JOINT PATHOLOGYJOINT PATHOLOGY

CONTENTSCONTENTS

ARTHRITISARTHRITIS OSTEOARTHRITISOSTEOARTHRITIS GOUT AND PSEUDOGOUTGOUT AND PSEUDOGOUT INFECTIOUS ARTHRITISINFECTIOUS ARTHRITIS LYMES ARTHRITISLYMES ARTHRITIS

TUMORSTUMORS CANGLION AND SYNOVIAL CYSTSCANGLION AND SYNOVIAL CYSTS PVNS AND GCT OF TENDON PVNS AND GCT OF TENDON

SHEATHSHEATH

OsteoarthritisOsteoarthritis

Primary degenerative disorder Primary degenerative disorder of articular cartilageof articular cartilage

Age Age 65 or more65 or more

TypesTypes PrimaryPrimary

Oligoarticular and in older peopleOligoarticular and in older people

SecondarySecondary YouthYouth Traumatic, developmental deformity, Traumatic, developmental deformity,

underlying systemic disease like underlying systemic disease like diabetes, ochronosis, diabetes, ochronosis, hemochromatosis, obesityhemochromatosis, obesity

May be poly articular and has gender May be poly articular and has gender differencesdifferences

Knees and hands- womenKnees and hands- women Hips- menHips- men

MorphologyMorphology Enlargement, proliferation and Enlargement, proliferation and

disorganization of chondrocytes in disorganization of chondrocytes in superficial part of articular cartilagesuperficial part of articular cartilage

Vertical and horizontal fibrillatioon and Vertical and horizontal fibrillatioon and cracking of matrixcracking of matrix

Degradation of superficial layersDegradation of superficial layers Soft granular articular cartilage surfaceSoft granular articular cartilage surface Sub chondral bone plates are exposed Sub chondral bone plates are exposed

and appearance of polished ivory (bone and appearance of polished ivory (bone eburnation) Underlying cancellous bone eburnation) Underlying cancellous bone becomes sclerotic and thickenedbecomes sclerotic and thickened

Small fractures dislodge pieces of Small fractures dislodge pieces of cartilage and subchondral bone- joint cartilage and subchondral bone- joint micemice

Synovial fluid forced to subchondral Synovial fluid forced to subchondral region- fibrous walled cystsregion- fibrous walled cysts

Mushroom shaped osteophytes at Mushroom shaped osteophytes at margins of articular surface margins of articular surface

Fibrous synovial pannus covers Fibrous synovial pannus covers peripheral portionsperipheral portions

Cartilage has more water and less Cartilage has more water and less proteoglycanproteoglycan

Collagen network also decreasedCollagen network also decreased Increased chondrocyte apoptosisIncreased chondrocyte apoptosis Deeper layers proliferate to compensate Deeper layers proliferate to compensate

and repair the damageand repair the damage

PathologyPathology The elastic and tensile strengthh The elastic and tensile strengthh

provided by proteoglycans and type 2 provided by proteoglycans and type 2 collagen producedcollagen produced

Imbalance in the matrix degradation and Imbalance in the matrix degradation and replacement by chondrocytesreplacement by chondrocytes

Causes Causes Mechanical stressMechanical stress Genetic factorsGenetic factors Increasing bone densityIncreasing bone density High estrogen levelHigh estrogen level

Clinical courseClinical course Insidious onsetInsidious onset Deep aching pain increasing with Deep aching pain increasing with

use, morning stiffness, crepitususe, morning stiffness, crepitus Osteophyte impingement in spinal Osteophyte impingement in spinal

foramina can cause neurologic foramina can cause neurologic symptoms like muscle spasms, symptoms like muscle spasms, muscle atrophy and neurologic muscle atrophy and neurologic deficitsdeficits

Hips, knees, lower lumbar and Hips, knees, lower lumbar and cervical vertebrae, proximal and cervical vertebrae, proximal and distal interphalangeal joints, 1distal interphalangeal joints, 1stst carpometacarpal and carpometacarpal and tarsometatarsaltarsometatarsal

Heberden nodes in fingers- Heberden nodes in fingers- prominent osteophytesprominent osteophytes

Slowly progressiveSlowly progressive Fusion dosent take place like Fusion dosent take place like

rheumetoid arthritisrheumetoid arthritis

GoutGout

Disorder caused by tissue Disorder caused by tissue accumilation of excessive accumilation of excessive amounts of uric acidamounts of uric acid

TypesTypes Primary- Primary-

Basic cause is unknownBasic cause is unknown Secondary-Secondary-

Those due to leukemia and CRDThose due to leukemia and CRD Inborn errors of metabolism(HGPRT)Inborn errors of metabolism(HGPRT)

MorphologyMorphology acute arthritisacute arthritis

Dense neutrophilic infiltrate Dense neutrophilic infiltrate permeating synovium and fluidpermeating synovium and fluid

Needle shaped monosodium urate Needle shaped monosodium urate crystals in the cytoplasm of crystals in the cytoplasm of neutrophils and synoviumneutrophils and synovium

