Fractured fibula can mimic irritable hip.

A traumatic limp is a common presentation in childhood, particularly in the under 5s. While the commonest diagnosis is irritable hip ascribed to a transient synovi-tis, there is a long list of other and more sinister diagnoses. Clinical algorithms have been suggested to allow diagnosis and management, while avoiding the need for extensive investigation in most children. 4 We present three cases where this approach missed the diagnosis of fractured fibula. A 20 month old child was referred by his general practitioner with a five day history of left sided limp. He was able to weight bear and had had an upper respiratory tract infection during the previous week. There was no history of trauma. He had a low grade fever. He had full range of movement of his hips and there was no local tenderness. Full blood count and C reactive protein were normal. The erythrocyte sedimentation rate was 25. A provisional diagnosis of irritable hip was made and he was managed conservatively. On review three days later his limp was worse and he had developed gastroenteritis. His erythrocyte sedimentation rate was 47. An ultrasound of his hips was normal and there was no ultrasonic evidence of periosteal reaction along his femur, tibia, or fibula. A bone scan the following day suggested a fracture of his left fibula. A plain radiograph revealed a healing fracture of the left mid-shaft fibula. A 20 month old child was referred to the Paediatric Department with a two week history of limp. His parents originally felt that he needed new shoes. He had an upper respiratory tract infection but no systemic upset. There was no history of trauma. He was not weight bearing on his left leg. His hips had a full range of pain free movement. The child had no bone pain, swelling, or tenderness. Full blood count and C reactive protein were normal. Erythrocyte sedimentation rate was 24. No radiological investigations were requested. A provisional diagnosis of irritable hip was made and he was managed conservatively. One week later his limp had improved but he cried when he jumped on his left foot. He walked with his left leg externally rotated. A plain radiograph of his hips and lower limbs revealed an undisplaced fracture of his mid-shaft fibula. A follow up radiograph one week later showed a healing fracture. A 15 month old child presented to the Paediatric Department with a …