Radiographical features

Should be undertaken in patients eight to 15 years of age with new-onset limping and pain in the hip, groin, thigh, or knee (1).

Radiographs needed to diagnose

• stable SCFE - anteroposterior and frog-leg lateral views of both hips
• unstable SCFE - anteroposterior and cross-table lateral views of the involved side (the uninvolved side should be compared with this due to decreased range of motion of the hip) (1).

The radiographical features of SCFE include:

• Steel sign - a double density at the metaphysic on AP radiography (1)
• widening of the physis (growth plate) when compared to the uninvolved side
• relatively decreased height of the epiphysis
• Klein’s line - a line drawn along the superior edge of the femoral neck should normally intersect the epiphysis, but in SCFE patients the epiphysis falls below this line (1)

Also CT scanning allows an assessment of femoral neck anteversion.

Reference:

• (1) Peck D. Slipped capital femoral epiphysis: diagnosis and management. Am Fam Physician. 2010;82(3):258-62.