Exam 1: Osteomyelitis

Infectious arthritis: Antimicrobial Treatment in Gonococcal infection

-Ceftriaxone 1 gm/day x 7-10 days -Oral amoxicillin or doxycycline (after C&S known)

Management of MRSA Osteomyelitis-CHILDREN --> Alternatives

-Daptomycin 6 mg/kg/dose IV daily -Linezolid 600 mg PO/IV BID for children ≥ 12 years old and 10 mg/kg/dose q8hr for children < 12 years old

Infectious arthritis: Antimicrobial Treatment in Children > 5 years and adults

-Penicillinase-resistant penicillin -Vancomycin if MRSA

Infectious arthritis Organisms by Age Group: Adolescents & adults (18-30 yrs)

-S. aureus -Neisseria gonorrhoeae

Infectious arthritis Organisms by Age Group: Children <5 years

-S. aureus -Streptococcus -Kingella kingae

Infectious arthritis Organisms by Age Group: Neonates

-S. aureus -Streptococcus -gram-negatives

Infectious arthritis Organisms by Age Group: Elderly

-S. aureus -gram-negatives -S. epidermidis

Role of Oral Antibiotics in Osteomyelitis:

-Usually indicated after 2 weeks of IV therapy in moderate infections -May be first line therapy in mild infections Empiric, outpatient therapy

Clinical Practice Guidelines for Management of MRSA Infectious Arthritis-CHILDREN

3-4 week course of therapy Same antibiotics as osteomyelitis

Empiric Treatment of Acute Osteomyelitis --> Risk of Salmonella

3rd generation cephalosporin

The specific duration of antibiotic therapy needed in the management of osteomyelitis is usually ____________

4 to 6 weeks

Optimal Duration of Treatment for MRSA Osteomyelitis in children

4-6 week course is recommended

Individuals at greatest risk for long-term sequelae are those who have symptoms present for more than ________ before starting therapy and those with infections occurring within the hip joint and infections caused by gram-negative organisms.

7 days

__________ osteomyelitis describes infections of recent onset, usually several days to 1 week

Acute

Children and elderly- Children: tibia, femur, humerus, fibula Adults > 50 years of age: vertebral

Acute Hematogenous Osteomyelitis

Local inflammation + systemic symptoms

Acute Hematogenous Osteomyelitis

Infectious arthritis Clinical Presentation

Acute systemic infection Fever, chills, malaise Painful, hot, swollen joint ↑ WBC ↑ ESR (erythrocyte sedimentation rate) Positive blood culture 50% of patients

Oral Alternatives: Extended spectrum penicillin or 3rd generation cephalosporin

Amoxicillin/clavulanate

Infectious arthritis: Diagnosis

Aspiration of joint fluid X-ray MRI

Disease-specific Organisms: Anaerobic bacteria

Bites, diabetic foot ulcer

_______________ is generally the more sensitive marker of response to therapy and often increases and decreases before the ESR

C-reactive protein

________ is generally the more sensitive marker of response to therapy and often increases and decreases before the ESR.

CRP

Empiric Treatment of Acute Osteomyelitis: IV first generation cephalosporin

Cefazolin

Empiric Treatment of Acute Osteomyelitis --> Risk of Pseudomonas

Ceftazidime or cefepime + aminoglycoside

Oral Alternatives: Cefazolin

Cephalexin

Clinical signs > 30 days Open bone injury Necrotic bone

Chronic Osteomyelitis

Risk Factors for infectious arthritis

Chronic illness Rheumatoid arthritis Joint trauma/surgery Joint prosthesis Decreased cellular immunity IV drug use Systemic corticosteroid use

It is recommended that when ______________ is used to treat osteomyelitis with mixed etiologies that include S. aureus, it should be combined with an antistaphylococcal drug such as dicloxacillin, cephalexin, or clindamycin.

Ciprofloxacin

______________ also has poor coverage against anaerobic organisms and staphylococci and emergence of resistant P. aeruginosa can be a problem

Ciprofloxacin

________________ is effective in the treatment of osteomyelitis caused by gram-negative bacteria, such as Enterobacter cloacae and Serratia marcescens; however, many strains of streptococci are relatively resistant

Ciprofloxacin

Empiric Treatment Algorithm for Osteomyelitis --> Local CA-MRSA resistance ≥ 10% AND local clindamycin resistance < 10%

Clindamycin (plus ceftriaxone if K. kingae suspected)

Management of MRSA Osteomyelitis-CHILDREN --> IF: stable with no bacteremia or intravascular infection AND IF: resistance rate is low (<10%)

Clindamycin 10-13 mg/kg/dose IV q6-8hr

Most prevalent Adults > 50 years of age Open fracture, surgery, prosthetics Afebrile, local pain and swelling Positive aspirate

Contiguous Osteomyelitis

_____________ can result from pressure ulcers or from adjacent soft tissue infections and most often involves the distal extremities.

