A 9-year-old boy is brought to the physician by his mother for a 2-day history of left hip and knee pain. He recently recovered from an upper respiratory tract viral infection. He has no past medical history. Vitals are normal. Leukocyte count is 9,000/μL. He is able to bear weight. Physical examination shows no erythema or warmth of the left hip. There is mild tenderness to palpation. BMI is 23. Which of the following is the most likely explanation for these findings?
Legg-Calve-Perthes
Primary hip dysplasia
Septic arthritis
Slipped capital femoral epiphysis
Toxic synovitis
