Diagnosis and management of incomplete fracture of the distal palmar aspect of the third metacarpal bone in five horses.

Incomplete fracture of the distal palmar aspect of the third metacarpal bone was diagnosed in 5 horses. Mild to moderate lameness and positive response to flexion of the metacarpophalangeal joint were evident in all horses. Fractures were not detectable in 4 horses when the routine 30 degrees proximodorsal-palmarodistal radiographic view was used. Visualization of the fractures in these 4 horses required imaging of the palmar condylar surface by use of a dorsopalmar view of the flexed joint or a 125 degrees dorsoproximal-dorsodistal view. The dorsopalmar view of the flexed joint was used in a fifth horse to evaluate fracture healing when the fracture was no longer evident on routine radiographic views. Scintigraphy was used to locate the fracture sites in 2 horses. Treatment in all horses involved rest with gradual return to exercise, and all horses returned to their previous levels of racing. Scintigraphy and imaging of the palmar condylar surface of the third metacarpal bone allow for a more complete evaluation when other diagnostic images are within normal limits.