Contiguous osteomyelitis

Monitoring Parameters:

Culture and sensitivity results Clinical signs of inflammation WBC ESR Compliance of outpatient therapy

Device-related Osteoarticular Infections (MRSA) --> Unstable implants, late-onset infections, or long duration of symptoms (>3 weeks)

Debridement + device removal

_____________ infections are typically polymicrobial involving aerobic and anaerobic organisms

Diabetic foot

Oral Alternatives: Nafcillin or oxacillin

Dicloxacillin

Cierny-Mader Staging System for Osteomyelitis - Stage 4:

Diffuse

Clinical Practice Guidelines for Management of MRSA Infectious Arthritis-ADULTS

Drainage or debridement should always be performed 3-4 week course of therapy Treat with same antibiotics as for osteomyelitis

Disease-specific Organisms: Staph epidermidis

Foreign body

Osteomyelitis Organism Isolation - Infants < 1 year

Group B streptococci, S. aureus, E. coli

Disease-specific Organisms: Bartonella henselae

HIV, kitten exposure

_________________ almost always involves one bone whereas contiguous *osteomyelitis* can present in multiple bones, especially when vascular insufficiency is an underlying risk factor.

Hematogenous osteomyelitis

____________________ is typically a disease of the growing bone in children and most cases occur in patients younger than 16 years of age

Hematogenous osteomyelitis

Cierny-Mader Staging System for Osteomyelitis - *A*

Host is healthy

Disease-specific Organisms: Pasturella multocida

Human or animal bite

_______________ require coverage for P. aeruginosa, and therefore, combination therapy with an aminoglycoside, fluoroquinolone, or anti-pseudomonal cephalosporin is needed.

IV drug abusers

Osteomyelitis in the ____________ patient has unique features. More than 50% of such infections involve the vertebral column and less than 20% of infections are located in either the sternoarticular or pelvic girdle.

IV drug user

Disease-specific Organisms: Fungi

Immunocompromised

Disease-specific Organisms: Enterobacteriaceae/PSA

Immunocompromised (P. aeruginosa-puncture wound to foot)

Pros/Cons of IV Antibiotics: *Cons*

Increased cost Patient inconvenience Risk of catheter-related complications: Infection Thrombophlebitis Malfunction

-50% gonococcal in US -gonococcal infxn are associated w/ polyarthritis

Infectious arthritis

Most common clinical presentation: Immobility of joint, no point of tenderness

Infectious arthritis

____________________ can result by spread from an adjacent bone infection, direct contamination of the joint space, or hematogenous dissemination (most common)

Infectious arthritis

Common site of infectious arthritis in adults:

Knee

Signs of infectious arthritis:

Knee joint pain, tenderness, swelling Markedly ↓ ROM

*Oral* Antibiotics for MRSA Infections in Children

Linezolid Clindamycin

Cierny-Mader Staging System for Osteomyelitis - *Bls*

Local and systemic host compromised

Cierny-Mader Staging System for Osteomyelitis - *Bl*

Local host compromised

Cierny-Mader Staging System for Osteomyelitis - Stage 3:

Localized

________ is much better treated with nafcillin than vanco

MSSA

Cierny-Mader Staging System for Osteomyelitis - Systemic Factors

Malnutrition Renal failure Hepatic failure Diabetes Immunosuppression

Cierny-Mader Staging System for Osteomyelitis - Stage 1:

Medullary

Optimal Duration of Treatment for MRSA Osteomyelitis in Adults

Minimum 8-week course of therapy Additional 1-3 months may be considered with oral rifampin-based combination therapy

Infectious arthritis: Antimicrobial Treatment in children <5 years

Nafcillin or cefazolin (if H. flu imm.) Ampicillin or cefuroxime (if no H. flu immunization)

Empiric Treatment of Acute Osteomyelitis: IV antistaphylococcal antibiotic

Nafcillin or oxacillin

Empiric Treatment Algorithm for Osteomyelitis --> Local CA-MRSA resistance < 10%

Nafcillin/oxacillin or cefazolin

___________ may have infectious arthritis because of a broad range of organisms, with S. aureus, group B Streptococcus, and gram-negative organisms being most common

Neonates

_____________________ is almost always monoarticular. The knee is the most commonly involved joint, but infections also can occur in the shoulder, wrist, hip, ankle, interphalangeal joints, and elbow joints.

