SCINTIGRAPHIC EVALUATION OF FRACTURES OF THE DISTAL PHALANX IN HORSES - 27 CASES (1979-1988)

Retrospective radiographic and scintigraphic analyses were performed on 27 fractures of the distal phalanx in 25 horses. Location of technetium methylene diphosphonate (Tc-99m-MDP) uptake was compared with fracture line location as seen on radiography. Intensity (intense, moderate, mild) and pattern (focal, diffuse) of Tc-99m-MDP uptake was recorded and compared with duration of fracture. Nine horses were monitored during convalescence by obtaining additional scintigraphic views 3 to 68 months after injury. Palmar scintigraphic views had evidence of focal areas of increased Tc-99m-MDP uptake that corresponded to fracture line location as seen on radiography. Lateral scintigraphic views had evidence of diffuse increased uptake. There was a significant (P < 0.01) association between duration of fracture and intensity of uptake, with fractures < 3 months in duration more likely to have intense focal uptake. All fractures < 10 days in duration had intense focal uptake. As fracture age increased, Tc-99m-MDP uptake became less intense and more diffuse. Three fractures not evident on radiography had evidence of Tc-99m-MDP uptake on scintigraphy. Stall rest resulted in decreased Tc-99m-MDP uptake in 6 of 9 horses, but increased uptake was still visible in all horses between 4 and 25 months after injury. The only scintigraphic view without evidence of increased uptake was that obtained from a horse reexamined 68 months after injury.