia" de ta" modo %ue rea"za "a integridad de" am#ientecomn. Las formas ora"es, intravenosas, e intramuscu"ares e1isten.

La ma!or$a de "os estudios demuestran %ue "as medicaciones ora"es (e.g. Cose%uin;, 858,f"e1i&n 3ree;, Cortaf"e1;, etc.) son a#so"utamente eficaces cuando estn a#sor#idas en e"sistema. +ste tipo de tra#a-os art*rot*erap! especia"mente #ien en "a gente ! "os perros, %uepueden a#sor#er "as mo"/cu"as re"ativamente grandes (como e" su"fato de" g"ucosamine ! de"c*ondroitin) a trav/s de su pared intestina" fci"mente. Los ca#a""os, por otra parte, no son

genera"mente peritos en a#sor#er "as mo"/cu"as grandes en su sistema de "a zona intestina".0or "o tanto, una porci&n de "a medicaci&n ora" (! de "a inversi&n de" c"iente) no puede seruti"izada tota"mente. 8uc*as compa2$as estn tra#a-ando continuamente para encontrarmaneras de me-orar e" a#sor#a#i"it! de sup"ementos ora"es en e" ca#a""o.

Las medicaciones %ue puentean "a zona intestina" de ca#a""os (! por "o tanto no co

Documents

Degenerative Joint Disease and Traumatic Arthritis