Child not moving any part of the limb should be suspected as having septic arthritis unless proven otherwise. The child will have pain on active and passive movement of the limb. Risk factors include low birth weight, NICU stay, umbilical vein catherization and central venous catheters. Joints commonly involved are hip, knee, elbow and ankle. Diagnosis of a joint infection is difficult because the child may not have abnormal blood test, may not have a high fever. Soft tissue ultrasound will usually reveal the diagnosis. Bone scan can be performed if ultrasound is negative and there is strong suspicion of osteomyelitis. MRI may be required in some cases to diagnose infection. Surgical management: Infections within a joint require prompt treatment in form of arthrotomy to prevent possibly permanent damage to joint cartilage.
All patients need anti-staphyloccocal coverage: Vancomycin and/or aminoglycoside. Neonates with NICU stay: risk for group B Streptococcus hence add Cefotaxime . Duration recommended is minimum 2 weeks of intravenous antibiotics followed by 4 weeks of oral antibiotics. In children with severe sepsis a prolonged course of intravenous antibiotics is recommended.