- Pathophysiology
- Femoral epiphysis slips through the proximal physis (Salter-Harris Type 1 fracture).
- Epiphysis moves posteroinferiorly relative to the femoral neck.
- Classic Patient
- Obese adolescent male (12-16 yrs) during a growth spurt.
- Consider hypothyroidism if pt is <10 years old or not obese.
- Presentation
- Insidious onset of a limp and dull pain in the hip, groin, thigh, or referred knee pain.
- PE: Limited internal rotation of the affected hip. Leg held in external rotation.
- Diagnosis
- X-ray (AP and frog-leg lateral views).
- Klein’s line (line along superior femoral neck) fails to intersect the femoral head.
- Classic description: “Ice cream falling off the cone.”
- Treatment & Complications
- Immediate non-weight bearing (surgical emergency).
- Definitive Tx: Surgical in-situ screw fixation.
- Main Complications: Avascular necrosis (AVN) and chondrolysis.