A 13-year-old boy has progressive hip pain with limp, no trauma, passive hip motion elicits pain. What is the most likely diagnosis?

A 13-year-old boy has progressive hip pain with limp, no trauma, passive hip motion elicits pain. What is the most likely diagnosis?

• A. Slipped Capital Femoral Epiphysis
• B. Legg-Calvé-Perthes disease
• C. Transient synovitis
• D. Septic arthritis

Answer: (B)

Chronic, insidious hip pain with a limp in a skeletally immature patient points toward Legg-Calvé-Perthes disease. It’s an idiopathic avascular necrosis of the femoral head, most classically seen in boys in early childhood, but it can present in older children as well. The hallmark is a gradual onset of groin or thigh pain with a limp, and the hip becomes stiff over time, especially with internal rotation and abduction. Pain during passive hip motion is common because the joint is effectively irritated by the altered femoral head and surrounding synovium, and guarding posture worsens the ROM limitation. In contrast, septic arthritis would typically present with fever, toxicity, and a rapidly painful, swollen joint; transient synovitis is usually shorter in duration and occurs in younger children; slipped capital femoral epiphysis tends to occur in slightly older adolescents with risk factors like obesity and shows particular changes in leg position and rotation. The described pattern fits Perthes best, linking the gradual, activity-limiting hip pain to a slowly progressive alteration of the femoral head.

Chronic, insidious hip pain with a limp in a skeletally immature patient points toward Legg-Calvé-Perthes disease. It’s an idiopathic avascular necrosis of the femoral head, most classically seen in boys in early childhood, but it can present in older children as well. The hallmark is a gradual onset of groin or thigh pain with a limp, and the hip becomes stiff over time, especially with internal rotation and abduction. Pain during passive hip motion is common because the joint is effectively irritated by the altered femoral head and surrounding synovium, and guarding posture worsens the ROM limitation. In contrast, septic arthritis would typically present with fever, toxicity, and a rapidly painful, swollen joint; transient synovitis is usually shorter in duration and occurs in younger children; slipped capital femoral epiphysis tends to occur in slightly older adolescents with risk factors like obesity and shows particular changes in leg position and rotation. The described pattern fits Perthes best, linking the gradual, activity-limiting hip pain to a slowly progressive alteration of the femoral head.