Infections of the Hip Infections of the Hip in childrenin children

Ram PulavartiRam Pulavarti

Septic arthritis of hipSeptic arthritis of hip

Thomas Smith 1874 - 21 cases of Thomas Smith 1874 - 21 cases of acute septic arthritis with mortality >50%acute septic arthritis with mortality >50%

Since the introduction antibiotics, Since the introduction antibiotics, mortality < 1%mortality < 1%

Early treatment Early treatment

Initial diagnosis must be on clinical basis Initial diagnosis must be on clinical basis

ImportanceImportance Common problem ‘Irritable hip’ Common problem ‘Irritable hip’

problems inherent to diagnosis and problems inherent to diagnosis and treatmenttreatment

Protean manifestations eg., pain, Protean manifestations eg., pain, limp, septicemia, mimic tumorlimp, septicemia, mimic tumor

Other conditions such as JRA Other conditions such as JRA

After diagnosisAfter diagnosis

What antibiotic before culture results are What antibiotic before culture results are known?known?

What if cultures are negative?What if cultures are negative? Route of administration? Route of administration? How long?How long? When is surgery indicated?When is surgery indicated? Diversity of organisms, various possible Diversity of organisms, various possible

locationslocations Numerous conditions associated with bone Numerous conditions associated with bone

and joint sepsis and joint sepsis

Hip DisasterHip Disaster

Risk of dislocationRisk of dislocation

AVNAVN

Shorter legShorter leg

Stiffness Stiffness

Infections of the hipInfections of the hip

Non specific: bacterialNon specific: bacterial Specific: TB, fungal, viralSpecific: TB, fungal, viral

HaematogenousHaematogenous Post TraumaticPost Traumatic IatrogenicIatrogenic

EpidemiologyEpidemiology Septic arthritis twice as common as osteomyelitis Septic arthritis twice as common as osteomyelitis

peak incidence in early years of the first decadepeak incidence in early years of the first decade

Osteomyelitis : peak incidence in the later years Osteomyelitis : peak incidence in the later years of the first decadeof the first decade

M > FM > F

A H O more in early autumn and late summer in A H O more in early autumn and late summer in both hemispheres (Gillespie, CORR 1973)both hemispheres (Gillespie, CORR 1973)

Higher incidence New Zealand Maoris, Australian Higher incidence New Zealand Maoris, Australian aborginalsaborginals

Osteomyelitis (AHO)Osteomyelitis (AHO)A changing diseaseA changing disease

A study from Glasgow: A study from Glasgow:

< 13 years of age AHO has dropped < 13 years of age AHO has dropped by more than 50% by more than 50%

incidence of subacute infections incidence of subacute infections increased from 12-42%increased from 12-42%

Craigan MA et al JBJS Br 1992; 74:541Craigan MA et al JBJS Br 1992; 74:541Jones NS et al JBJS Br 1987; 69:779Jones NS et al JBJS Br 1987; 69:779

Frequency of osteomyelitis and Frequency of osteomyelitis and septic arthritis according to septic arthritis according to age (yrs)age (yrs)

McCarthy JJ et al JBJS 2004McCarthy JJ et al JBJS 2004

SitesSites

Knee (41%)Knee (41%) Hip 23%Hip 23% Ankle 14%Ankle 14% Elbow 12%Elbow 12% Shoulder (4%)Shoulder (4%)

(Jackson and Nelson 1982)(Jackson and Nelson 1982)

Septic arthritisSeptic arthritis

Primary seeding of synoviumPrimary seeding of synovium

Secondary to metaphyseal infection eg., Secondary to metaphyseal infection eg., hip, shoulder, ankle, elbowhip, shoulder, ankle, elbow

Transepiphyseal vessels (up to 18 Transepiphyseal vessels (up to 18 months)months)

Directly from infection of epiphysisDirectly from infection of epiphysis

Septic arthritis of hip Septic arthritis of hip in infancyin infancy

Pathogenesis of Pathogenesis of Haematogenous infectionHaematogenous infection

Septic emboliSeptic emboli

Trauma, haematomaTrauma, haematoma

Reduced immunityReduced immunity

Glycocalyx (Biofilm)Glycocalyx (Biofilm)

Why metaphysis?Why metaphysis?

