Bacterial Arthritis

Septic or infectious arthritis is known as direct invasion of the joint space by various microorganisms (bacteria, viruses, mycobacteria and fungi. Reactive arthritis, a sterile inflammatory process may be a consequence of an infectious process located at a distance in the body. Although any infectious agent may cause arthritis , bacterial pathogens are the most significant due to rapid destructive nature. Due to the use prosthetic joint infection associated with these devices is most commonly found dangerous and septic arthritis.The two main classes of suppurative septic arthritis / or gonorrhea are bacterial nongonococice. Although Neisseria gonorrhoeae remains the most common disease-75% of cases among sexually active young people, Staphylococcus aureus is due to the vast majority of acute bacterial arthritis in adults and children over 2 years. This pathogen is the cause of arthritis affected 80% of rheumatoid arthritis.
Species such as Streptococcus viridans streptococci, Streptococcus pneumoniae and group B streptococci has over 20% of cases. Aerobic gram-negative hull are involved in 20-25% of cases. Most infections occur in elderly or very young, immunosuppression, intravenous drug abusers. Scaroiliace sternoclaviculare or joint infection with Pseudomonas aeroginosa or Serratia species occur exclusively in drug addicts. People with leukemia are prone to infection with Aeromonas.Polymicrobial infections, 10% of cases and infections with anaerobic organisms are a consequence of trauma or abdominal infection.
In the era preantibiotica death is a common complication in septic arthritis. Those who survived the destruction of the joint shows severe acute infections with fibrous or bony ankylosis. Fibrous ankylosis determine TB infection. Antibiotic therapy has reduced morbidity and mortality of the disease. The mortality rate is below 10%. Approximately 60% of patients recover completely. Prompt treatment limiting long-term destruction. Patients who are asymptomatic more than 7 days before diagnosis tended to report severe joint damage. Staphylococcus aureus and gram-negative bacilli tend to be more destructive. Children with septic arthritis of the hip shows the long-term disability. The prognosis is better for older children. Long term complications can occur pri growth disorders, fibrous or bony ankylosis or osteonecrosis of the femoral head.
Pathogenesis of arthritisPathogens invade the joint by direct inoculation, by contiguity from infected periarticular tissue or blood. Normal joint has several protective components. Synovial cells have phagocytic activity and bactericidal activity synovial fluid. Rheumatoid arthritis and systemic lupus erythematosus and alter the defensive functions fall chemotaxia and phagocytosis.Previously altered joints, especially those with rheumatoid arthritis are the most susceptible to infection. Synovial membranes of these adhesive joints shows neurovascularizatie and high, conditions that increase the chance of bacteremia. Some microorganisms bind the joint sialoproteina, fibronectin, elestina, hyaluronic acid prosthetic material.
Major consequence of bacterial invasion of joint destruction. As you continue the destructive process begins pannus formation and cartilage erosion on the sides of the joint. Large effusion infections occur in the balance, which affects the supply of blood and cause septic necrosis of bone.
There are three major prosthetic infections: early in the 3 months after implantation, the late at 3-24 months after implantation and more than 24 months after implantation. Percent of early cases and those caused by Staphylococcus aureus Staphylococcus aureus delayed by coagulase-negative and gram-negative aerobes. Both are acquired in the operating room. Late cases are secondary seal extending from various infectious marrow.
Signs and symptoms of bacterial arthritisSeptic arthritis occur at any age but predominantly affects young children. Occurs in children ages under 3 years. The incidence increases in adolescence with gonococcal infections. Joint infection is more common in elderly because of the increased number of risk factors and associated chronic diseases such as artificial joints. People with intravenous drugs have a high prevalence of septic arthritis varied with location: the sacral-iliac joint, and sternoclaviculara unusual microorganisms: Mycobacterium avium-intracellulare, aeruginoza Pseudomonas, Enterobacter.
Patient history should include:Nature of acute-onset joint pain-If pain is a chronic substance-History of joint disease or trauma-If the process is monoarticular or poliarticular-If the patient underwent venous catheterization or intravenous drug abuse-History of sexually transmitted diseases: Lyme disease, gonorrhea, hepatitis BConditions that affect host-defense-liver disease, diabetes, lymphoma, solid tumors, complement deficiencies, immunosuppressive drugs-Existing rheumatoid arthritis.
Septic arthritis may be difficult to diagnose in early stages of progression. Once developed purulent joint effusion and diagnoses are made quickly. Typically the patient has fever and a joint warm, red, painful, increased volume with decreased degree of motility. Restriction of movement occurs in active and passive actions.In younger patients, sexually active with fever, tenosynovitis, and migratory poliartralgie dermatitis is suspected gonorrhea. The rash appears as a papule on the trunk and extensor surfaces of distal extremity which converts to bleeding ulcers. Women develop predominantly gonococcal arthritis.
In children and infants is difficult to diagnose. Infants and children show signs of hidden inflammation. Symptoms of fever, poor appetite and irritability without obvious damage to joints can lead to an incorrect diagnosis. Besides the obvious open fractures, foreign objects and trauma, looking for a remote infection is important. Clinical presentation is similar to the child than the adult.But the child does not enable the affected joint. Additional symptoms may be present and leading to confusion, nausea, vomiting, headache, pharyngitis and abdominal pain. Ear infections are the most common source of bacteria for septic arthritis.
Tuberculous arthritis is usually monoarticulara, affecting the knee or hip. Most patients are middle-aged or elderly. Girl piogenica arthritis, chronic joint pain and tuberculosis cause minimal signs of inflammation. This condition leads to delayed diagnosis. Synovial cultures and histologic evaluation established the diagnosis.