Salter-Thompson classification of Perthes disease

The Salter-Thompson classification of Perthes disease simplifies the Catterall classification into two groups. Based on the radiographic crescent sign, we can distinguish:

  • group A: including Catteral groups I and II, where the crescent sign involves less than 50% of the femoral head
  • group B: including Catterall groups III and IV, where the crescent sign involves more than 50% of the femoral head

See also