A 12-year-old boy is brought to the office for evaluation of a limp. Since waking this morning, the patient has not been able to put any weight on his right leg due to hip pain. He has had this pain for the past 2 days and has been taking ibuprofen, but the pain has not improved. The patient plays in a baseball league and practices a few days a week. Last week, he fell during practice and scraped his right hip. The abraded area developed mild cellulitis, which was treated with topical antibiotic ointment. The patient has no chronic medical conditions or previous surgeries. Temperature is 38.9 C (102 F). Height is at the 30th percentile and weight is at the 70th percentile for age. On examination, the right hip is externally rotated and has pain with passive movement. The remainder of the examination is normal. Hemoglobin is 13 g/dL, platelets are 280,000/mm³, and leukocyte count is 18,000/mm³. Erythrocyte sedimentation rate is 52 mm/hr. Which of the following treatment options would be most beneficial in preventing long-term morbidity for this patient's condition?

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11ec25c8_d6d2_f844_bc81_832e2c10c17e_MD0003_00 This patient has fever, acute joint pain, and inability to bear weight associated with marked leukocytosis and elevated erythrocyte sedimentation rate. These findings are concerning for septic arthritis, a bacterial infection that can result in rapid and permanent joint destruction. Septic arthritis can develop from hematogenous spread of bacteria or from local extension of bacteria into the joint space from infected bone or skin; this patient's cellulitis could have led to either. Therefore, blood and synovial fluid cultures are required. Empiric intravenous antibiotics targeting the most common organisms (eg, Staphylococcus aureus, group A streptococci) are administered immediately after culture collection. Synovial fluid aspiration with >50,000/mm³leukocytes should prompt orthopedic consultation for emergency surgical drainage. Debridement and irrigation of the joint space are the most important interventions in preventing long-term morbidity. A delay in treatment can lead to femoral head necrosis, resulting in hip dislocation or leg-length discrepancy. Severe joint destruction may require total hip arthroplasty (Choice E). ³ (Choice A) Cast immobilization is appropriate management for a fracture, which causes acute leg pain (typically immediately following injury) but not fever. (Choice B) Intraarticular corticosteroid injection is a therapy for inflammatory arthritis, which usually presents with ≥6 weeks of joint pain and swelling rather than acute pain and fever. Steroid injection has no role in septic arthritis, and joint infection and osteonecrosis are potential complications of intraarticular steroids. (Choice D) Surgical pinning is the treatment for slipped capital femoral epiphysis, a condition seen in obese adolescents with progressive hip pain and limp. Fever and leukocytosis are not associated findings. Educational objective: Septic arthritis should be suspected when a patient has acute fever, joint pain, inability to bear weight, elevated erythrocyte sedimentation rate, and leukocytosis. Emergency surgical drainage and intravenous antibiotics are needed to prevent permanent joint destruction. References: Transient synovitis, septic hip, and Legg-Calvé-Perthes disease: an approach to the correct diagnosis. (http://www.ncbi.nlm.nih.gov/pubmed/25439014) Distinguishing pediatric Lyme arthritis of the hip from transient synovitis and acute bacterial septic arthritis: a systematic review and meta-analysis. (http://www.ncbi.nlm.nih.gov/pubmed/29581924)

A 12-Year-Old Boy Is Brought to the Office for Evaluation