Synovium is edematous and Synovium is edematous and congestedcongested

Scattered mononuclear infiltratesScattered mononuclear infiltrates

Chronic tophaceous arthritisChronic tophaceous arthritis Evolves from repetitive Evolves from repetitive

precipitation of urate crystals precipitation of urate crystals during acute attacksduring acute attacks

Urates heavily encrust the Urates heavily encrust the articular surface and form visible articular surface and form visible deposits in synoviumdeposits in synovium

Synovium- hyperplastic, fibrotic by Synovium- hyperplastic, fibrotic by the inflammatory cellsthe inflammatory cells

Pannus destroys underlying Pannus destroys underlying cartilagecartilage

Fibrous or bony ankylosisFibrous or bony ankylosis

Tophi in various sitesTophi in various sites Large aggregates of urate crystals Large aggregates of urate crystals

surrounded by intense surrounded by intense inflammatory reaction of inflammatory reaction of lymphocyes, macrophages and lymphocyes, macrophages and foreign body giant cells in attempt foreign body giant cells in attempt to engulf the masses of crystalsto engulf the masses of crystals

They appear in articular cartilage They appear in articular cartilage of jointsand periarticular of jointsand periarticular ligaments, tendons and soft ligaments, tendons and soft tissues including ear lobes, nasal tissues including ear lobes, nasal cartilages and skin of fingertipscartilages and skin of fingertips

Superficial tophi can lead to large Superficial tophi can lead to large ulcersulcers

Gouty nephropathyGouty nephropathy Multiple renal complications Multiple renal complications

associated with urate depositionassociated with urate deposition Medullary tophiMedullary tophi Intratubular precipitationsIntratubular precipitations Free uric acid crystalsFree uric acid crystals Renal calculiRenal calculi pyelonephritispyelonephritis

PathologyPathology PrimaryPrimary

OverproductionOverproduction Decreased renal excretionDecreased renal excretion Overproducion of uric acid due to Overproducion of uric acid due to

enzyme deficit in denovo or salvage enzyme deficit in denovo or salvage pathway- PRPP synthetase, amido pathway- PRPP synthetase, amido PRT, HGPRTPRT, HGPRT

HGPRT deficit- Lesch Nyhan HGPRT deficit- Lesch Nyhan syndromesyndrome

SecondarySecondary Increased urate production due to Increased urate production due to

chemotherapy for lymphoma or leukemiachemotherapy for lymphoma or leukemia Decreased excretion- CRD or azide diureticsDecreased excretion- CRD or azide diuretics

MechanismMechanismIncreased levels of uric acidIncreased levels of uric acid

Ppt of monosodium uratePpt of monosodium urate

ChemotaxisChemotaxisActivation of Activation of ComplementComplement

Local accumilation of neutrophils and Local accumilation of neutrophils and macrophages in jointmacrophages in joint

Chemokines, toxic free radicals and Chemokines, toxic free radicals and LTs(LT4). Neutrophils release lysosomal LTs(LT4). Neutrophils release lysosomal

enzymes and macrophages enzymes and macrophages ILs(IL1,IL6,TNF)ILs(IL1,IL6,TNF)

Activate synovial cells and cartilage cellsActivate synovial cells and cartilage cells

Release protease(collagenase)Release protease(collagenase)

Acute arthritisAcute arthritis

PseudogoutPseudogout

ChondrocalcinosisChondrocalcinosis AgeAge >50yrs. 50-60% in >80>50yrs. 50-60% in >80 No gender predespositionNo gender predesposition PathologyPathology Enzyme that produce or Enzyme that produce or

degrade pyrophosphatedegrade pyrophosphate

In hereditary varient, there is In hereditary varient, there is mutation of the transmembrane mutation of the transmembrane pyrophosphate transport channelpyrophosphate transport channel

Recruitment and activation of Recruitment and activation of inflammatory cells like in goutinflammatory cells like in gout

Mono or poly articularMono or poly articular Supportive therapy. But not to Supportive therapy. But not to

prevent or retard crystal formationprevent or retard crystal formation 50% has significant joint damage50% has significant joint damage

INFECTIOUS ARTHRITISINFECTIOUS ARTHRITISSuppurativeSuppurative

CauseCause Children under 2- H influenzaeChildren under 2- H influenzae Older children and adults- S Older children and adults- S

aureusaureus Late adolescence and young Late adolescence and young

adults- gonococcusadults- gonococcus SCC- SalmonellaSCC- Salmonella Deficiency in certain complement Deficiency in certain complement

(C5,C6,C7)- disseminated (C5,C6,C7)- disseminated gonococcal infectiongonococcal infection

Clinical featuresClinical features Sudden onset pain redness and Sudden onset pain redness and

swelling of jointswelling of joint Restricted motionRestricted motion Fever leukocytosis ESRFever leukocytosis ESR 90% nongonococcal inf in single 90% nongonococcal inf in single

joint, usually knee, hip, shoulder, joint, usually knee, hip, shoulder, elbow, wrist, sternoclavicular jointselbow, wrist, sternoclavicular joints