Nongonococcal bacterial arthritis

Acute Hematogenous Osteomyelitis -- Usually only _________ infecting organism

ONE

Most common clinical presentation: Pain and tenderness of infected area

Osteomyelitis

Contiguous Osteomyelitis - Puncture wounds of the feet are commonly caused by _______________

P. aeruginosa

______________ is the most frequent organism in IV drug abusers

P. aeruginosa

_______________________ should be initiated and continued until there has been a resolution in the erythema, swelling, and tenderness and until the patient is afebrile.

Parenteral antibiotic therapy

Infectious arthritis: Antimicrobial Treatment in IV drug use

Penicillinase-resistant penicillin + aminoglycoside

Infectious arthritis: Antimicrobial Treatment in neonates

Penicillinase-resistant penicillin + aminoglycoside

Pros/Cons of IV Antibiotics: *Pro's*

Potential for better compliance Superior serum levels for some antibiotics Greater historical experience

____________________ is useful in identifying the focus of osteomyelitis

Radionuclide bone scanning

Device-related Osteoarticular Infections (MRSA) --> Oral therapy for 3 months (hips) or 6 months (knees)

Rifampin + FQ, TMP/SMX, tetracycline, or clindamycin

Contiguous-spread disease has several important differences compared with hematogenous osteomyelitis. _____________ is still the most common organism isolated, and infections with multiple organisms, including gram-negative bacilli, occur frequently.

S. aureus

Chronic Osteomyelitis - Pathogens

S. aureus, S. epidermidis P. aeruginosa, E. coli, S. marcescens

Osteomyelitis Organism Isolation - Children > 5 years

S. aureus, Streptococcus pyogenes

Osteomyelitis Organism Isolation - Children 1-5 years old

S. aureus, Streptococcus pyogenes, Streptococcus pneumoniae, Kingella kingae

Contiguous Osteomyelitis - Organisms

S. aureus, Streptococcus, S. epidermidis Gram negative rods Anaerobes

Patients with sickle cell anemia and related hemoglobinopathies are unique in that two thirds of bone infections in these patients are caused by __________ species, while the rest are usually caused by staphylococci and other gram-negative organisms.

Salmonella

Device-related Osteoarticular Infections (MRSA) --> Early onset (< 2 months post surgery) with a short duration of symptoms (≤ 3 weeks) AND debridement with device retention

Same antibiotics as osteomyelitis + rifampin 600 mg daily for 2 weeks

_____________ is most prevalent in children and the elderly.

Septic arthritis

Disease-specific Organisms: Salmonella

Sickle Cell disease

Osteomyelitis Organism Isolation - Adults

Staph epidermidis, S. aureus, P. aeruginosa, Serratia marcescens, E. coli

The bacteriology of hematogenous osteomyelitis is unique in that one pathogen, ______________________, is responsible for more than 80% of these infections,

Staphylococcus aureus

Acute Hematogenous Osteomyelitis: Organisms

Staphylococcus aureus Streptococci Gram negative rods

Infectious arthritis organism: Caused by Prosthetic joint infections

Staphylococcus epidermidis

Cierny-Mader Staging System for Osteomyelitis - Stage 2:

Superficial

Additional Therapies for Osteomyelitis:

Surgical debridement Antibiotic bead therapy Hyperbaric oxygen therapy

Cierny-Mader Staging System for Osteomyelitis - *Bs*

Systemic host compromised

*Oral* Antibiotics for MRSA Infections in Adults

TMP-SMX 4 mg/kg/dose (TMP component) BID + rifampin 600 mg Qday Linezolid 600 mg BID Clindamycin 600 mg q8hr Fluoroquinolone + rifampin Doxycycline/minocycline + rifampin

Despite the seriousness of osteomyelitis, often there are few laboratory abnormalities including;

The erythrocyte sedimentation rate (ESR), C-reactive protein, and WBC count

Empiric Treatment Algorithm for Osteomyelitis --> Local CA-MRSA resistance ≥ 10% AND local clindamycin resistance > 10%

Vancomycin (plus ceftriaxone if K. kingae suspected)

Empiric Treatment of Acute Osteomyelitis --> Allergy to penicillin or concern for CA-MRSA

Vancomycin or Clindamycin

Cierny-Mader Staging System for Osteomyelitis - Local Factors

Venous stasis Major vessel compromise Arteritis Scarring Neuropathy

Acute Hematogenous Osteomyelitis -___________: Staph, E. coli (sec. to urinary infxn), and Mycobacterium tuberculosis

Vertebral

In ___________________ the lumbar and thoracic regions are the locations of most infections and occurs most commonly in adults 50 to 60 years of age.