Vascular loop theoryVascular loop theory

Immature phagocytosis theoryImmature phagocytosis theory

Injury theoryInjury theory

Injection of bacteria as the hemorrhage Injection of bacteria as the hemorrhage is forming leads to infected haematomais forming leads to infected haematoma

(Morissy and Haynes 1989)(Morissy and Haynes 1989)

Course of metaphyseal Course of metaphyseal abscessabscess transphyseal vessels transphyseal vessels into the joint into the joint

Spreading infective thrombosis and Spreading infective thrombosis and periosteal stripping periosteal stripping dead bone dead bone

Epiphysis may separateEpiphysis may separate

the hard cortex the hard cortex sequestrum sequestrum

infection remains active as long as the infection remains active as long as the sequestrum is presentsequestrum is present

Course of metaphyseal Course of metaphyseal abscessabscess involucrum formationinvolucrum formation

Left alone, pus kills the periosteum Left alone, pus kills the periosteum

and no new bone is formedand no new bone is formed

Rupture of the periosteum: pus Rupture of the periosteum: pus tracks through a soft-tissue planes tracks through a soft-tissue planes ‘sinus’‘sinus’

Metaphyseal abscessMetaphyseal abscess

Septic arthritisSeptic arthritisPathologyPathology a fibrin-rich exudatea fibrin-rich exudate

Clotted exudate – a cast in the jointClotted exudate – a cast in the joint

Cartilage destruction: lysozymal enzymes dissolve the Cartilage destruction: lysozymal enzymes dissolve the glycosaminoglycans of the articular cartilage. glycosaminoglycans of the articular cartilage.

The femoral head + growth plate destructionThe femoral head + growth plate destruction

Organisms may vary in their ability to dissolve cartilage : Organisms may vary in their ability to dissolve cartilage : staphylococcus is most damagingstaphylococcus is most damaging

Hemophilus inflenzae and Gonococcus are the least Hemophilus inflenzae and Gonococcus are the least damagingdamaging

DiagnosisDiagnosis

Clinical suspicionClinical suspicion Examination :Examination : lap examlap exam temp is often normaltemp is often normal examine everything before trying examine everything before trying

the joint – because as soon as this the joint – because as soon as this touched, all cooperation is gonetouched, all cooperation is gone

Look: is it swollen, warm, can the Look: is it swollen, warm, can the child move it child move it

TemperatureTemperature Klein et al: Klein et al:

Temp below 38Temp below 3800C in 31%C in 31%

Del Bacarro et al: Del Bacarro et al:

Mean temp 38.1Mean temp 38.100C degrees C C degrees C

Gandini Gandini

Mean temp: 39.2Mean temp: 39.200C C

Kocher criteriaKocher criteria(for child with painful hip)(for child with painful hip)

non-weight-bearing on affect side, non-weight-bearing on affect side, Sedimentation rate greater than 40 mm/hr,Sedimentation rate greater than 40 mm/hr, fever, and fever, and WBC count of >12,000 mm3;WBC count of >12,000 mm3;

when 4/4 criteria are met, 99% chance that the child when 4/4 criteria are met, 99% chance that the child

has septic arthritis;has septic arthritis;when 3/4 criteria are met, 93% chance of septic arthritis;when 3/4 criteria are met, 93% chance of septic arthritis;when 2/4 criteria are met, 40% chance of septic arthritis; when 2/4 criteria are met, 40% chance of septic arthritis;

when 1/4 criteria are met, 3% chance of septic arthritis;when 1/4 criteria are met, 3% chance of septic arthritis;                   

Ref:Ref:Kocher et al JBJS 2004, Kocher et al JBJS 2004,

OrganismsOrganisms Newborn Newborn Staphylococcus 36%Staphylococcus 36% Streptococcus (21%)Streptococcus (21%) E.coli 14%E.coli 14%

1month to 5 yrs: 1month to 5 yrs: hemophilus inflenzae (31%)hemophilus inflenzae (31%)

