OsteomyelitisMANAGEMENT

INFECTIOUS DISEASE PRESENTATIONS · 12 SECTIONS

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585 items

☷ Legend

01Approach to the Critical Patient/attcp73

Immediate priorities

›Time critical stabilization

›Airway compromise

›Altered mental status with loss of protective reflexes

›Severe sepsis with impending respiratory failure

›Shock physiology

›MAP target 65 mm Hg

›Lactate trending for perfusion

›Sepsis bundle triggers

›Suspected infection with hypotension after fluids

›Lactate 4 mmol/L or higher

›Limb threat triggers

›Acute compartment syndrome concern

›Critical limb ischemia concern

›Spine threat triggers

›New focal weakness

›Bowel or bladder dysfunction

›Early consultation and activation

›Orthopedics consultation triggers

›Suspected acute hematogenous osteomyelitis with abscess

›Failure of outpatient therapy

›Neurosurgery consultation triggers

›Suspected vertebral osteomyelitis with neurologic deficit

›Suspected spinal epidural abscess

›Infectious diseases consultation triggers

›Bacteremia

›Prosthetic material involvement

›Vascular surgery consultation triggers

›Diabetic foot infection with ischemia

›Suspected necrotizing infection

›Antibiotics timing decision

›Culture before antibiotics pathway

›Hemodynamic stability

›No neurologic compromise

›Planned image guided bone biopsy within 24 to 48 hours

›Immediate antibiotics pathway

›Sepsis or septic shock

›Rapidly progressive soft tissue infection

›Neurologic deficit

›Initial diagnostics bundle

›Blood cultures

›Two sets before antibiotics when feasible

›Repeat cultures for persistent bacteremia concern

›Baseline inflammatory markers

›CRP for trend

›ESR for supportive evidence

›Early imaging pathway selection

›Radiographs for baseline and alternate diagnoses

›MRI for extent and abscess

Key concepts

›Conceptual framework

›Infection pathways

›Hematogenous seeding

›Contiguous spread from soft tissue

›Direct inoculation from trauma or surgery

›High risk phenotypes

›Vertebral osteomyelitis

›Diabetic foot osteomyelitis

›Core management pillars

›Microbiologic diagnosis

›Source control

›Prolonged targeted antimicrobial therapy

PITFALLS

›Common errors

›Normal early radiograph interpreted as exclusion

›Radiographic changes often delayed 10 to 14 days

›MRI preferred for early disease

›Antibiotics started before cultures in stable patient

›Reduced culture yield from bone biopsy

›Prefer cultures first when safe

›Vertebral infection missed as mechanical back pain

›Fever often absent

›Elevated ESR or CRP supports infection

›Diabetic foot osteomyelitis missed

›Neuropathy masking pain

›Probe to bone positive increases likelihood

02History/hx48

Presentation patterns

›Symptom pattern and timeline

›Pain

›Localized deep pain

›Pain with weight bearing

›Systemic symptoms

›Fever

›Rigors

›Functional limitation

›Limp

›Reduced range of motion near involved bone

›Vertebral pattern

›Back pain

›Night pain

›Radicular symptoms

›Diabetic foot pattern

›Chronic ulcer duration

›Worsening drainage or odor

Risk factors and exposures

›Risk assessment

›Bacteremia sources

›Skin and soft tissue infection

›Endocarditis risk factors

›Immunocompromise

›Diabetes mellitus

›Chronic kidney disease

›Neutropenia

›Chronic corticosteroid therapy

›Vascular compromise

›Peripheral arterial disease

›Smoking

›Direct inoculation

›Open fracture

›Recent orthopedic surgery

›IVDU

›Pseudomonas risk

›MRSA risk

›Aquatic exposure

›Brackish water exposure

›Freshwater exposure

Microbiology clues

›Organism risk clues

›MRSA risk

›Prior MRSA colonization or infection

›Recent hospitalization

›Gram negative risk

›Recent urinary tract infection

›IVDU

›Anaerobe risk

›Chronic ischemic ulcer

›Foul smelling wound

03Physical Exam/exam45

General and systemic

›Systemic findings

›Vital signs

›Fever

›Tachycardia

›Sepsis features

›Hypotension

›Altered mental status

›Endocarditis stigmata

›New murmur