Vertebral osteomyelitis

___________________ produces nonspecific symptoms, such as constant back pain, fever or night sweats, and weight loss

Vertebral osteomyelitis

Infectious arthritis: use _________ if sensitive H. flu, *cefuroxime* if resistant H. flu

ampicillin

Predisposing factors in patients who have ____________ osteomyelitis include vascular disease, bites, contiguous infections, peripheral neuropathy, hematogenous spread, and trauma

anaerobic

Approximately one third of patients with ______________ have a poor joint outcome, such as severe functional deterioration.

bacterial arthritis

S. aureus, the single most common infecting organism, is found in 37% to 65% of cases of nongonococcal ________________

bacterial arthritis

Diagnosis: gold standard is __________ to determine etiology, but limited due to lack of uniform specimen collection and previous antibiotic use

biopsy

For patients with established vascular insufficiency, if anaerobes are suspected, an antianaerobic cephalosporin (e.g., _____________) or _____________ plus *ceftazidime* can be substituted.

cefoxitin, clindamycin

For patients with established vascular insufficiency need S. aureus, Streptococcus, anaerobes, and gram-negative coverage, Broad-spectrum therapy with a penicillinase-resistant penicillin in combination with _____________ is the preferred initial therapy.

ceftazidime

Bone infections in adults with a history of IV drug abuse require coverage for gram-negative organisms; therefore, empirical treatment with ___________ or ____________ 2 g IV every 8 hours.

ceftazidime or defepime

Osteomyelitis in patients with sickle cell hemoglobinopathies is commonly caused by either Salmonella or S. aureus. Thus, empirical antibiotics of first choice include _______________ or _______________

ceftriaxone or cefotaxime.

if the infection is located within the vertebrae, E. coli must be considered, and depending on the culture and susceptibility data, a switch to a ______________ may be needed.

cephalosporin

In children older than 5 years of age and in adults with *infectious arthritis*, initial therapy with a penicillinase-resistant penicillin or first-generation cephalosporin is appropriate to provide the necessary coverage against S. aureus. Therapy should be changed to ___________, ______________, or ______________ if the S. aureus is resistant to methicillin.

clindamycin, vancomycin, or linezolid

With _____________-spread osteomyelitis there is often an area of localized tenderness, warmth, edema, and erythema over the infected site.

contiguous

Patients with peripheral vascular disease are at risk for the development of ________________

contiguous osteomyelitis

The anaerobic infections in association with _____________ almost always occur within the feet. Bacteroides fragilis and Bacteroides melaninogenicus comprise the majority of anaerobic isolates

diabetes mellitus

In ___________________ that may have osteomyelitis, bone infections are most common in patients with foot ulcers greater than 3 mm and in patients with C-reactive protein levels greater than 3.2 mg/dL (32 mg/L).

diabetic patients

Children responding to initial parenteral therapy may be excellent candidates to receive follow-up oral therapy with an agents such as ________________________ depending on their culture and susceptibility results

dicloxacillin, cephalexin, clindamycin, or amoxicillin

Ampicillin may need to be added to the regimen to provide coverage against ______________

enterococci.

_______________ should not be used in children younger than 16 to 18 years of age or in pregnant women because of the potential to cause cartilage damage.

fluoroquinolones

In *infectious arthritis* disseminated _______________ infections often respond quickly to antibiotics. *Ceftriaxone* 1 g/day for 7 to 10 days is the treatment of choice for adults

gonococcal

Osteomyelitis resulting from puncture injuries to the feet are associated with ________________ infection or the bone and cartilage (sometimes classified as osteochondritis), especially infections caused by P. aeruginosa.

gram-negative

For children 5 years of age or younger, S. aureus and ______________ are the most common infecting organisms

group A streptococci

Infectious arthritis usually is acquired by _____________ spread

hematogenous

Infectious arthritis usually is acquired by _______________ spread

hematogenous

Approximately 50% of patients with ________________ will have positive blood cultures and may obviate the need for bone aspiration in these patients.

hematogenous osteomyelitis

The bacteriology of ________________________ is unique in that one pathogen, Staphylococcus aureus, is responsible for more than 80% of these infections, with group A Streptococci and Streptococcus pneumoniae accounting for a few cases. Kingella kingae, an organism that is part of the oral flora is emerging as a pathogen in children less than 3 years of age.

