Septic Arthritis Dr.noori/Rheumatologist

Infectious Arthritis Septic Gonococcal Viral Fungal Tuberculous Lyme

Definition Acute joint infection due to bacterial agents Medical emergency

Epidemiology Incidence: 40-68/100000/ yr in Prosthetic joint 28-38/ 100000/ yr in RA 5- 12/ 100000/ yr in Children 2-5/ 100000/ yr in GP

} SEPTIC ARTHRITIS Infection of synovium and synovial fluid Seen in every ages Hip joint in children Knee in adults } frequent

In Adult: 75% with risk factor

Risk factors: Systemic: Local: Old age (>65 Y) RA DM Immunosuppressive Hemodyalisis Malignancy Local: OA Prosthetic joint

Etiology (microbiology) Microbial agent: Staphylococcus aureus: most common (75-80%) Other organism in special patients: Sexually active woman: Neisseria gonorrheae Elderly, IV drug abuser, immunocompromised, UTI: Gram negative (p. aeruginosa and E.coli) SLE: Salmonella HIV:Pneumococci, Salmonella, H. influenzae Alcoholism, Humeral immunity abnormality, Hemoglobinopathies: Pneumococcal infections Primary immunoglobolin deficiency: Mycoplasma

ETIOLOGY S. aureus → in every ages H. influenzae → 6 mo-5 years N. gonorrhoeae → >10 years, adults (in Western populations) Gram negative bacilli → Immune deficiency, urinary or intestinal invasive procedures, elderly people, renal failure, chronic joint disorders and diabetes

PATHOGENESIS Hemotogenous spread Spread through adjacent tissues Direct inoculation(aspiration/arthrotomy) *Rheumatic diseases are underlying disorders for septic arthritis -Structural abnormalities in the joint -Steroid use (abnormal phagocytosis…) *DM, immune def, hematological diseases, trauma, systemic infections…

Site of involvement: Mono (80-90%) Poly (more than 1 joint): RA Knee: 50% Hip: 13-20% Shoulder:10-15 %- Ankle: 5% Wrist: 5% Elbow: 5% SC: 5%- IV drug abuser SI: 2%- IV drug abuser Small joints of the hand andFoot : 2% Poly (more than 1 joint): RA

CLINICAL FEATURES Usually, there is a history of recent trauma/infection Frequently hip and knee joints Sacroiliac joint is affected in brucellosis Interphalangeal joints: human and animal bites Fever, fatigue, anorexia, nausea… Local findings of inflammation

Clinical manifestations Fever (toxic):60-80% Acute Sever pain Sever swelling of one joint Sever tenderness Warmth Sever effusion Sever limited ROM

DIAGNOSIS AND DIFFERENTIAL DIAGNOSIS Synovial fluid sampling: >50.000 leukocytes/ml (crystal arthropathies and RA) Leukocytes <50.000/ml (Malignancy, steroid use) Gram staining and culture Gram-positive bacteria 60%, Gram-negative bacteria 40%

Diagnosis Acute Monoarthritis Sepsis workup Biochemist Synovial Fluid Aspiration (rule)

کنتراندیکا سیونهای آرتروسنتز سلولیت بروی مفصل مورد نظر عفونت پوست مفصل پلاکهای پسوریازیس بروی مفصل باکتریمی(نسبی) مصرف داروهای ضد انعقاد

Acute Monoarthritis Sepsis workup Biochemist Synovial Fluid Aspiration Smear- Culture Light microscope

Acute Monoarthritis Sepsis workup Synovial Fluid Biochemist Aspiration Smear- Culture Light microscope Turbid - Purulent Leukocyte> 50,000/ml (> 90% PMN) Damaged WBC Crystal (-)

مایع مفصل سپتیک در 3 مورد WBCخیلی بالا نیست : 1)بیماران ایمنوساپرس 2)مصرف آنتی بیوتیک 3)اوایل عفونی شدن مفصل

Acute Monoarthritis Sepsis workup Synovial Fluid Biochemist Aspiration Smear- Culture Light microscope Positive Gram stain: 75% in s. aureus 30-50% in gram (-) Positive Fluid culture: 90% PCR: partially treated or culture negative

Acute Monoarthritis Sepsis workup Synovial Fluid Biochemist Aspiration Positive B/C : 50-70% Smear- Culture Light microscope Leukocytosis ESR & CRP Positive Gram stain: 75% in s. aureus 30-50% in gram (-) Positive Fluid culture: 90% PCR: partially treated or culture negative

Radiography Early:(1-7d) (baseline/exclude contiguous osteomyelitis) Soft tissue swelling Joint space widening Late (2-3 w): Erosion Joint space narrowing Periosteal new bone formation

DIAGNOSIS AND DIFFERENTIAL DIAGNOSIS PLAIN X-RAY -Expansion in joint space -Edema around the joint -Late structural findings Ultrasound -Collection of fluid in the joint and aspiration CT - Detection of associated osteomyelitis, joint fluid MR - Pyogenic sacroiliitis and spread of joint infection to surrounding structures

DIFFERENTIAL DIAGNOSIS Rheumatic fever Acute juvenile arthritis RA, gout, reactive arthritis Viral arthritis Fungal arthritis Tuberculous arthritis Osteomyelitis Cellulitis Bleeding into the joint (hemarthrosis)

TREATMENT Antibiotic Joint Drainage

TREATMENT Antibiotic Joint Drainage Empiric (IV): Smear Age or Risk factors Extra articular site

Empirical antibiotic Gram stain result: Gram positive cocci: Oxacillin or Naficillin (2g /q 4h) Vancomycin (1g /q 12h) if methycillin-resistant S. aureus Gram Negative: Ampicillin or Cephalosporin No organism: In healthy, sexually active: Cefotaxime or ceftriaxone In elderly debilitated patients: antistaphylococcal + Aminoglycoside + antipseudomonal penicillin or a third generation cephalosporin

TREATMENT Antibiotic Joint Drainage Empiric (IV): Smear Age or Risk factors Extra articular site Definitive therapy; based on culture

Definitive therapy S. aureous: 4 weeks Oxacillin Naficillin Vancomycin Pneumococal and streptococcal inf : 2 weeks Penicillin G, 2mU /q 4h H. influenzae and s. pneumoniae resistant to penicillin: 2 weeks Cefotaxime or Ceftriaxone Enteric gram negative: 3-4 w Second or Third Gen cephalosporin Fluoroquinolone (levofloxacin 500mg IV or Po every 24h) P. aeruginosa: 4 weeks Combination of AG + mezlocillin or ceftazidime (IV) 2 weeks Ciprofloxacin 750mg twice daily (oral) 2 weeks

TREATMENT Antibiotic Joint Drainage Empiric (IV): Closed needle Smear Age or Risk factors Extra articular site Closed needle Aspiration Arthrotomy: Hip, Shoulder Definitive therapy; based on culture

TREATMENT Antibiotic Joint Drainage Empiric (IV): Closed needle Smear Age or Risk factors Extra articular site Closed needle Aspiration Arthrotomy: Hip, Shoulder Arthroscopic Drainage: Symptom S. fluid volume S. fluid WBC S. fluid smear & culture Definitive therapy; based on culture

Frequent passive motion Until removal of inflammation signs TREATMENT Antibiotic Joint Drainage No weight bearing Frequent passive motion Until removal of inflammation signs