›Peripheral embolic signs

Local exam by site

›Local findings

›Bone and joint region

›Focal tenderness

›Pain with motion near adjacent joint

›Soft tissue

›Erythema

›Fluctuance suggesting abscess

›Wound evaluation

›Drainage

›Sinus tract

›Diabetic foot focused exam

›Ulcer assessment

›Ulcer depth

›Visible bone or tendon

›Probe to bone test

›Positive contact with hard gritty surface

›Higher likelihood of osteomyelitis when ulcer present

›Perfusion assessment

›Capillary refill

›Dorsalis pedis and posterior tibial pulses

›Spine and neurologic exam

›Spine tenderness

›Midline vertebral tenderness

›Pain with percussion

›Neurologic deficits

›Motor weakness

›Sensory level

›Saddle anesthesia

PITFALLS

›Misleading findings

›Afebrile presentation

›Common in vertebral osteomyelitis

›Common in older adults

›Minimal overlying skin changes

›Possible in hematogenous osteomyelitis

›Possible in early disease

04Differential Diagnosis/ddx29

Life threatening and limb threatening

›Critical differentials

›Septic arthritis ICD-10 M00

›Painful limited joint range of motion

›Effusion and warmth

›Necrotizing soft tissue infection ICD-10 M72.6

›Pain out of proportion

›Rapid progression

›Spinal epidural abscess ICD-10 G06.1

›Back pain

›Neurologic deficit

›Acute limb ischemia ICD-10 I74

›Pulselessness

›Cool mottled extremity

Mimics and related conditions

›Common mimics

›Cellulitis ICD-10 L03

›Superficial erythema

›No focal bony tenderness

›Gout ICD-10 M10

›Acute episodic course

›Hyperuricemia may be absent

›Charcot neuroarthropathy ICD-10 M14.6

›Warm swollen foot

›Minimal pain with neuropathy

›Fracture ICD-10 S82 and site specific

›Trauma history

›Point tenderness

›Malignancy ICD-10 C40 to C41

›Night pain

›Weight loss

05Laboratory Tests/lt36

Core labs

›Baseline inflammatory and organ function

›Complete blood count for leukocytosis and anemia

›Normal WBC does not exclude osteomyelitis

›Leukocytosis more common in acute disease

›CRP for diagnosis support and response tracking

›More responsive to treatment than ESR

›Decline supports clinical improvement

›ESR for diagnosis support

›Often elevated in vertebral osteomyelitis

›Slow to normalize

›Basic metabolic panel for renal dosing

›Creatinine trend for nephrotoxic antibiotics

›Potassium for TMP-SMX risk

›Liver enzymes for medication selection

›Rifampin hepatotoxicity risk

›Linezolid alternative considerations

Microbiology

›Cultures and pathogen identification

›Blood cultures for hematogenous source

›Highest yield in acute hematogenous osteomyelitis

›Persistent positivity suggests endovascular focus

›Bone biopsy culture for definitive microbiology

›Image guided biopsy for vertebral osteomyelitis

›Hold antibiotics if stable to improve yield

›Deep tissue culture from debridement

›Preferred over superficial swab

›Polymicrobial patterns common in diabetic foot

Additional tests by context

›Targeted labs

›Lactate for sepsis severity

›Elevated lactate supports hypoperfusion

›Trend for resuscitation response

›Hemoglobin A1c for diabetes control planning

›Poor control increases infection risk

›Impacts wound healing

›Creatine kinase for daptomycin safety baseline

›Myopathy monitoring

›Weekly monitoring during therapy

06Diagnostic Tests/dt56

Scoring Systems

›Risk and severity frameworks

›Sepsis screening tools

›qSOFA components

›RR 22 per minute or higher

›SBP 100 mm Hg or lower

›Altered mentation

›SOFA trend for organ dysfunction

›Rising score supports ICU consideration

›Lactate and vasopressor need integration

›Diabetic foot infection severity grading

›Mild infection

›Local infection limited to skin and subcutaneous tissue

›Erythema 2 cm or less around wound

›Moderate infection

›Deeper involvement

›Erythema greater than 2 cm

›Severe infection

›Systemic inflammatory response

›Hemodynamic instability

›Probe to bone test interpretation

›Positive test increases likelihood in diabetic foot ulcer

›Best performance in high pretest probability ulcers

