THE EFFECTS OF INTRA-ARTICULAR ANESTHESIA ON SOFT TISSUE-AND BONE-PHASE SCINTIGRAPHY IN THE HORSE

Soft tissue- and bone-phase scintigrams were acquired from 4 normal horses before and over a 14-day period after metacarpophalangeal, antebrachiocarpal, tarsocrural and tarsometatarsal joint blocks. Images were evaluated subjectively and quantitatively for increased activity in these regions. The antebrachiocarpal block resulted in obvious focal accumulation of activity on soft tissue-phase scintigrams. This increased activity was greatest 2 to 4 days postanesthesia and persisted up to 14 days postanesthesia. On quantitative analysis of soft tissue-phase images, similar trends were noted after the metacarpophalangeal and tarsocrural blocks, but these increases were relatively mild and were not evident on subjective evaluation of the images. Abnormal soft tissue-phase activity was not associated with the tarsometatarsal block. On bone-phase scintigrams, increased activity was not present following any of these joint blocks.