Term
| pathophysiology of pyogenic osteomyelitis |
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Definition
| primary site of infection is usually in the metaphysial region, the infection may spread to involve the cortex and form a subperiosteal abscess; may spread into the medullary cavity, rarely may spread into the joint space. transient bacteremia breaks through cortex to form subperiosteal abscess-> local acute inflammation (osteomyelitis) |
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Term
| Metaphyseal Location for osteomyelitis |
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Definition
• Dilated vessels and sluggish flow
• Rapid growth
• Thrombosed by trauma |
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Term
| Direct Inoculation for osteomyelitis |
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Definition
• Penetratinginjuries
• Surgery
– Fracture fixation |
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Term
| Predispositions to Osteomyelitis |
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Definition
• Trauma
• Poor nutrition
• Prior Infection
• Immunocompromised
• Sickle cell disease |
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Term
| Diagnosis of Osteomyelitis- history, PE, lab tests, diagnostic imaging |
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Definition
• History
– Antecedent infection
– Trauma
– Pain and fever
– Nausea, vomiting, seizure
• Physicalexam – Pain
– Swelling, redness, heat
• Laboratorytests – CBC, ESR, CRP – Culture
• DiagnosticImaging – Plain x-ray
– Bone scans – MRI |
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Term
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Definition
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Term
| Treatment of Osteomyelitis |
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Definition
• Medical
– Antimicrobials
– Treat 4-6 weeks
• Surgical – Debride
– Decompress – Revascularize |
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Term
| antibiotics color-coded coverage |
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Definition
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Term
[image]
acute osteomyelitis treatment |
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Definition
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Term
| chronic osteomyelitis treatment agents |
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Definition
| ciprofloxacin, ofloxacin, ofloxacin + rifampin, levofloxacin + rifampin, linezolid, SMX-TMP, SMX-TMP/linezolid + rifampin |
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Term
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Definition
| SEPTIC UNTIL PROVEN OTHERWISE |
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Term
| Risk Factors for Septic Arthritis |
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Definition
• Previous arthritis
• Trauma
• Diabetes Mellitus
• Immunosuppression
• Bacteremia
• Sickle cell anemia
• Prosthetic joint |
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Term
| Pathogenesis of Septic Arthritis |
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Definition
• Bacteria enter joint and deposit in synovial lining.
– Hematogenous spread or local invasion
– Acute inflammatory response
• Rapid entry into synovial fluid
– No basement membrane |
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Term
| Clinical Presentation of Septic Arthritis |
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Definition
• Acute monoarthritis
– Cardinal signs of inflammation • Erythema, heat, swelling, pain
• +/- Fever
• +/- Leukocytosis
• Atypical presentations are not uncommon |
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Term
| most common joint for septic arthritis |
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Definition
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Term
| Polyarticular Septic Arthritis |
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Definition
• More likely to be over 60 years
• Average of 4 joints
– Knee, elbow, shoulder and hip predominate
• High prevalence of RA
• Often without fever and leukocytosis
• Blood cultures+75%
• Synovial fluid culture+90%
• Staph and Strep most common
• POOR PROGNOSIS
– 32%mortality (compared to 4% with monoarticular disease) |
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Term
| Synovial Fluid Analysis in Septic Arthritis |
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Definition
• Cell count: >50,000 wbcs/mm3
• Differential: >75% PMNs
• Glucose: Low
• Gram stain : relatively insensitive test
• Culture: postive
Always use a wide bore needle when you suspect infection, as pus may be very viscous and difficult to aspirate |
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Term
| staph aureus infectious arthritis |
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Definition
| healthy adults, skin breakdown, previously damaged join (rheumatoid arthritis), prosthetic joint |
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Term
| strep infectious arthritis |
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Definition
| healthy adults, plenic dysfunction |
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Term
| neisseria gonorrhea infectious arthritis |
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Definition
| healthy adults (particularly young, sexually active), associated tenosynovitis, vesicular pustules, late complement deficiency, negative synovial fluid culture and gram stain |
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Term
| aerobic gram negative bacteria infectious arthritis |
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Definition
| immune compromised hosts, GI infection |
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Term
| anaerobic gram neg bacteria infectious arthritsi |
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Definition
| immune compromised hosts, GI infection |
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Term
| mycobacterial sp infectious arthritis |
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Definition
| immune compromised host, recent travel to or residence in an endemic area |
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Term
| fungal species (sporotrichosis, cryptococcus, blastomycosis infectious arthritis |
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Definition
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Term
| spirochete (borellia burgdorferi) infectious arthritis |
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Definition
| exposure to ticks, antecedent rash, knee joint involvement |
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Term
| mycoplasma hominis infectious arthritis |
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Definition
| immune compromised hosts w prior GI manipulation |
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Term
| When to order special cultures for septic arthritis |
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Definition
• History of TB exposure
• Trauma
• Animal bite
• Live in or travel to endemic sites for Fungi or Borrelia
• Immunocompromised host
• Unresponsive to conventional therapy |
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Term
| Septic Arthritis Radiographs |
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Definition
– Minimal diagnostic utility
– Document any existing joint damage
– Evaluate for possible osteomyelitis |
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Term
| Septic Arthritis Management |
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Definition
• Jointaspiration
– Daily or more frequently as needed.