›Negative test lowers likelihood in low risk ulcers

MRI

›MRI strategy

›Indications

›Suspected early osteomyelitis with nondiagnostic radiograph

›Suspected abscess or sinus tract

›Diagnostic performance

›High sensitivity for marrow edema

›Specificity reduced by recent surgery and Charcot changes

›Protocol considerations

›Contrast for abscess delineation when renal function allows

›Whole region imaging for skip lesions

›Interpretation pearls

›Marrow edema and enhancement pattern

›Cortical disruption and sinus tract support diagnosis

›CT role

›Indications

›Cortical bone detail for chronic osteomyelitis

›Surgical planning for sequestrum and involucrum

›Limitations

›Lower sensitivity for early marrow changes

›Metal artifact with hardware

›Technique pearls

›Contrast for soft tissue abscess when MRI unavailable

›Dual energy and metal artifact reduction when available

Ultrasound

›Ultrasound applications

›Soft tissue and fluid assessment

›Subperiosteal fluid collection in children

›Adjacent abscess localization for drainage

›Guidance

›Aspiration of superficial collections

›Vascular access for prolonged therapy

›Limitations

›Limited evaluation of marrow

›Cannot exclude osteomyelitis when negative

07Disposition/dispo28

Admission and level of care

›Disposition decision

›ICU indications

›Septic shock

›Rapidly progressive infection with organ dysfunction

›Inpatient admission indications

›Bacteremia

›Vertebral osteomyelitis

›Uncontrolled pain

›Need for IV antibiotics with monitoring

›Need for operative debridement

›Transfer indications

›Need for subspecialty surgery not available

›Spinal cord compression concern

›Outpatient management criteria

›Hemodynamic stability

›No neurologic deficits

›Reliable follow up within 48 to 72 hours

›Clear outpatient antibiotic plan and monitoring

Follow up and monitoring

›Post disposition plan

›Infectious diseases follow up

›Antibiotic selection and duration

›Lab monitoring schedule

›Orthopedics or podiatry follow up

›Wound care plan

›Offloading and immobilization plan

›Red flag return plan

›Worsening pain or swelling

›Fever recurrence

08Treatment/t146

Source control and supportive care

›Non antimicrobial management

›Source control

›Abscess drainage

›Percutaneous drainage when feasible

›Operative drainage for deep or loculated collections

›Debridement

›Removal of necrotic bone

›Removal of foreign material when possible

›Amputation considerations

›Non salvageable limb

›Extensive necrosis with ischemia

›Immobilization and offloading

›Splinting for pain control

›Reduced mechanical stress

›Improved comfort

›Diabetic foot offloading

›Total contact cast option

›Removable boot option

Empiric antibiotics

›Empiric therapy framework

›Timing

›If stable and biopsy planned then hold antibiotics

›If sepsis or neurologic deficit then initiate immediately

›Coverage targets

›Staphylococcus aureus including MRSA

›Streptococci

›Gram negative bacilli when risk factors present

›Adult empiric regimens

›Vancomycin IV

›Loading dose 20 to 25 mg per kg actual body weight for severe infection

›Maintenance 15 to 20 mg per kg IV every 8 to 12 hours

›AUC to MIC target 400 to 600

›If trough based monitoring then target trough 15 to 20 mg per L

›Cefepime IV for gram negative risk

›2 g IV every 8 to 12 hours

›Renal dose adjustment required

›Neurotoxicity risk with renal impairment

›Piperacillin tazobactam IV for polymicrobial diabetic foot

›4.5 g IV every 6 hours

›Renal dose adjustment required

›Enhanced nephrotoxicity risk with vancomycin

›Meropenem IV for ESBL risk

›1 g IV every 8 hours

›Seizure risk in renal impairment

›Reserve for high risk settings

Targeted antibiotics by organism

›Pathogen directed therapy

›MSSA

›Cefazolin IV

›2 g IV every 8 hours

›Renal dose adjustment required

›Preferred for many non CNS infections

›Nafcillin IV

›2 g IV every 4 hours

›Hepatotoxicity and neutropenia monitoring

›Sodium load consideration

