Coughlin classification

The Coughlin classification is the most widely used to type bunionettes. It relies on simple angle measurements on weight-bearing foot radiographs taken in the dorsoplantar projection . In 2013 DiDomenico et al added type IV .

Classification

  • type I: enlarged lateral surface of the head of the 5 metatarsal
  • type II
    • irregular lateral bowing of the distal 5 metatarsal
    • 4 to 5intermetatarsal angle (4-5 IMA) is normal
    • lateral deviation angle is abnormal
  • type III
    • 4 to 5 intermetatarsal angle (4-5 IMA) is abnormal
    • lateral deviation angle is normal
  • type IV: any combination of types I-III