Children over 5 years: staphylococcusChildren over 5 years: staphylococcus Sexually active teenager - GonococcusSexually active teenager - Gonococcus

Negative culturesNegative cultures

Because many patients with Because many patients with

septic arthritis have negative septic arthritis have negative cultures, cultures,

it is important to use criteria it is important to use criteria

that include those patientsthat include those patients

DiagnosisDiagnosis CBCCBC ESR: most sensitive test; 90% elevated to medium levelsESR: most sensitive test; 90% elevated to medium levels CRPCRP

Blood culturesBlood cultures

Sickle-cell test for black childrenSickle-cell test for black children

X ray: to rule out preexisting lesions; X ray: to rule out preexisting lesions;

Bone Scan: useless at distinguishing septic from nonseptic Bone Scan: useless at distinguishing septic from nonseptic jointsjoints

UltrasoundUltrasound

Definitive test: needle aspiration of a septic jointDefinitive test: needle aspiration of a septic joint

LaboratoryLaboratory

Leukocyte count – not reliable in Leukocyte count – not reliable in early stagesearly stages

Only 25% of infants and children Only 25% of infants and children with osteomyelitis have a leukocyte with osteomyelitis have a leukocyte count above normal for their agecount above normal for their age

Only 65% of infants and children Only 65% of infants and children with osteomyelitis had the with osteomyelitis had the differential count abnormaldifferential count abnormal

LaboratoryLaboratory

Most useful lab test in bone and Most useful lab test in bone and joint sepsis: joint sepsis:

CRP CRP

ESRESR

Laboratory dataLaboratory data Normal ESR, CRP or WCC does not exclude the Normal ESR, CRP or WCC does not exclude the

presence of infectionpresence of infection

Average ESR between 37-94mm/hrAverage ESR between 37-94mm/hr

Del Becarro et al. Del Becarro et al. ESR 44 in septic arth :: 19 trans synovitisESR 44 in septic arth :: 19 trans synovitis

Klein et al average ESR 51mm/h, 95% had an ESR Klein et al average ESR 51mm/h, 95% had an ESR >20mm>20mm

Gandini 2003: Gandini 2003: ESR 65mm/hr; all children >20mm/hrESR 65mm/hr; all children >20mm/hr CRP mean CRP 144mg/L, all > 20mg/LCRP mean CRP 144mg/L, all > 20mg/L

ESRESR

non specificnon specific unreliable in a neonate, anaemia, sickle cell unreliable in a neonate, anaemia, sickle cell

disease, on steroidsdisease, on steroids almost always elevated 48-72hrs of onset of almost always elevated 48-72hrs of onset of

infection infection returns to normal over 2-4 weeks after returns to normal over 2-4 weeks after

elimination of the infectionelimination of the infection less reliable in the first 48hrs than after less reliable in the first 48hrs than after

48hrs48hrs continues to rise for 3-5 days after institution continues to rise for 3-5 days after institution

of successful therapy of successful therapy therefore not a good means of response to therefore not a good means of response to

treatment in the first weektreatment in the first week

CRPCRP

inflammation or traumainflammation or trauma May rise within 6hrs then increases May rise within 6hrs then increases

several hundred fold several hundred fold peak within 36-50hrspeak within 36-50hrs Falls quickly to normal with Falls quickly to normal with

successful treatment successful treatment early diagnosis and resolution of early diagnosis and resolution of

inflammation inflammation

AspirateAspirate

rinse with heparin before aspiraterinse with heparin before aspirate

Gram stain : organisms in about Gram stain : organisms in about one thirdone third of bone and joint of bone and joint aspiratesaspirates

CulturesCultures

Blood culture: 30-50% yield Blood culture: 30-50% yield

The yield from cultures decreases The yield from cultures decreases with previous antibiotic therapy with previous antibiotic therapy

MicrobiologyMicrobiology Gandini: Gandini:

27% joint fluid positive culture27% joint fluid positive culture

72% blood cultures72% blood cultures

no Haemophilus influenza cases no Haemophilus influenza cases

Bennet and Namnyak Bennet and Namnyak

joint fluid positive culture in 91%joint fluid positive culture in 91%

Blood culture: 42.5%Blood culture: 42.5%

No string in turbid fluid of septic No string in turbid fluid of septic jointsjoints

hyaluronate is broken down by hyaluronate is broken down by enzymesenzymes

Differential diagnosisDifferential diagnosis

The Hip – leukemia, pelvic The Hip – leukemia, pelvic osteomyelitis, transient synovitis, osteomyelitis, transient synovitis, discitis, appendicitisdiscitis, appendicitis

Rheumatoid arthritis hardly ever, Rheumatoid arthritis hardly ever, begins in the hipbegins in the hip

Organisms causing Organisms causing AHOAHOAge groupAge group OrganismOrganism AntibioticAntibiotic

NeonatesNeonates Group B Group B streptococcus, Sta. streptococcus, Sta.

aureus, gram-aureus, gram-negative rodsnegative rods

Cefotaxime or Cefotaxime or Oxacillin and Oxacillin and gentamicingentamicin

Infants and childrenInfants and children Sta. aureus (90%)Sta. aureus (90%) OxacillinOxacillin

Pts with sickle cell Pts with sickle cell disease disease

Staphylococcus Staphylococcus aureus or aureus or

Sa,monellaSa,monella

Oxacillin and Oxacillin and ampicillin or ampicillin or

cefotaxime or cefotaxime or chroamphenicol chroamphenicol

Negative culturesNegative culturesFive of the six criteria to diagnose septic Five of the six criteria to diagnose septic arthritis: (Morey et al.)arthritis: (Morey et al.)

Temp > 38.3Temp > 38.30 0 cc Pain in suspected joint made worse by Pain in suspected joint made worse by

motionmotion Swelling of suspected jointSwelling of suspected joint Systemic symptomsSystemic symptoms Absence of other pathologic processesAbsence of other pathologic processes A satisfactory response to antibioticA satisfactory response to antibiotic

TreatmentTreatment

DrainageDrainage Move the joint: to prevent Move the joint: to prevent

intraarticular adhesionsintraarticular adhesions Dislocated hip should be abducted Dislocated hip should be abducted

to reduce itto reduce it Monitor serum bactericidal titers – Monitor serum bactericidal titers –

changes to oral antibiotics at 1 wkchanges to oral antibiotics at 1 wk Abs for 3-6 wks when ESR returns Abs for 3-6 wks when ESR returns

to normalto normal

Never let the sun set Never let the sun set

on pus under pressureon pus under pressure

Any child with spontaneous acute Any child with spontaneous acute metaphyseal pain and tenderness metaphyseal pain and tenderness

has osteomyelitis until proven has osteomyelitis until proven otherwiseotherwise

TreatmentTreatment

Parenteral antibiotics Parenteral antibiotics

Duration of antibiotic – 2weeks to Duration of antibiotic – 2weeks to 4 months4 months

Sequelae of SepticSequelae of SepticArthritis of the HipArthritis of the Hip Partial or complete destruction of the proximal femoral physisPartial or complete destruction of the proximal femoral physis

Osteonecrosis of the femoral headOsteonecrosis of the femoral head

Trochanteric overgrowthTrochanteric overgrowth

Pseudarthrosis of the femoral neckPseudarthrosis of the femoral neck

Complete dissolution of the femoral neck and headComplete dissolution of the femoral neck and head

Progressive limb-length discrepancyProgressive limb-length discrepancy

Varus or valgus alignment of the femoral headVarus or valgus alignment of the femoral head

Hip dislocationHip dislocation

Ankylosis of the hip jointAnkylosis of the hip joint

This is not so hard!This is not so hard!

Bottom lineBottom line

Early, accurate diagnosis of septic Early, accurate diagnosis of septic arthritis of the hip in children is arthritis of the hip in children is criticalcritical

Poor outcomes with a delay in Poor outcomes with a delay in diagnosisdiagnosis

High degree of suspicion and High degree of suspicion and Clinical judgementClinical judgement