Aspiration is purulent and used for Aspiration is purulent and used for diagnosisdiagnosis

Lyme ArthritisLyme Arthritis

Borrelia burgdorferiBorrelia burgdorferi Four stages for diseaseFour stages for disease Stage 1Stage 1

Sprirochetes multiply at site of biteSprirochetes multiply at site of bite Expanding area of redness with Expanding area of redness with

indurated pale center- erythema indurated pale center- erythema chronicum migranschronicum migrans

Fever, LNEFever, LNE Disappears in few wks timeDisappears in few wks time

Stage 2 (Early disseminated stg)Stage 2 (Early disseminated stg) Spread hematogenously Spread hematogenously Secondary annular lesioinsSecondary annular lesioins LNE, migratory joint and muscle LNE, migratory joint and muscle

pain, cardiac arrythmias, pain, cardiac arrythmias, meningitis with CN involvementmeningitis with CN involvement

Abs develop in theis stage and Abs develop in theis stage and useful for serodiagnosisuseful for serodiagnosis

Some spirochetes escape host Some spirochetes escape host response by sequestering in CNS response by sequestering in CNS and IC forms in endothel cellsand IC forms in endothel cells

Stage 3 (late disseminated st)Stage 3 (late disseminated st) 2-3 yrs after initial bite2-3 yrs after initial bite Chronic arthritisChronic arthritis Severe damage to large jointsSevere damage to large joints EncephalitisEncephalitis Pathology Pathology

Due to immune response, borrelia Ags cross Due to immune response, borrelia Ags cross reacting with proteins in jointsreacting with proteins in joints

Remitting and migratoryRemitting and migratory Involve large joints- knees, shoulder, elbow, Involve large joints- knees, shoulder, elbow,

ankleankle

HistologyHistology Chronic papillary synovitis with Chronic papillary synovitis with

synoviocyte hyperplasiasynoviocyte hyperplasia Fibrin depositionFibrin deposition Mononuclear infiltrationMononuclear infiltration Onion skin thickening of arterial wallsOnion skin thickening of arterial walls

DiagnosisDiagnosis Serology and historySerology and history

TUMORSTUMORSGanglionGanglion

Small (<1.5 cm) cystSmall (<1.5 cm) cyst Often seen near joint capsule or tendon Often seen near joint capsule or tendon

sheath of wristsheath of wrist Firm nodulesFirm nodules Lack true cell lining as they arise by cystic Lack true cell lining as they arise by cystic

degeneration of connective tissuedegeneration of connective tissue Can be multilocular by coaleasion of of Can be multilocular by coaleasion of of

adjacent areas of myxoid changeadjacent areas of myxoid change Cyst fluid similar to synovial fluidCyst fluid similar to synovial fluid No communication with joint spaceNo communication with joint space Often asymptomaticOften asymptomatic Bible therapy as treatmentBible therapy as treatment

Synovial cystSynovial cyst

Herniation of synovium through a join Herniation of synovium through a join capsulecapsule

Massive enlargement of bursaMassive enlargement of bursa Eg:- Baker cyst seen in popletial fossaEg:- Baker cyst seen in popletial fossa

Villonodular TenosynovitisVillonodular Tenosynovitis

Several closely related neoplastic clonal Several closely related neoplastic clonal proliferationsproliferations

PVNTPVNT Joint synovium is affectedJoint synovium is affected MorphologyMorphology

Red brown to orange yellow Red brown to orange yellow Contorted mass of red brown folds, finger like Contorted mass of red brown folds, finger like

projections and nodulesprojections and nodules Cells resemble synovicytesCells resemble synovicytes It spread along surface andinfiltrate the It spread along surface andinfiltrate the

subsynovial compartmentsubsynovial compartment Hemosiderin depositsHemosiderin deposits Foamy macrophages, multinucleate giant cellsFoamy macrophages, multinucleate giant cells scarringscarring

Clinical featuresClinical features Monoarticular arthritis affecting Monoarticular arthritis affecting

knee(80%), hip, ankleknee(80%), hip, ankle Pain, locking and recurrent swellingPain, locking and recurrent swelling Aggressive lesion erode to adjacent Aggressive lesion erode to adjacent

bones and soft tissuebones and soft tissue

Giant Cell tumorGiant Cell tumor Tendon sheath commonly Tendon sheath commonly

involved (single tendon nodule)involved (single tendon nodule) Age 20-40Age 20-40

MorphologyMorphology Red brown to orange yellow Red brown to orange yellow Well circumscribed and containedWell circumscribed and contained Cells grow in solid nodular aggregateCells grow in solid nodular aggregate Cells resemble synovicytesCells resemble synovicytes Hemosiderin depositsHemosiderin deposits Foamy macrophages, multinucleate giant Foamy macrophages, multinucleate giant

cellscells ScarringScarring

Clinical featuresClinical features Solitary, slowl growing, painless massSolitary, slowl growing, painless mass

Affect wrist and finger tendon sheathsAffect wrist and finger tendon sheaths TreatmentTreatment

Surgical resection, recur locallySurgical resection, recur locally