›MRSA

›Vancomycin IV

›AUC to MIC target 400 to 600

›Nephrotoxicity monitoring

›Infusion reaction prevention with slower rate

›Daptomycin IV

›6 to 8 mg per kg IV once daily

›CK monitoring weekly

›Not for pneumonia

›Linezolid PO or IV

›600 mg every 12 hours

›Thrombocytopenia risk with prolonged use

›Serotonin syndrome risk with serotonergic drugs

›Streptococci

›Penicillin G IV

›4 million units IV every 4 hours

›Adjust for renal dysfunction

›Narrow spectrum option when susceptible

›Ceftriaxone IV

›2 g IV once daily

›Good bone penetration

›Biliary sludging risk

›Enterobacterales

›Ceftriaxone IV when susceptible

›2 g IV once daily

›Not for suspected AmpC high risk organisms

›Step down to oral based on susceptibility and stability

›Ciprofloxacin PO or IV when susceptible

›400 mg IV every 12 hours

›750 mg PO every 12 hours

›Tendinopathy and QT risk

›Pseudomonas aeruginosa

›Cefepime IV

›2 g IV every 8 hours

›Consider extended infusion strategy

›Renal dose adjustment required

›Piperacillin tazobactam IV

›4.5 g IV every 6 hours

›Consider extended infusion strategy

›Renal dose adjustment required

›Anaerobes

›Metronidazole PO or IV

›500 mg every 8 hours

›Neuropathy risk with prolonged use

›Alcohol interaction

›Clindamycin PO or IV when susceptible

›600 to 900 mg IV every 8 hours

›300 to 450 mg PO every 6 to 8 hours

›C difficile infection risk

Duration and route

›Treatment course planning

›Typical duration targets

›Acute hematogenous osteomyelitis adults

›6 weeks typical duration

›Longer duration for slow response or extensive disease

›Vertebral osteomyelitis

›6 weeks typical duration

›Extend for epidural abscess or persistent bacteremia

›Diabetic foot osteomyelitis

›6 weeks when bone retained

›Shorter course after complete resection with clean margins

›IV to oral transition criteria

›Hemodynamic stability

›Downtrending CRP

›Known susceptible organism

›High bioavailability oral option available

›Oral options with good bioavailability

›Linezolid

›600 mg every 12 hours

›CBC monitoring weekly

›Neuropathy risk with prolonged therapy

›Fluoroquinolone based regimen

›Ciprofloxacin 750 mg PO every 12 hours when susceptible

›Levofloxacin 750 mg PO once daily when susceptible

›QT and tendon risk counseling

›TMP-SMX

›1 to 2 double strength tablets PO every 12 hours

›Hyperkalemia monitoring

›Renal dosing adjustment

›Rifampin adjunct for staphylococcal hardware infection

›300 to 450 mg PO every 12 hours

›Use only with another active agent

›Drug interaction screening required

Evidence and guideline levels

›Evidence framing

›Class I recommendations

›Early source control for abscess

›Targeted therapy based on bone or deep tissue cultures when available

›Class IIa recommendations

›MRI for suspected vertebral osteomyelitis with elevated inflammatory markers

›IV to oral transition with high bioavailability agents in stable patients

›ACEP Level C considerations

›In stable patients culture acquisition before antibiotics when feasible

›Use of inflammatory markers to support diagnosis and track response

09Special Populations/sp44

Pregnancy

›Pregnancy considerations

›Imaging choices

›MRI without gadolinium preferred when feasible

›CT only when benefit outweighs fetal radiation risk

›Antibiotic safety

›Avoid tetracyclines

›Fetal bone and teeth effects

›Alternatives based on susceptibility

›Avoid fluoroquinolones when alternatives exist

›Cartilage toxicity concern

›Use only if benefits outweigh risks

›Beta lactams generally acceptable

›Cefazolin option for MSSA

›Ceftriaxone option for susceptible organisms

›Vancomycin acceptable when needed

›Therapeutic drug monitoring required

›Renal function monitoring

Geriatric

›Geriatric considerations

›Presentation differences

›Fever often absent

›Baseline back pain confounding vertebral osteomyelitis

›Medication safety

›Renal dosing for beta lactams and vancomycin

›QT risk with fluoroquinolones

›Complication risk

