Updated: 2/14/2019

Septic Arthritis

Topic
Review Topic
0
0
Questions
1
0
0
Snapshot
  • A 22-year-old man presents to his primary physician's office for worsening knee pain. He reports that his symptoms began approximately 1 week ago and has worsened to the point of not being able to bend the knee. He states to being sexually active with multiple partners and inconsistently using condoms. On physical exam, the left knee is erythematous, swollen, and tender to palpation. There is decreased range of motion on the affected joint. Laboratory testing demonstrates an elevated erythrocyte sedimentation rate and C-reactive protein. An athrocentesis is obtained and demonstrates a white blood cell count of 55,000 cells/μL and gram-negative organisms. Empiric antibiotics are administered and orthopedic surgery is consulted.
Introduction
  • Clinical definition
    • infection of a joint leading to arthritis that can be caused by
      • bacteria
      • fungi
      • mycobacteria
  • Epidemiology
    • risk factors
      • increasing age
      • diabetes mellitus
      • rheumatoid arthritis
      • prosthetic joints
      • intravenous drug abuse
      • skin infection
      • alcohol use
      • sexual activity
  • Etiology 
    • Staphylococcus aureus
      • most common cause
    • streptococci
      • second most common cause of nongonococcal arthritis
    • Neisseria gonorrhoeae
      • suspect in healthy and sexually active patient
    • Pseudomonas aeruginosa
      • typically seen in healthcare-associated infections
    • Borrelia burgdorferi
      • typically seen in patients in endemic areas
    • Mycobacterium tuberculosis
  • Pathogenesis
    • infectious agent can be spread to the joint via
      • the blood (hematogenously)
      • direct inoculation
      • contiguously from the adjacent skin (e.g., cellulitis and cutaneous ulcers)
    • once the infectious agent arrives to the synovial membrane an inflammatory response ensues
  • Prognosis
    • dependent on a number of comorbid conditions (e.g., age and immunosuppresion)
      • ranges 10-15%
Presentation
  • Symptoms
    • fevers may be present
    • joint pain
  • Physical exam
    • in most cases 1 joint is affected
      • a joint that is
        • warm
        • erythematous
        • swollen
        • restricted to movement
Imaging
  • Radiography
    • indication
      • can be used to get a baseline assessment of joint damage
Studies
  • Labs
    • ↑ erythrocyte sedimentation rate and C-reactive protein
  • Arthrocentesis
    • the best initial test for the evaluation for septic arthritis
  • Synovial fluid culture
    • the most accurate test and must be performed before antibiotic administration
    • findings
      • fluid is usually purulent
      • Gram stain may be positive
        • 30-50% sensitive
      • white blood cell count > 50,000 cells/μL
Differential
  • Gout
  • Pseudogout
  • Inflammatory arthritis (e.g., rheumatoid arthritis)
  • Viral arthritis (e.g., hepatitis B and C and parvovirus B19)
Treatment
  • Medical
    • intravenous empiric antibiotics
      • indication
        • treatment of choice after athrocentesis is performed to target the most likely organism
          • antibiotics then becomes tailored to the specific organism when susceptibility results return
      • drugs
        • vancomycin
          • used when
            • Gram stain of synovial fluid shows gram-positive cocci
        • third-generation cephalosporin
          • used when
            • Gram stain of synovial fluid shows gram-negative bacilli
  • Operative
    • joint drainage
      • indication
        • used along with antibiotics to treat septic arthritis
          • septic arthritis represents a closed abscess
      • modalities
        • needle aspiration
        • arthroscopic drainage
        • arthrotomy
Complication
  • Osteomyelitis
  • Sepsis
 

Please rate topic.

Average 5.0 of 4 Ratings

Thank you for rating! Please vote below and help us build the most advanced adaptive learning platform in medicine