hematogenous osteomyelitis

Closed needle aspiration is indicated for all joints except the _____ (=open drainage)

hip

Closed-needle aspiration is recommended for all infected joints except the _____

hip

Common site of infectious arthritis in infants:

hip, hematogenous

In ___________________ some organisms, such as Neisseria gonorrhoeae, are especially likely to infect a joint during bacteremia.

infectious arthritis

Risk factors associated with adult _______________ are systemic corticosteroid use, preexisting arthritis, arthrocentesis, distant infection, diabetes mellitus, trauma, and other diseases

infectious arthritis

The three most important therapeutic maneuvers in the management of ___________________ are appropriate antibiotics, joint drainage, and joint rest.

infectious arthritis

Acute Hematogenous Osteomyelitis - Metaphysis of ____________

long bone

In infants younger than 1 month of age with *infetious arthritis*, the infecting organisms vary widely and empirical therapy thus must provide broad-spectrum coverage. A penicillinase-resistant penicillin such as _______________ plus a third-generation cephalosporin is appropriate.

nafcillin or oxacillin,

For children 5 years of age or younger, S. aureus and group A streptococci are the most common infecting organisms. Appropriate therapy in this age group is _______________ 150 to 200 mg/kg per day IV or ____________ 100 mg/kg per day

nafcillin or oxacillin, cefazolin

For children older than 5 years, S. aureus is the most likely infecting organism, and either _____________ 150 to 200 mg/kg per day IV or _______________ 100 mg/kg per day IV is recommended.

nafcillin or oxacillin, cefazolin

Hematogenous osteomyelitis in adults is caused frequently by S. aureus and thus is treated with 8 to 12 g/day of a penicillinase-resistant penicillin such as ____________ or a first-generation cephalosporin (e.g., __________). *Clindamycin* 2.4 g/day, or *vancomycin* 2 g/day (with normal renal function) can be used in adults allergic to penicillin

nafcillin, cefazolin

bone infections that occur after surgery or from contiguous spread, the required broad-spectrum coverage, ___________ 2 g IV every 4 hours plus ___________ or __________ 2 g IV every 8 hours should be used as initial therapy.

nafcillin, ceftazidime or cefepime

In children younger than 5 years of age with *infectious arthritis* who have been immunized for Hib should receive ___________, ______________, or _____________

nafcillin, oxacillin, or cefazolin

Because S. aureus, group B streptococci, and E. coli are the most common infecting organisms in _____________, an IV dosage of 150 mg/kg per day (given in four divided doses) of *oxacillin* or *nafcillin* plus *cefotaxime* 150 mg/kg per day (given in three to four divided doses) is appropriate

newborns

Patients with _____________________ almost always present with a fever, and 50% of patients have an elevated WBC count

nongonococcal bacterial arthritis

The average initial synovial WBC count is 10 × 103/mm3 (10 × 109/L) or greater in ___________________________

nongonococcal bacterial arthritis

The preferable time to obtain culture material in a patient with a chronic draining sinus is at the time of __________________

open surgical debridement.

Dicloxacillin, cloxacillin, and cephalexin (100 mg/kg per day) are effective _________ agents.

oral

Acute Hematogenous Osteomyelitis -- _____________ blood culture results

positive

Osteomyelitis resulting from ________________ to the feet are associated with gram-negative infection of the bone and cartilage (sometimes classified as osteochondritis), especially infections caused by P. aeruginosa. S. aureus is also a significant pathogen in these patients.

puncture injuries

The presence of _____________ usually indicates the presence of a septic joint.

purulent fluid

The most common form of osteomyelitis is from contiguous spread while that of _____________ is hematogenous spread.

septic arthritis

serum WBC, ESR, and C-reactive protein may not be useful acutely in ____________

septic arthritis

. Osteomyelitis in patients with _______________ may occur in any bone, but it most commonly involves the medullary cavity of long or tubular bones.

sickle cell disease

Children with culture-negative osteomyelitis can be managed as presumed _________________ disease with excellent long-term results.

staphylococcal

Cierny-Mader Staging System for Osteomyelitis - *C*

treatment worse than disease

If patients are allergic to penicillins or cephalosporins or are infected with MRSA, __________, ___________, or ____________ can be used

vancomycin, clindamycin, or linezolid

Osteomyelitis of the ____________ is also acquired hematogenously and occurs most frequently in patients older than 50 years of age

vertebrae