›Bacteremia and endovascular source higher likelihood

›Functional decline and fall risk from pain and immobility

Pediatrics

›Pediatric considerations

›Epidemiology and pathogens

›Staphylococcus aureus most common

›Kingella kingae in young children

›Diagnostic approach

›Ultrasound for subperiosteal abscess

›MRI for early diagnosis and extent

›Weight based dosing examples

›Cefazolin IV

›50 mg per kg per dose IV every 8 hours

›Maximum adult dose limits

›Clindamycin IV when MRSA risk and susceptible

›10 mg per kg per dose IV every 8 hours

›C difficile risk counseling for caregivers

›Vancomycin IV when MRSA concern

›15 mg per kg per dose IV every 6 hours

›Therapeutic drug monitoring required

10Background/b38

Epidemiology

›Epidemiology overview

›Common categories

›Hematogenous osteomyelitis

›Contiguous focus osteomyelitis

›Chronic osteomyelitis with sequestrum

›High risk groups

›Diabetes with foot ulcer

›IVDU with bacteremia risk

›Post operative and hardware associated infections

›Site patterns

›Vertebral osteomyelitis common in adults

›Metaphyseal long bone involvement common in children

Pathophysiology

›Pathophysiology essentials

›Inflammation and ischemia

›Increased intraosseous pressure

›Reduced perfusion and necrosis

›Chronic infection features

›Sequestrum formation

›Involucrum formation

›Biofilm pathobiology

›Hardware associated infections

›Reduced antibiotic penetration and tolerance

›Vertebral spread

›Disc space involvement in adults

›Epidural extension risk

Therapeutic Considerations

›Treatment principles

›Culture guided therapy priority

›Bone culture highest specificity

›Blood culture may guide when concordant

›Antibiotic penetration and duration

›Prolonged therapy required due to avascular necrotic bone

›High bioavailability oral therapy acceptable in selected patients

›Source control impact

›Debridement improves cure rates in chronic osteomyelitis

›Abscess drainage reduces bacterial burden

›Monitoring strategy

›CRP trend for response

›Imaging reserved for lack of clinical improvement

11Patient Discharge Instructions/pdi22

Copy discharge instructions

›Discharge instructions bundle

›Diagnosis explanation

›Bone infection concern requiring prolonged therapy

›Need for close follow up and lab monitoring

›Medications

›Antibiotics exactly as prescribed

›Do not stop early even if improved

›Wound care and activity

›Keep wound clean and dry if ulcer present

›Offloading device use as instructed

›Return immediately for

›Fever

›Worsening pain

›Increasing redness or swelling

›New drainage or foul odor

›New weakness or numbness

›Bowel or bladder changes

›Lightheadedness or fainting

›Follow up

›Infectious diseases appointment timing

›Surgical follow up timing

›Lab checks schedule for CBC and kidney function

12References/r20

Clinical guidelines and consensus

›Guideline sources

›Infectious Diseases Society of America guidance on native vertebral osteomyelitis

›Diagnostic pathway with blood cultures and MRI

›Culture directed therapy emphasis

›IDSA and IWGDF guidance on diabetic foot infection and osteomyelitis

›Severity grading for disposition

›Debridement and offloading principles

›Surviving Sepsis Campaign recommendations for sepsis and septic shock

›Early antibiotics for shock

›MAP target 65 mm Hg

Evidence based sources

›Evidence sources

›Bone biopsy culture as reference standard for pathogen identification

›Higher specificity than superficial swab

›Improved targeted therapy selection

›MRI as preferred imaging for early osteomyelitis and abscess extent

›High sensitivity for marrow edema

›Specificity limitations with postoperative change and Charcot

›High bioavailability oral therapy options for selected stable patients

›Criteria based transition strategies

›Monitoring for toxicity during prolonged courses

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Reviewed by SymptomDx Medical Team · Last reviewed June 16, 2026

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