The complexity of this topic is appropriate for?
How important is this topic for board examinations?
How important is this topic for clinical practice?
Questions (1)
Lab Values
Blood, Plasma, Serum Reference Range
ALT 8-20 U/L
Amylase, serum 25-125 U/L
AST 8-20 U/L
Bilirubin, serum (adult) Total // Direct 0.1-1.0 mg/dL // 0.0-0.3 mg/dL
Calcium, serum (Ca2+) 8.4-10.2 mg/dL
Cholesterol, serum Rec: < 200 mg/dL
Cortisol, serum 0800 h: 5-23 μg/dL //1600 h:
3-15 μg/dL
2000 h: ≤ 50% of 0800 h
Creatine kinase, serum Male: 25-90 U/L
Female: 10-70 U/L
Creatinine, serum 0.6-1.2 mg/dL
Electrolytes, serum  
Sodium (Na+) 136-145 mEq/L
Chloride (Cl-) 95-105 mEq/L
Potassium (K+) 3.5-5.0 mEq/L
Bicarbonate (HCO3-) 22-28 mEq/L
Magnesium (Mg2+) 1.5-2.0 mEq/L
Estriol, total, serum (in pregnancy)  
24-28 wks // 32-36 wks 30-170 ng/mL // 60-280 ng/mL
28-32 wk // 36-40 wks 40-220 ng/mL // 80-350 ng/mL
Ferritin, serum Male: 15-200 ng/mL
Female: 12-150 ng/mL
Follicle-stimulating hormone, serum/plasma Male: 4-25 mIU/mL
Female: premenopause: 4-30 mIU/mL
midcycle peak: 10-90 mIU/mL
postmenopause: 40-250
pH 7.35-7.45
PCO2 33-45 mmHg
PO2 75-105 mmHg
Glucose, serum Fasting: 70-110 mg/dL
2-h postprandial:<120 mg/dL
Growth hormone - arginine stimulation Fasting: <5 ng/mL
Provocative stimuli: > 7ng/mL
Immunoglobulins, serum  
IgA 76-390 mg/dL
IgE 0-380 IU/mL
IgG 650-1500 mg/dL
IgM 40-345 mg/dL
Iron 50-170 μg/dL
Lactate dehydrogenase, serum 45-90 U/L
Luteinizing hormone, serum/plasma Male: 6-23 mIU/mL
Female: follicular phase: 5-30 mIU/mL
midcycle: 75-150 mIU/mL
postmenopause 30-200 mIU/mL
Osmolality, serum 275-295 mOsmol/kd H2O
Parathyroid hormone, serume, N-terminal 230-630 pg/mL
Phosphatase (alkaline), serum (p-NPP at 30° C) 20-70 U/L
Phosphorus (inorganic), serum 3.0-4.5 mg/dL
Prolactin, serum (hPRL) < 20 ng/mL
Proteins, serum  
Total (recumbent) 6.0-7.8 g/dL
Albumin 3.5-5.5 g/dL
Globulin 2.3-3.5 g/dL
Thyroid-stimulating hormone, serum or plasma .5-5.0 μU/mL
Thyroidal iodine (123I) uptake 8%-30% of administered dose/24h
Thyroxine (T4), serum 5-12 μg/dL
Triglycerides, serum 35-160 mg/dL
Triiodothyronine (T3), serum (RIA) 115-190 ng/dL
Triiodothyronine (T3) resin uptake 25%-35%
Urea nitrogen, serum 7-18 mg/dL
Uric acid, serum 3.0-8.2 mg/dL
Hematologic Reference Range
Bleeding time 2-7 minutes
Erythrocyte count Male: 4.3-5.9 million/mm3
Female: 3.5-5.5 million mm3
Erythrocyte sedimentation rate (Westergren) Male: 0-15 mm/h
Female: 0-20 mm/h
Hematocrit Male: 41%-53%
Female: 36%-46%
Hemoglobin A1c ≤ 6 %
Hemoglobin, blood Male: 13.5-17.5 g/dL
Female: 12.0-16.0 g/dL
Hemoglobin, plasma 1-4 mg/dL
Leukocyte count and differential  
Leukocyte count 4,500-11,000/mm3
Segmented neutrophils 54%-62%
Bands 3%-5%
Eosinophils 1%-3%
Basophils 0%-0.75%
Lymphocytes 25%-33%
Monocytes 3%-7%
Mean corpuscular hemoglobin 25.4-34.6 pg/cell
Mean corpuscular hemoglobin concentration 31%-36% Hb/cell
Mean corpuscular volume 80-100 μm3
Partial thromboplastin time (activated) 25-40 seconds
Platelet count 150,000-400,000/mm3
Prothrombin time 11-15 seconds
Reticulocyte count 0.5%-1.5% of red cells
Thrombin time < 2 seconds deviation from control
Volume  
Plasma Male: 25-43 mL/kg
Female: 28-45 mL/kg
Red cell Male: 20-36 mL/kg
Female: 19-31 mL/kg
Cerebrospinal Fluid Reference Range
Cell count 0-5/mm3
Chloride 118-132 mEq/L
Gamma globulin 3%-12% total proteins
Glucose 40-70 mg/dL
Pressure 70-180 mm H2O
Proteins, total < 40 mg/dL
Sweat Reference Range
Chloride 0-35 mmol/L
Urine  
Calcium 100-300 mg/24 h
Chloride Varies with intake
Creatinine clearance Male: 97-137 mL/min
Female: 88-128 mL/min
Estriol, total (in pregnancy)  
30 wks 6-18 mg/24 h
35 wks 9-28 mg/24 h
40 wks 13-42 mg/24 h
17-Hydroxycorticosteroids Male: 3.0-10.0 mg/24 h
Female: 2.0-8.0 mg/24 h
17-Ketosteroids, total Male: 8-20 mg/24 h
Female: 6-15 mg/24 h
Osmolality 50-1400 mOsmol/kg H2O
Oxalate 8-40 μg/mL
Potassium Varies with diet
Proteins, total < 150 mg/24 h
Sodium Varies with diet
Uric acid Varies with diet
Body Mass Index (BMI) Adult: 19-25 kg/m2
Calculator

Question locked
Sorry, this question is for
PEAK Premium Subscribers only
Upgrade to PEAK
Topic COMMENTS (0)
Private Note