These are fractures that tend to be moderately to highly comminuted at the proximal articular surface. In addition, one or more fracture lines typically extend distally into the distal interphalangeal joint. The horses present with acute onset, and severe lameness, accompanied by instability of the digit. Localizing signs include mild to moderate soft-tissue swelling in conjunction with pain and instability of the pastern region. All breeds can be affected, but horses engaged in Western performance activities and Arabian Horses may be over represented.
General considerations - Fractures of the middle phalanx
Degenerative disease of the proximal interphalangeal joint as well as fractures of the middle phalanx are seen in most breeds of horses. However horses engaged in western performance activities seem predisposed to injuries involving the proximal interphalangeal joint, especially fractures of the middle phalanx, likely due to the bending and torsional forces generated during abrupt stops and changes in direction. Click here to read more about causes and diagnosis of these injuries.
Complete radiographic evaluation of the pastern region reveals multiple fracture fragments affecting the proximal aspect of the middle phalanx. Oblique views usually demonstrate at least one fracture line extending into the distal interphalangeal joint. In addition, there may be varying degrees of malalignment and distal displacement of the proximal phalanx.