Perthes' disease

More limping

Step 1: View clinicals

A 9 year old caucasian girl presents with acute pain in her right hip for 1 day. She gives a history of chronic, progressively worsening pain in the same hip for the last 6 months. There is no history of trauma and she is otherwise asymptomatic. Her medical history is unremarkable and she is not on any medications.

Step 2: Order all relevant investigations

Full Blood Count

WBC/DC: 7,800/mm3 Lymphocytes: 35% Neutrophils: 62% Hb: 12.2 g/dL Hct: 37% Platelets : 230,000/mm3


The ESR is 5 mm in the first hour (normal). The C-Reactive protein level is < 6 g/l (normal).

X-Ray Pelvis and Hips

The X-ray of the right hip shows sclerosis and flattening of the right femoral head with early fragmentation. The lateral pillar height is decreased by < 50%. The pelvis and left hip appear normal.

MRI Right Hip

The MRI shows flattening, sclerosis and early fragmentation of the right femoral head, with a small joint effusion. The double-line sign is present.

Step 3: Select appropriate management

IV Antibiotics
Femoral Osteotomy
Total Hip Replacement

Score: ★★☆