Common important differentials for paediatric hip pain include the following list. In an exam setting, clues to the diagnosis may include the patient's age, risk factors such as obesity/family history, and HPc (fever/viral illness). 

  • Developmental dysplasia of the hip
    • 0-3 years
    • Clinical features: Barlow, Ortolani positive. 
  • Legg-Calve-Perthes disease
    • 4-8 years
    • Clinical features: pain, stiffness, reduced ROM (esp. aBduction and internal rotation)
    • X-ray: widened joint space, flattening of the femoral head
  • Slipped upper femoral epiphysis (SUFE)
    • 10-15 years
    • RFs: Overweight
  • Transient synovitis
    • 2-10 years
    • HPc: recent viral illness
  • Septic arthritis

Developmental dysplasia of the hip

Age range

  • Newborns - 0 - 3 years

Examination findings

  • Leg length discrepancy
  • Reduced hip abduction due to contractures
  • Barlow’s sign positive - aDduct the hip with posterior pressure on the knee - a palpable sensation of subluxation/dislocation
  • Ortolani’s sign positive - flex the hips and knees and apply anterior pressure on the greater trochanters - a clunk is felt when the femoral head is relocated into the acetabulum 

Investigations 

  • Ultrasound if age < 6 months
  • AP pelvic XR if > 6 months

Management

  • Age < 6 months - Pavlik harness
  • Age 6-18 months - closed reduction with spica casting
  • Age > 18 months or failed treatment - open reduction and hip reconstruction

Legg-Calve-Perthes Disease

Pathophysiology

  • Idiopathic avascular necrosis of the femoral head

Clinical features

  • Age range: 4-8 years
  • Several weeks of limping
  • Hip pain (but may be painless)
  • Progressive hip stiffness
  • O/E: Antalgic gait, restricted ROM esp. aBduction and internal rotation 

Investigations

  • AP pelvic x-ray - initially widened joint space, then flattening of the femoral head

Transient Synovitis

Pathophysiology

  • Inflammation of the hip joint synovium, typically triggered by recent viral infection (commonly URTI)

Clinical Features

  • Age range: 2-10 years
  • Acute hip pain
  • Antalgic gait
  • Reduced ROM, especially abduction

Investigations

  • Septic arthritis must be ruled out - US can be useful
  • Bloods - elevated inflammatory markers - WCC/CRP

Management

  • Conservative - self-limiting disorder - Simple analgesia and rest 

Slipped Upper Femoral Epiphysis (SUFE)

Pathophysiology

  • Postero-inferior displacement of the femoral head epiphysis. 1/5 are bilateral. 

Clinica features

  • Age range: 10-15 years
  • RFs: Overweight, male
  • Pain in the hip or knee
  • O/E: Restricted ROM with loss of internal rotation and flexion

Investigations

  • AP pelvic x-rays

Management

  • Surgical