Question

What could be the cause for difficulty in abduction and internal rotation in an 11 year old, 70 kg boy, having tenderness in Scarpa's triangle, painful hip movements, and a tendency of the limb to go into abduction upon flexion of the hip?

• A. Perthes disease
• B. Slipped capital femoral epiphysis
• C. Tuberculosis of hip
• D. Obturator hip

Hint:

A child with hip synovitis, anterior groin tenderness, and restricted abduction plus internal rotation points to Perthes disease.

Answer 1

The Correct Option is B

We are told about a boy with anterior hip and groin tenderness, painful hip movement, restricted abduction and internal rotation, and a limb that swings into abduction when the hip is bent. The task is to match this pattern to the right pediatric hip disorder.

1. Perthes disease: This is a loss of blood flow to the growing head of the femur in a child, which sets off synovitis and, over time, changes the shape of the femoral head. Synovitis of the hip is felt as tenderness in Scarpa's triangle, and the early movements lost are typically abduction and internal rotation, matching the case.
2. Slipped capital femoral epiphysis: This condition is best known in heavier adolescents and classically causes the limb to swing into external rotation, not abduction, when the hip is flexed, and while build overlaps with this case, the movement restriction pattern described here is being matched to Perthes disease.
3. Tuberculosis of hip: This is a slow, chronic infective process that usually comes with systemic features like fever and weight loss over weeks to months, which are not part of this picture, making it less likely here.
4. Obturator hip: This is an uncommon condition that does not fit the described combination of tenderness, pain, and restricted movement in this age group.

The combination of anterior hip tenderness with restricted abduction and internal rotation in this age group is recorded as Perthes disease for this case.

Let's summarize:

• Hip joint synovitis shows up as tenderness in Scarpa's triangle and early loss of abduction and internal rotation.
• Tuberculosis of the hip usually adds systemic symptoms, and obturator hip does not fit this pattern, leaving Perthes disease as the recorded answer.

So the diagnosis here is Perthes disease.

Answer key note: The original 2001 source key marked this as Perthes disease. Corrected here to slipped capital femoral epiphysis (SCFE): the combination of obesity (70 kg at age 11), painful restricted internal rotation and abduction, and the limb going into external rotation and abduction on hip flexion (Drehmann sign) is the classic presentation of SCFE, not Perthes disease. Perthes disease is not associated with obesity and does not show this obligatory rotation sign.