Which imaging study is recommended to evaluate suspected slipped upper femoral epiphysis (SUFE) in adolescents?

Which imaging study is recommended to evaluate suspected slipped upper femoral epiphysis (SUFE) in adolescents?

• A. Limited internal rotation is most indicative sign
• B. Bilateral hip radiographs including frog-leg lateral views
• C. MRI pelvis
• D. Unilateral hip x-ray

Answer: (B)

Bilateral hip radiographs including a frog-leg lateral view are the preferred initial imaging when slipped upper femoral epiphysis (SUFE) is suspected. This matters because SUFE often involves both hips—either already bilaterally slipped or at risk to slip on the opposite side later. Imaging both hips at once helps catch a contralateral slip early and provides a baseline for comparison. The frog-leg lateral view is especially valuable because it places the hip in flexion, abduction, and external rotation, which makes posterior–superior displacement of the capital femoral epiphysis more evident than on a routine AP view. The AP pelvis view complements this by showing the overall alignment and may reveal signs such as physeal widening or disruption of Klein’s line that raise suspicion. If radiographs are inconclusive but suspicion remains, MRI can detect early occult slips and evaluate the growth plate, but it’s not the first-line test due to cost and availability. Relying on a unilateral hip x-ray risks missing a concurrent or future slip in the other hip.

Bilateral hip radiographs including a frog-leg lateral view are the preferred initial imaging when slipped upper femoral epiphysis (SUFE) is suspected. This matters because SUFE often involves both hips—either already bilaterally slipped or at risk to slip on the opposite side later. Imaging both hips at once helps catch a contralateral slip early and provides a baseline for comparison.

The frog-leg lateral view is especially valuable because it places the hip in flexion, abduction, and external rotation, which makes posterior–superior displacement of the capital femoral epiphysis more evident than on a routine AP view. The AP pelvis view complements this by showing the overall alignment and may reveal signs such as physeal widening or disruption of Klein’s line that raise suspicion.

If radiographs are inconclusive but suspicion remains, MRI can detect early occult slips and evaluate the growth plate, but it’s not the first-line test due to cost and availability. Relying on a unilateral hip x-ray risks missing a concurrent or future slip in the other hip.