A 13-year-old presents with groin pain radiating to the anterior thigh, antalgic gait, and external rotation of the leg. Which condition is most likely?

• A. Developmental hip dysplasia
• B. Osgood-Schlatter disease
• C. Legg-Calvé-Perthes disease
• D. Slipped capital femoral epiphysis

Answer: (D)

In adolescents, a sudden or progressive groin pain with an antalgic limp and the leg held in an externally rotated position strongly suggests a slipped capital femoral epiphysis. The femoral head slips through the growth plate at the top of the thigh bone, usually during puberty when growth plates are still open and weight-bearing stresses are high. As the head slips posteriorly and inferiorly, the limb tends to rotate outward, and pain often radiates to the groin or anterior thigh rather than the knee. You may also see limited internal rotation of the hip, especially when the hip is flexed. This condition is an orthopedic emergency because further slipping can damage the blood supply to the femoral head (avascular necrosis), so prompt imaging and surgical stabilization are essential. Obtain pelvic radiographs in both anteroposterior and frog-leg lateral views to confirm the diagnosis and determine the degree of slip. Treatment is urgent in-situ pinning (stabilization) to prevent further slip, with precautions to limit weight bearing until fixed. By contrast, developmental hip dysplasia is typically a condition of infancy; Legg-Calvé-Perthes disease tends to occur in younger children with insidious onset and different exam findings; Osgood-Schlatter disease affects the knee, not the hip.