51 year old male with history of alcohol abuse and bilateral previous knee surgeries presented with sudden onset right knee pain of 2 days duration and fever for two days.\u00a0 No known trauma.\u00a0 Patient febrile to 100.6 in PCP’s office.\u00a0 On arrival to hospital knee exam shows erythema, warmth, suprapatellar edema, knee effusion, pain with active and passive range of motion.\u00a0 WBC 23.<\/p>\n
Patient’s with new knee pain, swelling, erythema, fever and leukocytosis should be evaluated for septic arthritis.\u00a0 His risk factors included: alcohol abuse and previous knee surgery.\u00a0Known RFs for septic arthritis: age >80 years old, Diabetes mellitus, rheumatoid arthritis, prosthetic joint, previous joint surgery, IVDU, alcohol abuse, and recent skin infection.<\/p>\n
Most common route of infectious is hematogenous, but could also include spread from bone infection, spread from skin infection, or direct innoculation (bites\/trauma).<\/p>\n
Most common bacteria: staph aureus, then strep, and\u00a0minority are\u00a0gram negatives (consider in elderly, immunosuppressed, GI infections, trauma).\u00a0 Treatment is vancomycin, unless gram negative infection is suspected.\u00a0 If so, treat with ceftriaxone or ceftazidime.\u00a0<\/p>\n
Synovial fluid tap is important for diagnosis and treatment.\u00a0 WBC in fluid should be >50,000 and >75% polys but may be lower in immunosuppressed or partially treated infection.\u00a0 Always send gram stain and cultures (cultures from blood and synovial fluid).<\/p>\n