Seymour bone fractures can affect children, teens, and adults. It is defined as an extra-articular transverse fracture of the base of the distal phalanx. We will break that down for you.
Each of the three separate bones that make up the finger is called a phalanges or phalanx. The distal phalanx is the far end of the middle phalanx. This is located at the base of the phalanx that forms the tip of the finger. So essentially, the fracture occurs between the bone that makes up the tip of the finger and the middle bone.
Extraarticular tells us the fracture is outside the joint. Transverse means the break goes through the area sideways (horizontal rather than vertical).
In children and skeletally immature adolescents (teens) the fracture line is usually entirely through the metaphyses, just past the growth plate. In adults, the fracture line is just distal to (past) where the extensor tendon attaches.
The nail bed is avulsed separated from the soft tissue but doesn’t always look avulsed. The surgeon must assess the injury carefully before just splinting the finger. The full length of the nail must be inspected. The nail bed could be torn underneath. If the cuticle seal is broken there may be an open fracture underneath.
Bleeding around the nail bed is a sign of an open fracture. X-rays should be examined closely for physeal (growth plate) injury in children. Additional problems develop when a Seymour fracture is not recognized and the finger is splinted or immobilized. Healing will not occur, infections are common, and the fracture remains unstable.
Surgery is necessary to pull the nail plate off and get the area cleaned out (a procedure referred to as irrigation and debridement). Only then will the fracture heal and nail bed repair itself. The recovery time is usually three to four weeks.