osteomyelitis

Osteomyelitis is an inflammation of bone caused by an infecting organism

it may remain localized, or spread through the bone to involve the marrow, cortex, periosteum, and soft tissue

CLASSIFICATion acute, subacute, chronic; exogenous hematogenous.

ACUTE HEMATOGENOUS OSTEOMYELITIS

it is caused by bacteremia localized trauma debilitation from a chronic illness, malnutrition, inadequacy of the immune system,.

younger than 2 years between 8 and 12 years age

In children yanger than 2years vessels cross the physis and may allow the spread of infection into the epiphysis Otherwise, the physis acts as a barrier

T he metaphysis has relatively fewer phagocytic cells, allowing infection to occur more easily in this area.

abscess breaks through the thin metaphyseal cortex and forms a subperiosteal abscess.

acute osteomyelitis in an infant may cause shortening or angular deformity as a result of damage to the physis or epiphysis.

In children older than 2 years of age, the physis still prevents the spread of a metaphyseal abscess into the epiphysis.

in children older than 2years of age, the metaphyseal cortex is thickerthe spread of infection into the diaphysis, the endosteal blood supply to the bone will be jeopardized. The periosteum also is lifted off the bone by the abscess, endangering the periosteal blood supply Results inextensive sequestrum chronic osteomielitis

Hematogenous osteomyelitis in this age usually affects the vertebral bodies. epiphysis, metaphysis, or diaphysis; abscesses spread slowly, and large sequestra rarely form.

After the physes have closed, exogenous osteomyelitis becomes more common

Some physis is within capsule, metaphyal osteomyelitis may cause septic arthritis proximal femur proximal humerus, radial neck distal fibula

Older children Staphylococcus aureus adults Gram-negative exogenous. Mixed floral (gram positive and gramnegative negative heroin add Pseudomonas chronically ill patients fungal sikel cell hemoglobinopathies Salmonella infants, S. aure, B Streptococcus and gram-negative colifor also arecommon.

DIAGNOSIS history pain weekness high or low tempratur anorexi

Paraclenic CBC ESR X RAY MRI blood cultur bone scan bone aspiration

Magnetic resonance imaging shows changes in the marrow and soft tissues from an inflammatory response.

Blood cultures yield the infecting organism in about 50% of patients.

Bone aspiration should be performed to aid in establishing an accurate bacteriological diagnosis and to determine if an abscess is present.

TREATMENT

Surgery and antibiotic

areas of simple inflammation without abscess formation will respond to antibiotics alone

1 ) an appropriate antibiotic will be effective before pus formation; (2) antibiotics will not sterilize avascular tissues and purulent material that must be removed surgically; (3) if such removal is effective, then antibiotics should prevent their reformation and therefore primary wound closur should be safe; (4) surgery should not further damage already ischemic bone and soft tissue (5) antibiotics should be continued after surgery.

Acute septic arthritis results from bacterial invasion of a joint space

hematogenous spread, direct inoculation from trauma or surgery, contiguous spread from an adjacent site of osteomyelitis or cellulitis.

Age, young children elderly individuals

Predisposing factor immature immune system, immune compromise for any reason neoplasms, alcoholism, diabetes mellitus, rheumatoid arthritis, systemic lupuserythematos malnutrition, chronic hepatic or renal failure, intravenous drug use, previous joint trauma or arthritis

serious complications in children destruction of the epiphysis avascular necrosis from increased intracapsular pressure and septic effusion.

neonates, Streptococcus neonates who are hospitalized, Staphylococcus, Candida, and gram-negative children under 2 years of age Haemophilus influenzae type B systemic lupus erythematosus, Salmonella intravenous drug user gram-negative pseudom onas. neonates, Streptococcus neonates who are hospitalized, Staphylococcus, Candida, and gram-negative children under 2 years of age Haemophilus influenzae type B systemic lupus erythematosus, Salmonella intravenous drug user gram-negative pseudom onas.

Diagnose, inflammatory responses are blunted signs fever, swelling, erythema, and pain may be minimal or lacking. The only finding in a neonate may be infection at another site (e.g., the umbilical catheter), irritability, failure to thrive, asymmetry of limb position, or displeasure at being handled.

. Erythrocyte sedimentation rates C-reactive protein synovial leukocyte counts above 50,000/mm3 28,000/mm3 polymorphonuclear cells, if more than90 joint aspiration

preparations of Haemophilus endotoxin and a staphylococcal culture medium stimulate release of metalloproteases, including collagenase. The release of these enzymes appears to be mediated by the cytokine interleukin-1 (IL-1), which probably is produced locally by monocytes but may be secreted by chondrocytes.

Treatment of acute septic arthritis: (1) the joint must be adequately drained, (2) antibiotics (3) the joint must be rested in a stable positione

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