• results from failure of the upper femoral epiphysis, which allows displacement of the femoral head on the femoral neck
• onset may be sudden, but more often is gradual
• pain frequently is referred to the knee, but can also occur in the hip
• limp and out-toeing are common, with loss of medial hip rotation
• majority of patients are 7-15 years old, and are aboce the 95th percentile for weight
• AP or frog-leg lateral xrays of the hip are diagnostic

References

Baskin MN. Injury-knee. In:Fleisher GR, Ludwig S, eds. Textbook of Pediatric Emergency Medicine. 4th ed. Philadelphia, Pa: Lippincott Williams & Wilkins; 2000:339-347

Staheli LT. Hip. In: Fundamentals of Pediatric Ortopoedics. 2nd ed. Philadelphia, Pa: Lippincott-Raven; 1998:68-71.