• Antibiotictherapy
– Based on gram stain/culture and clinical factors
– Duration is variable and depends on organism and host factors
• Surgicalintervention
– Only necessary if patient is not responding after 48 hours of appropriate therapy |
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Term
| Empiric Therapy for Septic Arthritis |
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Definition
• Must cover Staph and Strep – Oxacillin
– Vancomycin if PCN-allergic or if concern for MRSA
• If infection is hospital acquired or prosthetic joint- cover gram negatives
– 3rd generation cephalosporin
• Empiric coverage for GC is recommended because of the high prevalence rate |
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Term
| Special Populations Septic Arthritis |
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Definition
• Prosthetic joints
• Patients on TNF inhibitors • Sickle cell anemia
• HIV disease
• Transplant setting |
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Term
| IV Drug Users Septic Arthritis |
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Definition
• Multiple risk factors for septic arthritis – Soft tissue infections
– Transient bacteremia
– Other comorbidities- hepatitis, endocarditis, HIV
• Unusual sites
– Fibrocartilagenous joints- SC, costochondral, symphysis
• Unusual organisms
– S. aureus still most common
– Gram negative infections next most common • Pseudomonas,Serratia,Enterobactersp.
– Candida |
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Term
| Prosthetic Joint Infections stages, septic arthritis |
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Definition
• Stage I
– Within 3 months of surgery
– Usually transmitted at the time of surgery
– Staph and other gram positives most common – Pain, wound drainage, erythema, induration
• Stage II
– 3-24 months
• Stage III
– >2 years post-surgery
– Usually caused by hematogenous spread to abnormal joint surfaces
– Joint pain predominates |
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Term
| Prosthetic joint infections septic arthritis |
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Definition
• Synovial fluid analysis
• May require biopsy
• If cultures are positive
– Remove prosthesis
– Treat with parenteral antibiotic until sterile • Usually 6 weeks +
– Reoperate • Revision is at high risk for recurrent infection |
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Term
| Disseminated Gonococcal Infection septic arthritis info |
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Definition
• Occurs in 1-3% on patients infected with GC
• Most patients have arthritis or arthralgia as a principal manifestation
• Common cause of acute non-traumatic mono- or oligo-arthritis in the healthy host |
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Term
| Disseminated Gonococcal Infection septic arthritis host factors |
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Definition
• Women > men
• Recent menstruation
• Pregnancy or immediate postpartum state
• Complement deficiency (C5-C9)
• SLE |
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Term
| Gonococcal Arthritis- Presentation |
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Definition
• Tenosynovitis, rash, polyarthralgia – Wrist, finger, ankle, toe
– Painless pustules or vesicles
– Fever and malaise
– Synovial cultures usually negative
• Urethral and cervical cultures may be helpful
• Purulent arthritis
– Knee, wrist, or ankle most common – Synovial cultures usually positive
• These two presentations may overlap |
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Term
| Gonococcal Arthritis- Treatment |
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Definition
• Ceftriaxone 1gm IV or IM q24 hours
• Spectinomycin 2 gm IV or IM q12 hours for cephalosporin allergic patients
• May use fluoroquinolones if susceptible |
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